NASA Contractor Report 182263 

Performance Estimates for the Space 

Station Power System Brayton Cycle 

Compressor and Turbine 

Robert L. Cummings 

Litch$eld, Ohio 

August 1989 

Prepared for 

Lewis Research Center 

Under Purchase Order C-22 187-M 

National Aeronautics and 

Space Administration 

(#ASA-CR- 182263) PBRPOfHilNCE ESTXHATBS FOB N8 9 - 269 03 THE SPBCE ST1TIOY POWEB SPSTEX BR4YTOIJ CPCLB 

CCHIPBESSDR AND TURBINE final Report 

fCurminqs (Robert L.)) 35 p CSCL 21H Uoclas 

G3/20. 0224112 
TABLE OF CONTENTS 

Page 

1.0 SUMMARY .............................. 1 

2.0 INTRODUCTION ........................... 1 

2.1 DESCRIPTION OF CBC SYSTEM .................. 2 

2.2 NASA LEWIS BRAYTON COMPRESSOR AND TURBINE DATA ........ 2 

3.0 BRAYTON CYCLE COMPRESSOR ANALYSIS ................. 2 

3.1 

3.2 

3.3 

3.4 

3.5 

3.6 

3.7 

3.8 

3.9 

EFFECT OF REYNOLDS NUMBER .................. 2 

IMPORTANCE OF BRAYTON PERFORMANCE CLAIMS ........... 3 

METHOD OF CORRELATING COMPRESSOR PERFORMANCE ......... 3 

DESCRIPTION OF COMPUTER PROGRAM ............... 4 

PROCEDURE FOR COMPUTATION .................. 4 

CALCULATION OF EQUIVALENT CONDITIONS ............. 4 

CONVERSION OF ARGON TEST DATA ................ 4 

CALCULATION OF PARAMETERS FOR THE CBC ............ 5 

PREDICTION OF THE CBC COMPRESSOR PERFORMANCE ......... 5 

4.0 BRAYTON CYCLE TURBINE ANALYSIS .................. 5 

4.1 EFFECT OF REYNOLDS NUMBER .................. 5 

4.2 GENERAL DESCRIPTION OF ANALYSIS METHOD ............ 6 

4.3 COMPUTER PROGRAM AND PROCEDURE FOR COMPUTATION ........ 7 

4.4 CONVERSION OF ARGON TURBINE TEST DATA ............ 7 

4.5 CALCULATION OF PARAMETERS FOR THE CBC TURBINE ........ 7 

4.6 PREDICTION OF THE CBC TURBINE PERFORMANCE .......... 7 

5.0 EFFECTS OF OTHER VARIABLES .................... 8 

6.0 CONCLUDING REMARKS ........................ 8 

APPENDIX A . LIST OF COMPRESSOR MATCHING SYMBOLS ........... 9 

APPENDIX B . TURBINE MATCHING SYMBOLS ................ 10 

APPENDIX C . BRAYCOMP.BAS PERFORMANCE PREDICTION PROGRAM ....... 11 

APPENDIX D . BRAYTURB.BAS PERFORMANCE PREDICTION PROGRAM ....... 16 

REFERENCES .............................. 21 
PERFORMANCE ESTIMATES FOR THE SPACE STATION POWER SYSTEM BRAYTON 

CYCLE COMPRESSOR AND TURBINE 

Robert L. Cummings, Consultant 

2778 Avon Lake Road 

Litchfield, Ohio 44253 

1.0 SUMMARY 

The methods which have been used by the NASA Lewis Research Center for 

predicting Brayton Cycle compressor and turbine performance for different gases 

and flow rates are described. These methods were developed by NASA Lewis during the early days of Brayton cycle component development and they can now be 

applied to the task of predicting the performance of the CBC Space Station 

Freedom power system. 

Computer programs are given for performing these calculations and data 

from previous NASA Lewis Brayton Compressor and Turbine tests is used to make 

accurate estimates of the compressor and turbine performance for the CBC power 

system. Results of these calculations are also given in following sections of 

this report. 

This work has been sponsored by NASA in order to obtain an independent 

evaluation of the performance of the CBC power system. In general, these calculations confirm that the CBC Brayton Cycle contractor has made realistic compressor and turbine performance estimates. 

2.0 INTRODUCTION 

NASA has selected the closed Brayton cycle as the solar dynamic power sysThe accuracy of the performance predictions made by the contractem for the Space Station. This system uses helium-xenon mixture of 39.94 

molecular weight and has an electrical output of the 30.7 kW at a reference 

design point. 

tor for the aerodynamic components of this system can be evaluated and established by reference to the extensive history of developmental and endurance 

testing previously performed on Brayton Cycle components at the Lewis Research 

Center. 

The closed Brayton cycle system (known as the CBC) has been chosen for 

development for the Space Station electric power system since it has a high 

cycle efficiency and the working fluid is an inert, noble gas. This provides 

the advantage of single phase operation throughout the cycle, eliminating 

uncertainties associated with boiling and condensing while in orbit. The CBC 

has also achieved many thousands of hours of successful operation in development testing and is closely related to auxiliary power units and turbochargers 

which have accumulated millions of operating hours in aircraft and in vehicles. 

This report provides a method for estimating aerodynamic performance of 

the CBC compressor and turbine by reference to the previous Brayton component 

test results. Taken into account will be the change in the working gas and 

also the change in size and flow rate. 

from one gas to another by establishing equivalent vector diagrams at the 

impeller inlets and exits and by equalizing Reynolds numbers. 

The performance will be correlated 

The CBC 

1 
component performances will then be estimated by using data from several of 

the previous tests which were performed by NASA Lewis. The remainder of th 

report is devoted to these issues. 

2.1 DESCRIPTION OF CBC SYSTEM 

The CBC power system utilizes a radial outflow compressor and a radial 

inflow turbine. These are mounted on a single shaft, supported on gas lubr 

cated foil-type bearings, with a straddle mounted four pole Rice alternator 

integral with'the shaft. 

pressor and the turbine, is given in figure 1. The remainder of the CBC gas 

system consists of a solar heat receiver, with integral thermal energy storages a waste heat recuperator, and a heat rejection cooler. 

ing of this system is shown in figure 2. 

state point conditions for the typical CBC operating point. 

The CBC rotor layout, showing dimensions of the comA schematic drawOn the figure is also given the 

2.2 NASA LEWIS BRAYTON COMPRESSOR AND TURBINE TEST DATA 

During the extensive period beginning in the early 1960's NASA Lewis conThese were on different size 

ducted performance evaluation and improvement tests on a number of different 

designs of the Brayton compressors and turbines. 

units, operating over a range of weight flows and Reynolds numbers and the 

tests were directed both toward establishing the performance level which can 

be obtained from these relatively small machines and toward finding possible 

aerodynamic performance improvements. 

This background of test data provides a valuable source from which the 

performance of the CBC system for the Space Station can be accurately 

predicted. 

3.0 BRAYTON CYCLE COMPRESSOR ANALYSIS 

A summary of the sizes of three of the compressors which were tested is 

given in table I. This data was taken using argon gas. Also given in this 

table is the design point weight flow, the inlet pressure and pressure ratio, 

the inlet temperature, the design point measured efficiency, and the Reynolds 

number. 

The reference numbers of the NASA reports which served as the source of 

the data is also given. 

attached to this report. The final column, given in table I, is the equivalent data for the Brayton compressor for the CBC He/Xe power system. 

These numbers refer to the list of references, 

3.1 EFFECT OF REYNOLDS NUMBER 

Prior NASA test results have established that Reynolds number has a pronounced effect on Brayton systems compressor performance. These effects are 

described and discussed in reference 1. As the Reynolds number was decreased, 

a progressive degradation of efficiency was observed. 

number was also found to reduce the maximum flow, the maximum pressure ratio, 

and the flow at the surge point. Effects on the compressor work factor, the 

slip factor, and the windage factor were also noted. 

A decreased Reynolds 

The Brayton system compressor for the Space Station will operate at a 

higher Reynolds number than the prior NASA and contractor tests. The above 

2 
noted effects will therefore all 

present review of the Space Stat 

the effect of Reynolds number on 

As established in reference 

be beneficial. The chief concern for 

on Brayton system performance evaluat 

compressor adiabatic efficiency. 

the 

on is 

1 and by a number of additional test programs, the relation between the compressor efficiency (ETAC), or more specifically the loss (1 - ETAC), and the Reynolds number is found to be: 

(1 - ETACN>/(l - ETACK) = (REK/RENIN 

where ETACK and REK are known values of adiabatic efficiency and Reynolds 

number which are used as a reference point to predict a new value of ETACN, 

the efficiency, at another value of REN, a new Reynolds number. The value of 

the exponent N, shown to be appropriate in reference 1 for the Reynolds 

number range of interest for the Solar Brayton cycle, is 0.20. The value for 

the loss exponent is, of course, based on the supposition that proper matching 

is maintained between the impeller and the diffuser. 

3.2 IMPORTANCE OF BRAYTON PERFORMANCE CLAIMS 

During the proposal evaluation phase of the space station dynamic power 

system selection process, it has been essential to accurately establish the 

efficiencies that would be obtainable from the competitive power systems. As 

the development program begins, it is also essential to confirm that realistic 

performance claims have been made for the Solar Brayton cycle turbocompressor 

since this will be a new design and new hardware that has not previously been 

built and tested. The solar collector, the radiator, the alternator and the 

heat transfer components, will also be new and will be designed and built to 

match the output of the turbocompressor. The procedures described in this 

report are also of interest and value for possible future performance estimates of different sized Brayton cycle systems. 

3.3 METHOD OF CORRELATING COMPRESSOR PERFORMANCE 

The procedures for predicting the performance of a centrifugal compressor 

for a new gas, when its performance is known on a different gas, is described 

in several of the reports named in the attached REFERENCES. In particular reference 1 has a good discussion. 

Briefly, the basic principle of matching performance of a compressor of a 

given size and geometry between different gases is to establish geometric similarity between the vector diagrams for both gases at the compressor inlet and 

exit and also to adjust the inlet pressure so as to match Reynolds numbers. 

This is accomplished as follows: 

(1) Assume a constant slip factor, inlet flow coefficient, efficiency, 

and static density ratio across the impeller, and, using, an iterative process, determine the overall pressure ratio and the wheel speed for the new gas. 

(2) Also determine the weight flow and the inlet pressure for the new 

gas so as to match the Reynolds number. 

If the compressor size is to be modified, with all geometric parameters 

maintained similar, the weight flow and the inlet pressure must be properly 

3 
adjusted and the Reynolds number recomputed for the new set of conditions. 

The efficiency may then be estimated for the new size, as previously discussed. 

3.4 DESCRIPTION OF COMPUTER PROGRAM 

The procedure for matching compressors between different gases, while 

straightforward in concept, is complicated to perform, since the compressible 

flow and energy input equations cannot be solved in closed form and a series 

of iterations is required. A BASIC computer program has therefore been produced to perform these computations. 

compatible computers, has been named BRAYCOMP.BAS. 

is attached to this report. 

This program, written for the IBM PC and 

A listing of this program 

This program has been written to output results to the CRT screen, to a 

printer, or to a data file for subsequent manipulation or plotting by a data 

base program. 

the design point performance results for three Brayton compressors which were 

tested by the NASA Lewis Research Center. Input statements for the geometric 

values and the proposed performance of the CBC system are also included. 

modynamic properties and formulas for determining viscosity for air, argon, 

and the He/Xe mixture of 39.95 molecular weight are also contained. Properties for neon, krypton, and He/Xe mixtures of different molecular weights 

could also be easily added. 

space station the He/Xe mixture of molecular weight 39.95 (referred to as 

He/Xe(39.95>> is the one which should be selected. 

It also contains input statements with the geometric values and 

TherFor computation of the Brayton system for the 

3.5 PROCEDURE FOR COMPUTATION 

A brief description of the procedure for using this program is as follows: 

(1) Enter BASIC on the PC and open BRAYCOMP.BAS. 

(2) Make the selection between SCREEN, PRINTER, or DATAFILE, for output. 

analysis, if desired. 

The DATAFILE option creates a new file which may be used for additional 

(3) The final entry step is to make the selection for the compressor 

diameter and the known and new working gases. 

The above selections are made in response to questions which appear on 

the CRT screen, so that the choices can be readily made. 

3.6 CALCULATION OF EQUIVALENT CONDITIONS 

NASA Lewis has previously conducted tests on Brayton cycle compressors 

using air and several monatomic gases and gas mixtures. In most instances, 

these tests were performed several times on compressors of different geometries. 

tion of equivalent performances for different gases, as described in this 

report, are indeed correct and accurate. 

This multiple testing allowed verification that the methods of predic3.7 CONVERSION OF ARGON TEST DATA 

These prediction methods will therefore now be applied utilizing data 

that was initially obtained in the NASA Lewis compressor component performance 

4 
evaluation tests so as to 

molecular weight 39.95, m 

station CBC. The three s 

obtain an estimate of performance for the He/Xe, 

xture which has been selected for use in the space 

zes of the comDressors for which these Dredictions 

are to be made, as previously given in table I, are tip diameters'of 4.25, 

5.976, and 6.44 in. The known data for these predictions has been obtained 

from references 2, 1, and 3. The calculations for the 4.25, the 5.976, and 

the 6.44-in.-diam. compressors are summarized in tables 11, 111, and IV, 

respectively. 

3.8 CALCULATION OF PARAMETERS FOR THE CBC 

Estimates of the performances of the CBC compressor, using the He/Xe 

(molecular weight 39.95) working fluid, have been made by the Garrett Corporation and presented in the space station power system proposal. The geometric 

data and the performance estimates made by Garrett have been entered in the 

BRAYCOMP.BAS program and have been converted from He/Xe (39.95) to argon. 

This allows a direct comparison with the results of the previous tests in 

which argon was used. These results are given in table V. 

3.9 PREDICTIONS OF THE CBC COMPRESSOR PERFORMANCE 

An independent estimate of the adiabatic efficiency of the CBC compressor 

can now be made, using the CBC calculated Reynolds number, as listed in 

table V. 

measured argon data from NASA Lewis tests (as given in tables I1 to IV) by use 

of the 0.2 exponential power of the Reynolds ratio. 

This can be accomplished by converting the loss fractions from the 

The computed mean efficiency value of 0.843 in table VI may be seen to 

compare very closely with the Garrett Corporation CBC compressor efficiency 

prediction. 

6.44-in.-diam. compressor test data would seem to provide further assurance 

that a CBC compressor efficiency will be obtained that will be at least as 

high as that predicted by the contractor. 

The higher computed value determined from the data from the 

4.0 BRAYTON CYCLE TURBINE ANALYSIS 

A summary of the sizes of the three turbines which were tested by NASA 

Lewis and which have been used to estimate the CBC turbine efficiency is given 

in table VII. This data is for use of argon gas. Also given in this table is 

the design point weight flow, the inlet pressure and pressure ratio, the inlet 

temperature, the design point measured efficiency, and the Reynolds number. 

The reference numbers of the NASA reports which served as the source of this 

data is also given. These numbers refer to the list of references, attached 

to this report. 

Brayton turbine proposed for the CBC He/Xe power system. 

The final column, given in table VI1 is the design point data for the 

EFFECT OF REYNOLDS NUMBER 

ts have been established that Reynolds number also 

Brayton systems turbine performance, These 

4. 

NASA turbine test resu 

has a significant effect on 

effects are described and d 

found that, as the Reynolds 

scussed in reference 4. 'During these tests it was 

number was decreased, a progressive degradation of 

5 
efficiency was observed. Decreasing Reynolds number was also found to slightly 

reduce the turbine flow. 

The Brayton system turbine for the space station will operate at a 

higher Reynolds number than the prior NASA and contractor tests. The above 

noted effects will therefore all be beneficial. The chief concern for the 

present review of the space station Brayton system performance evaluation is 

the effect of Reynolds number on the turbine adiabatic efficiency. As established by reference 4 and by a number of additional test programs, the relation between the turbine efficiency (ETAI), or more specifically the loss 

(1 - ETAT), and the Reynolds number is found to be: 

(1 - ETATN)/(l - ETATK) = A + B * (REK/RENIN 

where ETATK and REK are known values of adiabatic efficiency and Reynolds 

number which are used as a reference point to predict a new value of ETATN, 

the turbine efficiency at another value of the new Reynolds number (REN). The 

values of the constants A and B and the exponent N, shown to be appropriate in 

reference 4 for the Reynolds number range of interest for the Solar Brayton 

cycle, are A = 0.4, B = 0.6, and N = 0.20. The values for these loss constants are, of course, based on the supposition that good aerodynamic designs 

are maintained for the inlet nozzles, the impeller and the exit diffuser. 

These values for the loss constants will then subsequently be used to predict 

the CBC turbine performance from the measured efficiencies of the prlor tests. 

I 4.2 METHOD OF CORRELATING TURBINE PERFORMANCE 

The procedures for predicting the performance of a radial inflow turbine 

for a new gas, when its performance is known for a different gas, is described 

in several of the reports named in the attached List of References. In particular, reference 6 has a good discussion, giving an example of the equivalence 

of air and argon performance for the 6.02-in.-diam. turbine. 

description of the method is as follows: 

A general 

The basic principle of matching performance of a turbine of a given size 

and geometry between different gases is similar to that previously described 

for the compressor. Again it is needed to establish geometric similarity 

also to adjust the flow rate so as to match Reynolds numbers. This is accomplished as follows: 

I between the vector diagrams for both gases at the turbine inlet and exit and 

, 

(1) Determine the weight flow for the new gas so as to match the 

Reynolds Number. 

(2) Adjust the rotational speed, the inlet pressure, and the total to 

static pressure ratio so as to obtain the same equivalent flow, 

equivalent speed, and equivalent specific work. 

If the turbine size is to be modified, with all geometric parameters maintained similar, the weight flow and the inlet pressure must then be properly 

adjusted and the Reynolds number recomputed for the new set of conditions. 

I The efficiency may then be estimated for the new size, as previously discussed. 

6 
4.3 COMPUTER PROGRAM AND PROCEDURE FOR COMPUTATION 

A listing of a BASIC computer program named BRAYTURB.BAS, which is used 

to perform turbine matching computations is attached to this report. 

gram already contains size and performance data for the 4.59, the 4.97, and 

the 6.02-in.-diam. turbines which were tested by NASA Lewis. The size and 

estimated performance data for the CBC turbine is also included. 

discussion and description of the procedure for computation previously given 

for the compressor also applies to use of this turbine program. 

This proThe further 

4.4 CONVERSION OF ARGON TURBINE TEST DATA 

These prediction methods will now be applied utilizing the data that was 

initially obtained in the NASA Lewis turbine component performance evaluation 

tests so as to obtain an estimate of the turbine performance for the He/Xe, 

molecular weight 39.95, mixture which has been selected for use in the space 

station CBC. The three sizes of the turbines for which these calculations are 

to made were previously given in table VI1 with tip diameters of 4.59, 4.97, 

and 6.02 in. The known data for these predictions has been 

obtained from references 4, 5, and 6, and the calculations are summarized in 

tables VIII, IX, and X. 

4.5 CALCULATION OF PERFORMANCE OF THE CBC TURBINE 

Estimates of the performances of the CBC turbine, using the He/Xe (molecular weight 39.95) working fluid, have been made by the Garrett Corporation and 

presented in the space station power system proposal. The geometric data and 

the performance estimates made by Garrett have been entered in the BRAYTURB.BAS 

program and have been converted from He/Xe (39.95) to argon. This allows a 

direct comparison with the results of the previous tests in which argon was 

used. These results are given in table XI. 

4.6 PREDICTION OF THE CBC TURBINE PERFORMANCE 

An independent estimate of the adiabatic efficiency of the CBC turbine 

can now be made, using the CBC calculated Reynolds number as listed in 

table XI. This can be accomplished by converting the loss fractions from the 

measured argon data from NASA Lewis turbine tests (as given in tables VIII, 

IX, and X> by use of the equation using 0.2 exponential power of the Reynolds 

number ratio, previously given: 

(1 - ETATN)/(l - ETATK) = 0.4 + 0.6 * (REK/REN)Oa2 

This computation is summarized in table XII. The computed mean efficiency value of 0.883 is found to be a significant amount lower than the 

Garrett Corporation CBC turbine efficiency prediction of 0.897. 

computed values determined from the data from the 4.97- and the 6.02-in.-diam. 

turbine tests would seem to somewhat modify this result, but both of these 

tests predict an efficiency of about 0.007 below the CBC estimate. 

The higher 

A further direct experimental result, reported in reference 6 (TN D-2987), 

can also be used to check the above estimates. Here a measured total efficiency of 0.90 was reported for an air test of the 6.02-in.-diam. turbine at 

a Reynolds number of 225x103. 

of efficiency of 0.88, measured for the 6.02-in.-diam turbine at the Reynolds 

Interpolation between this result and the value 

7 
number of 64x103, results in a CBC estimated adiabatic total efficiency of only 

0.888. 

In evaluating the above results, however, it should be considered that 

the CBC turbine, having a tip diamenter of 7.65 in., would also be expected to 

obtain some performance advantage from direct effect of scale and tip clearance 

ratio. This is further discussed in the following sections. 

5.0 EFFECTS OF OTHER VARIABLES 

In order to make a complete evaluation of the performance potential of 

the CBC compressor and turbine it would be necessary to consider the effects 

of such things as disk and vane clearances, inlet and exit Mach numbers, diffuser vane angle setting, and the design of the subsonic exit diffusers. 

These factors have all been found in prior NASA Lewis research programs to 

have significant effect on the efficiency of the Brayton cycle compressors and 

turbines. Both the CBC compressor and the turbine, however, will have a close 

family resemblance to previously tested units. 

and construction variables may therefore be expected to have only a secondary 

effect on efficiency. 

The above enumerated design 

6.0 CONCLUDING REMARKS 

This report has described the method whereby the measured performance of 

a Brayton cycle radial outflow centrifugal compressor and a radial inflow turbine, using a gas which has one set of thermodynamic properties, may be used 

to accurately predict the performance of an identical compressor and turbine, 

when operated with a gas having different properties. 

The method for correcting the predicted performance of a geometrically 

similar compressor or turbine, when it is scaled upward or downward in size is 

a1 so descri bed. 

Two BASIC computer programs are also included, in order that these types 

of performance computations can be made for any compressor or turbine performance matching application. 

This program has then been used to predict the performance of the CBC 

compressor and the CBC turbine, using He/Xe, based upon measured argon tests 

results, obtained during prior NASA Lewis Brayton cycle development and 

research programs. 

compressor efficiency estimate has been made by the Brayton Cycle System Contractor. The turbine efficiency estimate compares reasonably well when consideration is given to possible direct effects of scale and turbine rotor inlet 

and exit diffuser differences. Further considerations may be warranted, however, in order to determine the reasons and the possible effects of the 

slightly lower predicted turbine efficiency. 

These computations appear to confirm that an accurate 

8 
APPENDIX A 

COMPRESSOR MATCHING SYMBOLS 

This is a list of symbols for the Brayton Cycle Compressor matching program 

(BRAYCOMP.BAS>. This program provides matching for air and several different inert 

gases. A symbol ending with K refers to the known gas; one ending with N refers to 

the new gas. For example: CPK = Specific heat, known and CPN = Specific heat, new. 

However, in some cases the ending K is omitted. 

AR3 = Exit flow area (in.2) NN = rpm, new gas 

AT3 = Exit stagnation sonic velocity (ft/sec) NS = Specific speed 

AM2 = Inlet flow area (in.2) P2 = Inlet total pressure (lb/in.2> 

BH = Exit blade height (in.) P2N = Inlet total pressure, new 

CPK = Specific heat, known gas (Btu/lb-"F) PHI = Inlet flow coefficient, known 

CPN = Specific heat, new gas (Btu/lb-"F> 

DEL1 = Inlet velocity error increment 

DEL2 = Exit velocity error increment 

DI = Inlet tip diameter (in.) 

DR = Static density ratio 

DRN = Static density ratio, new 

DH = Inlet hub diameter (in.) 

DT = Tip diameter (in.) 

DTA = Actual temperature rise (OR) 

DTI = Ideal temperature rise (OR) 

ETAC = Compressor adiabatic efficiency 

ETACI = Impeller efficiency 

FCW = Compressor work factor 

FW = Windage factor 

G = 32.17 ft/sec2 

GAMK = Specific heat ratio, known 

GAMN = Specific heat ratio, new gas 

H = Ideal head rise (ft) 

HN = Ideal head, new (ft) 

K2&K3 = Known flow functions 

K2N&K3N = New flow functions 

KG$ = Name, known gas 

MK = Molecular weight, known gas 

MN = Molecular weight, new gas 

MU2K = Viscosity, known (lb/ft-sec) 

MU2N = Viscosity, new (lb/ft-sec) 

NG$ = Name, new gas 

NK = rpm, known 

NKEQU = Corrected rpm, known 

CN = 720/PI = 229.18 

DEL = P1/14.7 

FS = FCW - FW 

J = 778.16 ft - lb/BtU 

PHIN = Inlet flow coefficient, new 

PR = Pressure ratio, known 

PRN = Pressure ratio, new 

RH02 = Inlet static density (lb/ft3> 

RH02N = Inlet static density, new 

PI = 3.14159 

RH03 = Exit static density 

RH03N = Exit static density, 

REK = Reynolds number, known 

REN = Reynolds number, new 

RK = Gas constant, known gas 

RN = Gas constant, new gas 

T2 = Inlet total temoerature 

new 

(OR> 

T2N = Inlet total temperature, new (OR> 

T3 = Exit total temperature (OR> 

T3N = Exit total temperature, new (OR> 

UTK = Tip speed, known (ft/sec) 

UTN = Tip speed, new gas 

VM2 = Inlet merid. velocity 

VTT2&VT2 = Velocity ratio function 

VTT3&VT3 = Exit velocity function 

WK = Weight flow, known (lb/sec> 

WN = Weight flow, new gas (lb/sec) 

WEQU = Corrected weight flow 

XK = (GAMK - l)/GAMK, known 

XN = (GAMN - l>/GAMN, new 

X2K = (GAMK - 1>/2, known 

X2N = (GAMN - 1>/2, new 

YK = l/(GAMK - 1>, known 

YN = l/(GAMN - 1). new 

THETA = T2/518.7 

9 
APPENDIX B 

LIST OF TURBINE MATCHING SYMBOLS 

This is a list of symbols for the Brayton Cycle Turbine matching program 

(BRAYTURB.BAS>. This program provides matching for air and several different inert 

gases. A symbol ending with K refers to the known gas; one ending with N refers 

to the new gas. 

However, in some cases the ending K is omitted 

For example: CPK = Specfic heat, known & CPN = Specific heat new. 

AR2 = Inlet flow area (in.2> 

ALPH2 = Stator exit angle (deg) 

AT3 = Exit stagnation sonic velocity (ft/sec) P2N = Inlet total pressure, new 

AM3 = Exit flow area (in.2> 

NU = Blade to jet speed ratio 

P2 = Inlet total pressure (lbs/in.2> 

BW = Inlet blade width (in.) 

CPK = Specific heat, known gas (Btu/lb-"F> 

CPN = Specific heat, new gas (Btu/lb-"F> 

DEL1 = Inlet velocity error increment 

DEL2 = Exit velocity error increment 

DELH = Specific work (Btu/lb> 

DE = Exit tip diameter (in.) 

DH = Exit hub diameter (in.) 

DHEQU = Air standard specific work (Btu/lb> 

DT = Tip diameter (in.) 

DTA = Actual temperature rise (OR) 

DTI = Ideal temperature rise (OR) 

EPSI = Function of gamma 

ETAT = Total to total efficiency 

ETAS = Total to static efficiency 

G = 32.1 ft/sec2 

GAMK = Specific heat ratio, known 

GAMN = Specific heat ratio, new gas 

H = Ideal head drop (ft) 

HN = Ideal head, new 

K2&K3 = Known flow functions 

K2N&K3N = New flow functions 

KG$ = Name, known gas 

MK = Molecular weight, known gas 

MN = Molecular weight, new gas 

MU2N = Viscosity, new (lb/ft-sec> 

NG$ = Name, new gas 

NK = rpm, known 

NKEQU = corrected rpm, known 

NN = rpm, new gas 

NS = specific speed 

YN = l/(GAMN - l), new 

CN = 720/PI=229.18 

DEL = P1/14.7 

J = 778.16 ft-lb/BtU 

I MU2K = Viscosity, known(lb/ft-sec) 

PI = 3.14159 

PR = Total pressure ratio 

PRS = Total to static pressure 

PRN = Pressure ratio, new 

RH02 = Inlet static density (lb/ft3> 

RH02N = Inlet static density, new 

RH03 = Exit static density 

RH03N = Exit static density, new 

REK = Reynolds number, known 

REN = Reynolds number, new 

RK = Gas constant known gas (ft/"R) 

RN = Gas constant, new gas (ft/"R> 

TAU = Torque (in.-lb> 

T2 = Inlet total temperature (OR) 

T2N = Inlet total temperature, new (OR) 

T3 = Exit total temperature (OR> 

T3N = Exit total temperature, new 

UTK = Tip speed, known (ft/sec> 

UTN = Tip speed, new (ft/sec> 

VACR2 = Inlet velocity ratio 

VACR3 = Exit velocity ratio 

VCR2K = Known credit sonic velocity 

VJI = Ideal jet velocity 

V2 = Inlet velocity 

VM3 = Exit merid. velocity 

WK = Weight flow known (lb/sec> 

WN = Weight flow, new gas (lb/sec) 

WEQU = Air standard corrected 

weight flow 

XK = (GAMK - l>/GAMK, known 

XN = (GAMN - l>/GAMN, new 

X2K = (GAMK - 1>/2, known 

X2N = (GAMN - 1112, new 

YK = l/(GAMK - 11, known 

THETA = T2j518.7 

X3 = (GAMN - l>/(GAMN+l> 

10 
APPENDIX C 

BRAYCOMP.BAS PERFORMANCE PREDICTION PROGRAM 

5 REM "THIS IS THE BRAYCOMP.BAS PROGRAM" 

10 INPUT "SCREEN (S), PRINTER (P1, OR FILE (F)? ";SD$ 

15 IF SD$="P" THEN 20 

16 IF SD$="F" THEN 25 

17 GOTO 30 

20 OPEN "LPT1 :" FOR OUTPUT AS #1 :WIDTH "LPT1 :",70:GOTO 35 

25 OPEN "BCOMP001 .REP" FOR OUTPUT AS #1 :GOTO 35 

30 OPEN "SCRN:"FOR OUTPUT AS #1 :WIDTH "SCRN:",80 

35 PRINT "This is the BRAYCOMP.BAS program. This program matches 

36 PRINT "Brayton cycle compressors for different gases. Output 

40 PRINT "is sent to file BCOMPOOl.REP. Names of allowed gases 

45 PRINT "are: AIR,NEON,ARGON,& KRYPTON. He/Xe mixtures may also 

46 PRINT "be used:He/Xe(20.18,39.95 & 83.88) Test data is 

50 PRINT "available for 4.25,5.976,& 6.44 inch diameter compressors 

55 PRINT "Calculations can also be made for the 6.5-inch-diam. 

56 PRINT "CBC Compressor . I' 

60 PRINT "Input (KNOWN) compressor tip diameter (DT1":INPUT DT 

65 PRINT "Input name of gas for which data is known (KG$)":INPUT KG$ 

66 LET PI=3.14159:5=778.16:CN=229.18:G=32.17 

70 IF KG$='IAIRII THEN 1000 

71 IF KG$="ARGON" THEN 1020 

75 IF KG$="HE/XE(39.95>" THEN 1040 

76 IF KG$="NEON" THEN 1060 

80 IF KG$="HE/XE(20.18>" THEN 1080 

85 IF KG$="KRYPTON" THEN 2000 

90 IF KG$="HE/XE(83.88)" THEN 2020 

100 LET 

110 LET 

120 LET 

130 LET 

140 LET 

150 LET 

160 LET 

170 LET 

180 LET 

190 LET 

200 LET 

210 LET 

220 LET 

230 LET 

240 LET 

AM2=PI *(DI '2-DH-2 /4 :AR3=PI*DT*BH 

K2=SQR(GAMK*G/(RK*T21)*AM2:VT2=WK/(K2*P2) 

VTT2=VT2:LET VT2=(WK/(K2*P2) )/((l-X2*VTT2-2)'(YK)> 

DELl=ABS(VTT2-VT2):IF DEL1>.0001 GOTO 120 

RH02=( P2* 144/ (RK*T2 1) * ( ( 1 -X2*VT2-2> '(YK) ) :UTK=DT*NK/CN 

REK=RH02*UTK*DT/(MU2K*l2> :DTI=T2*(PReXK-1 ) 

DTA=DTI/ETAC:TS=T2+DTA 

VM2=144*WK/(RH02*AM2>:PHI=VM2/UTK 

FCW=G* J*CPK* (T5-12) /UTK-2 : LET H=CPK*DTI * J 

FS=FCW-FW 

NS=NK*SQR( WK/Rti02) /( 60* ( (G*"> - .75> 1 

THETA=T2/518.7:LET DEL=P2/14.7:T3=T5 

WEQU=WK*SQR(THETA)/DEL:NKEQU=NK/SQR(THETA) 

K3=SQR(GAMK*G/(RK*T3))*AR3*P2*PRI 

VT3=WK/K3:AT3=SQR(GAMK*G*RK*T3) 

250 LET VTT3=VT3:VT3=SQR( (( (WK/K3>/((1-X2*VTT3^2)-YK> 1-21 

260 LET DEL2=ABS(VTT3-VT3):IF DEL2>.0001 GOTO 250 

270 LET DR2=( PRI /( 1 +(PRI -XK-11 /ETACI 1) *( ( 1 -X2*VT3-2> 

280 LET THETA=T2/518.7:DEL=P2/14.7:T3=T5 

290 LET RH03=(P2*PRI*144/(RK*T3) )*( ( l-X2*VT3-2)^(YK> : DR=RH03/RH02 

+( (FS*UTK/AT3> -2)) 

/( 1 -X2*VT2^2)) -YK 

300 PR1NT:PRINT "Input name of New gas (NG$)": INPUT NG$ 

11 
310 IF NG$="AIR" THEN 5000 

320 IF NG$="ARGON" THEN 5020 

330 IF NG$="HE/XE(39.95>" THEN 5040 

340 IF NG$="ARGON" THEN 5020 

350 IF NG$="HE/XE(83.88>" THEN 6020 

360 LET WN=MU2N*WK/MU2K:K2N=AM2*SQR(GAMN*G/(RN*T2N)):VT2N='~T2 

370 LET PRX=PRI:VT3N=VT3 

380 LET P2NT=WN/(K2N*VT2N*( 1-X2N*VT2Ne2) -YN) 

390 LET UTN=SQR(GAMN*RN/(GAMK*RK>>*UTK*VT2N/VT2 

400 LET NN=UTN*CN/DT 

41 0 LET RH02NT=( P2NT* 144! / (RN*T2N) ) * ( ( 1 -X2N*VT2-N2) ^YN) 

41 5 LET DTAN=FCW*UTN-2/(G*J*CPN> :DTINT=DTAN*ETAC 

420 LET HN=CPN*DTINT*J : RHOZN=WN/ (NS*( 60*( (G*HN) -. 75) ) /NN> '2 

430 LET VT2N=(WN/(K2N*P2NT>>/((l-X2N*VT2N^2)'YN) 

440 LET P2N=RH02N*RN*T2N/((( l-X2N*VT2N'2)-YN>*l44> 

450 LET DEL2N=ABS(P2N-P2NT) 

460 LET VT2NT=(WN/(K2N*PZN)>/((l-X2N*VT2N-2)-YN) 

465 DEL6N=ABS(VT2NT-VT2N) 

470 LET VT2N=VT2NT:IF ABS(DEL6N)>.001 THEN 460 

490 LET VT2N=(WN/(K2N*P2N>)/(( 1-X2N*VT2N-2) 'YN) 

480 IF DEL2N>.001 GOTO 380 

500 LET PRIN=DR* ( ((PRX-XN-1) /ETACI >+1)* (( 1 -X2N*VT2Ne2 1 

/(l-X2N*VT3Ne2))^YN 

505 LET DELZ=ABS(PRIN-PRX) 

510 LET PRX=PRIN:IF DEL2>.0005 GOTO 500 

520 LET PRN=(DTAN*ETAC/T2N+l) -( 1 /XN> 

530 LET VM2N=VT2N*SQR(GAMN*G*RN*T2N>:PHIN=VM2N/UTN 

540 LET NNEQU=NN/SQR(THETA):DTIN=DTAN*ETAC 

550 LET T5N=T2N+DTAN 

560 LET K3N=SQR(GAMN*G/(RN*TSN>)*AR3*P2N*PRIN:FCWN=G*J*CPN 

570 LET AT3N=SQR(GAMN*G*RN*T5N):FSN=FCWN-FW:VTT3N=VT3N 

580 LET VT3N=SQR((((WN/K3N>/((l-X2N*VTT3N-2)-YN))-ZI 

590 LET DEL~N=ABS(VTT~N-VT~N>ZIF DEL3N>.001 GOTO 500 

600 LET DEL4N=ABS(DTINT-DTIN>:IF DEL4N<1! GOTO 620 

610 LET DTINT=DTIN:GOTO 420 

620 LET RH03N=(P2N*PRIN*144/(RN*T5N))*((l-X2N*VT3N-2)-YN) 

630 LET NSN=NN*SQR(WN/RH02N> / (60* ( (G*HN> - .75> ) 

650 LET VT2N=VT2N/(l-DELSN>:GOTO 380 

660 LET REN=RH02N*UTN*DT/(MU2N*12) 

*(T5N-T2N) /UTN-2 

+( (FSN*UTN/AT3NIa2)) 

640 LET DRN=RH03N/RH02N:DEL5N=(DRN-DR>/DRN:IF ABS(DEL5N><.001 THEN 660 

700 PRINT #l,"Compressor Data: Tip Diam.,DT"; FIX(lOOO*DT+.5)/1000; 

710 PRINT #1 ,"Inlet Tip Diam. ,DI";FIX(1000*D1+.5)/1000 

715 PRINT #l,"Inlet Hub Diam.,DH";FIX(1000*DH+.S~/lOOO; 

720 PRINT #1 ,'I, Exi t 6 1 a d e Hei ght , BH" ;FIX( 1000*BH+. 5) / 1000; 

725 PRINT #1 ,"Wi ndage Factor, FW" ;FIX( lOOO*FW+. 5) /lo00 

730 PRINT #l,:PRINT #l,Nl$:PRINT #l,Dl$:PRINT #1,D2$ 

740 PRINT #1 ,:PRINT #1 ,"INPUT DATA" 

750 PRINT #l,"Inlet Pressure,P2";;;FIX(lOO*P2+.5)/100 

755 PRINT #1 ,"Inlet Temp. ,T2"; FIX(T2+.5) 

760 PRINT #1 , "Weight Flow, WK" ;FIX( 1000*WK+. 5) / 1000 

765 PRINT #l,"Pressure Ratio,PR"; FIX(1000*PR+.5)/1000 

770 PRINT #l,"Imp. Pressure Ratio,PRI"; FIX(1000*PRI+.5~/100O 

775 PRINT #l,"Adiabatic Eff.,ETAC"; FIX(1000*ETAC+.5~/1000 

12 
780 PRINT #1 ,"Impeller Eff. ,ETACI"; FIX(100O*ETACI+.5~/1000 

785 PRINT #l,"Rotational Speed,NK";FIX(100000!*NK+.5~/100000! 

790 PRINT #1, :PRINT #1 ,"KNOWN GAS(";KG$;") RESULTS" 

800 PRINT #1 ,"Known Vi scosi ty,MU2K" ; ; ;FIX( 1000*(MU2K*l 0-5)+. 5) / 1000 

810 PRINT #l,"Total Temp. Ratio,T3/T2";FIX(1000*(T5/T2)+.5)/1000 

815 PRINT #l,"Inlet Vel. Ratio,VT2"; FIX(1000*VT2+.5)/1000 

820 PRINT #1 ,"Exit Vel. Ratio,VT3"; FIX(1000*VT3+.5~/100O 

830 PRINT #1 ,"Density Ratio,DR";FIX(1000*DR+.5~/1000 

840 PRINT #1 ,"Known Corr. RPM,NKEQU";FIX(NKEQU+.5) 

845 PRINT #1,"Known Tip Speed,UTK"; FIX(lO*UTK+.S>/lO 

850 PRINT #1,"Compr. Work Factor,FCW";FIX(1000*FCW+.5)/1000 

855 PRINT #l,"Slip Factor,FS";FIX(1000*FS+.5)/1000 

860 PRINT #l,"Inlet Flow Coeff.,PHI";FIX(1000*PHI+.5~/1000 

870 PRINT #1 ,"Specific Speed, NS" ; FIX( 1000*NS+. 5) /lo00 

880 PRINT #1 ,"Known Reynolds No. ,REK"; FIX((REK/10~6~*100+.5)/100 

; 'I E+06" 

881 PRINT #1,:PRINT#l,N2$:PRINT #l,D3$:PRINT #1,D4$ 

882 PRINT #1 , : PRINT#l , N3$ 

890 PRINT #1 ,"Inlet Pressure ,P2N"; ;FIX( 100*P2N+. 5>/100 

895 PRINT #1 ,"Inlet Temp. ,T2N1';FIX(T2N+.5> 

900 PRINT #l,"Weight Flow,WN";FIX(1000*WN+.5~/1000 

905 PRINT #1 ,"Pressure Ratio,PRN" ;FIX( 100*PRN+.5>/100 

910 PRINT #1 ,"Imp. Pressure Ratio,PRIN" ;FIX( 100*PRIN+. 5>/100 

915 PRINT #1 ,"Adiabatic Eff. ,ETAC"; FIX(1000*ETAC+.5~/1000 

920 PRINT #1 ,"Impeller Eff.,ETACI"; FIX(1000*ETACI+.5~/1000 

925 PRINT #1 ,"Rotational Speed,NN"; FIX(NN+.S):PRINT #1 ,:PRINT #1 ,: 

930 PRINT #l,"New Viscosity,MU2N";FIX~lOOO*~MU2N*lO5~+.5~/lOOO;~~E-O5~~ 

935 PRINT #l,"Total Temp. Ratio,T3/T2";FIX(1000*(T5N/T2N)+.5)/1000 

940 PRINT #1,"Inlet Vel. Ratio,VT2N~~;FIX(1000*VT2N+.5)/1000 

945 PRINT #l,"Exit Vel. Ratio,VT3N";FIX(1000*VT3N+.5)/1000 

950 PRINT #l,"Density Ratio,DRN";FIX(1000*DRNt.5~/1000 

955 PRINT #l,"New Corr. RPM,NNEQU";FIX(NNEQU +.5) 

960 PRINT #1 ,"Ti p Speed ,UTN" ;FIX( 10*UTN+. 5>/10 

965 PRINT #l,"New Work Factor,FCWN";FIX(1000*FCWN+.5~/1000 

970 PRINT #1 ,"New S1 ip Factor ,FSN";FIX(1000*FSN+.5)/1000 

975 PRINT #l,"Inlet Flow Coeff.,PHIN";FIX(1000*PHIN+.5)/1000 

980 PRINT #l,"New Specific Speed,NSN";FIX(1000*NSN+.5~/1000 

985 PRINT #1 ,"New Reynolds No. , REN" ;FIX( (REN/106>*100+. 5) / 100;"Et06" 

990 PRINT "CALCULATION COMPLETE" : STOP 

; "E-05" 

1000 LET MK=29:RK=1545/MK:GAMK=l .4:XK=(GAMK-l >/GAMK:CPK=RK/(XK*J) 

1001 LET X2=(GAMK-1>/2:YK=1/(GAMK-l):Nl$="THE KNOWN GAS IS AIR" 

1002 LET Dl$="Mol . Wt.=29.0,R=53.28":D2$="Sp. Heat=.24,Gam=l .4" 

1003 IF ABS(DT-4.25) <=.0001 THEN 2000 

1004 IF ABS(DT-5.976) <=.0001 THEN 2010 

1005 IF ABS(DT-6.44) <=.0001 THEN 2020 

1006 IF ABS(DT-6.5) <=.0001 THEN 2025 

1007 LET MU2K=( .2361+ .002 173*T2-5.75E-07* ( T2 " 2 >+9.17E-11* (T2-3) ) *( 10--5) 

1020 LET MK=39.948:RK=1545/MK:GAMK=1.667:XK=(GAMK-l)/GAMK:CPK=RK/(XK*J) 

1021 LET X2=(GAMK-l)/2:YK=l/(GAMK-l):Nl$="THE KNOWN GAS IS ARGON." 

1008 GOT0 100 

1022 LET D1 $="Mol . Wt . =39.948, R=38.68" : D2$="Sp. Heat=. 124 ,GAM=l .667. I' 

1023 IF ABS(DT-4.25) <=.0001 THEN 2030 

1024 IF ABS(DT-5.976) <=.0001 THEN 2040 

13 
1025 IF ABS(DT-6.44) <=.0001 THEN 2050 

1026 IF ABS(DT-6.5) <=.0001 THEN 2055 

1027 LET MU2K=( .323+.002454*T2-3.53E-07*(T2-2))*(10--5) 

1040 LET MK=39.948:RK=1545/MK:GAMK=1.667:XK=(GAMK-l)/GAMK:CPK=RK/(XK*J) 

1041 LET X2=(GAMK-l>/2:YK=l/(GAMK-l):Nl$="THE KNOWN GAS IS HE/XE(39.95>" 

1043 IF ABS(DT-4.25) <=.0001 THEN 2060 

1028 GOTO 100 

1042 LET D1 $='I Mol . Wt . =39.948, R=38.68" : D2$="Sp. Heat=. 124 ,GAM=1 .667" 

1044 IF ABS(DT-5.976) <=.0001 THEN 2070 

1045 IF ABS(DT-6.44) <=.0001 THEN 2080 

1046 IF ABS(DT-6.5) <=.0001 THEN 2085 

1047 LET MU2K=( .0764+ .003819*T2-1 .479E-06*(T2-2>+5.22E-lO*T2-3 

-8.160001E-14*T2~4~*(10'-5~ 

1048 GOTO 100 

1060 STOP 

1080 STOP 

2000 LET P2=21.64:T2=540:WK=.638:PR=1.71:ETAC=.8:NK=54600! :DI=2.6 

2002 LET DH=1.44:BH=.205:PRI=1.81:ETACI=.895:FW=.039~GOTO 1007 

2010 LET P2=6.41:T2=536:WK=.497:PR=2.09:ETAC=.798:NK=40300! :DI=3.528 

2012 LET DH=1.858:BH =.217:PRI=2.27:ETACI=.896:FW=.O39:GOTO 1007 

2020 STOP 

2022 GOTO 1007 

2025 STOP 

2027 GOTO 1007 

2030 LET P2=20.25:T2=540:WK=.785:PR=1.9:ETAC=.8:NK=52200! :DI=2.6:DH=1.44 

2032 LET BH=.205:PRI=2.03:ETACI=.895:FW=.O39:GOTO 1027 

2040 LET P2=6:12=536:WK=.611:PR=2.38:ETAC=.798:NK=38500! :DI=3.528:DH=1.858 

2042 LET BH=.217:PRI=2.62:ETACI=.896:FW=.O39:GOTO 1027 

2050 LET P2=6!:T2=536:WK=.611:PR=2.3:ETAC=.821:NK=385OO!:DI=3.95:DH=2.19 

2052 LET BH=.31:PRI=2.47:ETACI=.897:FW=.O39:GOTO 1027 

2055 STOP 

2057 GOTO 1027 

2060 STOP 

2062 GOTO 1047 

2070 LET P2=6.85:T2=536:WK=.704:PR=2.42:ETAC=.798:NK=38920! :DI=3.528 

2072 LET DH=1.858~BH=.217~PRI=2.65:ETACI=.896~FW=.O39~GOTO 1047 

2080 LET P2=6.87:T2=536:WK=.704:PR=2.32:ETAC=.821:NK=38800! :DI=3.95:DH=2.19 

2082 LET BH=.31:ETACI=.897:FW=.O39:GOTO 1047 

2085 LET P2=26.4:T2=520:WK=1.87:PR=1.9:ETAC=.842:NK=32OOO:DI=4!:DH=2.28 

2087 LET BH=.351:PRI=2.04:ETACI=.91:FW=.O39:GOTO 1047 

5000 LET MN=29:RN=1545/MN:GAMN=1.4:XN=(GAMN-l)/GAMN:CPN=RN/(XN*J) 

5001 LET X2N =(GAMN-1)/2:YN=l/(GAMN-l):T2N=T2 

5002 LET N2$="THE NEW GAS IS AIR.": D3$="MOl. Wt.=29.O,R=53.28" 

5004 LET MU2N=( .2361+ .002 173*T2 ~ N-5.75E-07* (T2N-2 >+9.17E - 1 1 * (T2N-3 1 ) * ( 10--5> 

5003 LET D4$="Sp. Heat=.24,GAM=l .4.":N3$="PERF. USING AIR." 

5008 GOTO 360 

5020 LET MN=39.948:RN=1545/MN:GAMN=1.667:XN=(GAMN-l)/GAMN:CPN=RN/(XN*J) 

5021 LET X2N=(GAMN-1>/2:YN=l/(GAMN-lI:T2N=T2 

5022 LET N2$= "THE NEW GAS IS ARGON" D3$="MOl . Wt .=39.948, R=38.68" 

5024 LET MU2N=( .323+.002454*T2N-3.53E-O7*(T2N-2))*( 10--5> 

5040 LET MN=39.948:RN=1545/MN:GAMN=1.667:XN=(GAMN-l)/GAMN:CPN=RN/(XN*J) 

5041 LET X2N=(GAMN-l)/2:YN=l/(GAMN-l):T2N=T2 

5023 LET D4$="Sp. Heat=. 124 ,GAM=l .667. 'I : N3$="PERF. USING ARGON. 'I 

5028 GOTO 360 

14 
5042 LET N2$="THE NEW GAS IS HE/XE(39.95>": D3$="MOI. Wt.=39.948,R=38.68Og' 

5044 LET MU2N=( .0764+. 00381 9*T2-1 .479E-06* ( T2-2 )+5.22E-lO*T2 -3-8.160001 E 

5043 LET D4$="Sp. Heat=.124,GAM=1,667.":N3$="PERF. USING HE/XE(39.95>." 

-14*T2'4>*( 10-4) 

5048 GOT0 360 

6000 STOP 

6020 STOP 

15 
APPENDIX D 

LISTING NO. 2 

BRAYTURB.BAS PERFORMANCE PREDICTION PROGAM 

5 REM "THIS IS THE BRAYTURB.BAS PROGRAM'' 

10 INPUT "SCREEN (SI, PRINTER (PI, OR FILE (F)? ";SP$ 

15 IF SP$="P" THEN 30 

20 IF SP$= "F" THEN 35 

25 GOTO 40 

30 OPEN "LPT1:" AS #1 :GOTO 50 

35 OPEN "BTURB001.REP" FOR OUTPUT AS #l:GOTO 50 

40 OPEN "SCRN:"FOR OUTPUT AS #1 

50 PRINT "This is the 6RAYTURB.BAS program. This program matches Brayton 

51 PRINT I' Cycle turbines for different gases." 

70 PRINT "Names of allowed gases are: AIR,NEON,ARGON,& KRYPTON. 

75 PRINT "He/Xe mixtures may also be used:He/Xe(20.18,39.95, & 83-88> 

80 PRINT "Test data is available for 4.59, 4.97, & 6.02 inch d. turbines." 

85 PRINT "Calculations can also be made for the 7.65 in. d. CBC turbine." 

90 PRINT "Input (Known) turbine tip diameter (DT>":INPUT DT 

95 PRINT "Input name of gas for which data is known (KG$)":INPUT KG$ 

60 LET PI=3.14159:J=778.16:CN=229.18:G=32.17 

100 IF KG$="AIR" THEN 1000 

105 IF KG$="ARGON" THEN 1020 

110 IF KG$="HE/XE(39.95)" THEN 1040 

115 IF KG$="NEON" THEN 1050 

120 IF KG$="HE/XE(20.18>" THEN 1060 

125 IF KG$="KRYPTON" THEN 1070 

130 IF KG$="HE/XE(83.88>" THEN 1080 

140 LET AR2=PI*DT*BW 

145 LET AM3=PI*(DE-2-DH -2 1 /4:ANOZ=AR2*COS(ALPH2/57.296> 

150 LET K2=SQR(GAMK*G/(RK*T2)>*ANOZ:VACR2=WK*SQR((GAMK+l)/Z)/(K2*P2) 

155 LET VCR2K=SQR(2*GAMK*G*RK*T2/(GAMK+l)) 

160 LET VACRTZ=VACR2 

165 LET VACR2=SQR( (GAMK+l) /2)*(WK/(K2*P2> 1 /( (l-X3*VACRT2-2) -(YK)) 

175 LET RH02=(P2*144/(RK*T2>>*((l-X3*VACR2^2)-(YK) :LET UTK=DT*NK/CN 

180 LET REK=WK*24/(MU2K*DT>:DTI=T2*(l-l/(PRXK>>:DELHI=CPK*DTI 

185 LET DELH=DELHI*ETAT 

190 LET DTA=DTI*ETAT:T3=T2-DTA 

195 LET V2=144*WK/(RH02*ANOZ) 

200 LET H=DELHItJ:VJI=SQR(2*G*J*DELHI) 

205 LET NU=UTK/VJI 

2 10 LET DEL=P2 / 14.69 : EPSI=( .7396* ( ( (GAMK+ 1 /2 1 - (GAMK/ (GAMK- 1 ) ) /GAMK) 

215 LET WEQU=WK*VCR2K*EPSI/(DEL*lOl8.4):NKEQU=NK*lOl8.4/VCR2K 

220 LET TAU=J*CN*WK*DELH/(NK*2):TAUEQU=TAU*EPSI/DEL 

225 LET K3=SQR(GAMK*G/(RK*T3> l*AM3*P2/PR 

230 LET VACR3=WK*SQR((GAMK+1)/2)/K3 

235 LET VCRT3=VACR3:VACR3=(WK/K3)*SQR((GAMK+1)/2>/((1-X3*VCRT3^2)-YK) 

170 LET DELl=ABS(VACRT2-VACR2):IF DEL1>.0001 GOTO 160 

16 
240 LET DEL2=ABS(VCRT3-VACR3>:IF DEL2>.0001 GOTO 235 

245 LET RHO34 P2*PR* 144/(RK*T3> )*( ( 1 -X3*VACR3-2> -YK) 

250 LET NS=NK*SQR( WK/RH03> / (60* ( (G*H> - .75> > 

255 LET DHEQU=DELH*( 101 8.4/VCR2K> -2: TAUEQU=TAU*EPSI /DEL 

260 LET PREQU=( l-DHEQU/( .24*518.7*ETAT> ) -(-3.5> 

265 LET PRSEQU=(l-DHEQU/(.24*518.7*ETAS>)'(-3.5) 

270 LET DHIEQU=DHEQU/ETAS:VJEQU=SQR(2*G*J*DHIEQU):UTEQU=DT*NKEQU/CN 

275 LET NUEQU=UTEQU/VJEQU 

285 IF NG$=" 'I THEN 7000?290 IF NG$=IIAIRI' THEN 5000 

295 IF NG$=IIARGONII THEN 5020 

300 IF NG$="HE/XE(39.95>" THEN 5040 

305 IF NG$="ARGON" THEN 5020 

310 IF NG$="HE/XE(83.88>" THEN 5060 

315 LET WN=MU2N*WK/MU2K:K2N=ANOZ*SQR(GAMN*G/(RN*T2N>>:VCRT2N=VACR2 

320 LET VCR2N=SQR(2*GAMN*G*RN*T2N/(GAMN+l)> 

330 LET P2N=14.69*WN*VCR2N*EPSIN/(WEQU*lOl8.4> 

335 LET DELHN=DHEQU*(VCR2N/1018.4> -2:DTAN=DELHN/CPN 

337 LET NN=NKEQU*VCR2N/1018.4 

339 LET UTN=DT*NN/CN 

340 LET VACRT2N=VACR2 

345 LET VACR2N=SQR( (GAMNt1>/2)*(WN/(K2N*P2N)> /( (1-X3N*VCRT2N-2> -YN> 

350 LET DELlN=ABS(VCRT2N-VACR2N):VCRT2N=VACR2N 

370 LET PRN=(l-DTAN/(ETAT*T2N>)-(-l /XN> 

375 LET PRSN=( l-DTAN/(ETAS*T2N>) -(-l /XN> 

380 LET DTAN=DELHN/CPN 

385 LET RH02N=(P2N*144! /(RN*T2N) I*( ( 1-X3N*VACR2Na2) -YN) 

390 LET DTIN=DTAN/ETAT:DELHIN=DTIN*CPN 

395 LET T3N=T2N-DTAN:K3N=SQR(GAMN*G/(RN*T3N>>*AM3*P2N/PRN:VCRT3N=VACR3 

400 LET VCRT3N=VACR3N:VACR3N=SQR( (GAMN+1)/2>*(WN/K3N>/( (l-X3N*VCRT3N-2>-YN> 

405 LET DEL3N=ABS(VCRT3N-VACR3N):IF DEL3N>.001 GOTO 400 

410 LET RH03N=( ((P2N/PRN>*144>/(RN*T3N> >*( ( 1-X3N*VACR3Ne2> -YN> 

415 LET HN=CPN*DTIN*J 

420 LET NSN=NN*SQR(WN/RH03N)/(60*((G*HN>- .75>> 

425 LET P2NT=RH02N*RN*T2N/((( l-X3N*VCRT2N-2>-YN>*144) 

430 LET V2N=VCR2N*VACR2N:VJIN=SQR(2*G*J*DELHIN) 

435 LET TAUN=J*CN*WN*DELHN/(NN*2) 

440 LET UTN=DT*NN/CN:NUN=UTN/VJIN 

445 LET REN=WN*24/(MU2N*DT> 

500 PRINT #1 ,"TURBINE ";KG$;"-";NG$;" MATCHING" 

280 PR1NT:PRINT "Input name of New gas (NG$)": INPUT NG$ 

32 5 LET EPS I N= ( .7396* ( ( (GAMN+ 1 > /2 1 - (GAMN/ (GAMN- 1 ) ) > /GAMN 1 

355 IF DELlN>.0001 GOTO 350 

501 PRINT #1 ,"Tip Diam. ,DT";FIX (1000*DT+.5~/1000; 

502 PRINT #l,";Inlet Blade Width,BW,";FIX (lOOO*BW+.5>/1000; 

503 PRINT #1 ,";Stator Angle, ALPH2";ALPH2;";" 

505 PRINT #1 ,"Exit Tip Diameter,DE";FIX (1000*DE+.5)/1000; 

506 PRINT #1 ,";Exit Hub Diam. ,DH";FIX(1000*DH+.5>/1000 

510 PRINT #l,:PRINT #l,Nl$:PRINT #l,Dl$:PRINT #1,D2$ 

515 PRINT #1 ,:PRINT #1 ,"INPUT DATA" 

520 PRINT #1, "Inlet Pressure,P2";FIX(10O*P2+.5>/100 

530 PRINT #1, "Inlet Temperature, T2";FIX(T2+.5) 

535 PRINT #1 , "Weight Flow, WK" ;FIX( 1000*WK+. 5) /lo00 

540 PRINT #1, "Total Pr. Ratio,PR";FIX(1000*PR+.5>/1000 

545 PRINT #1 , "Total / Total Ef f i c . , ETAT" ; FIX( 1 OOO*ETAT+ .5> / 1000 

17 
550 PRINT #1 , "Total /Static Pr. Ratio,PRS";FIX(1000*PRS+.5~/1000 

555 PRINT #l,"Total/Static Effic.,ETAS";FIX(1000*ETAS+.5)/1000 

560 PRINT #1, "Rotor Speed, NK";FIX (100000!*NK+.5)/100000! 

562 PRINT #1 ,:PRINT #1 ,"Known Gas ";KG$;" Results" 

565 PRINT #1, "Inlet Vel. Ratio,VACR2";FIX(1000*VACR2+.5)/1000 

570 PRINT #1 , "Inlet Vel. ,V2";FIX(lO*V2+.5>/10 

575 PRINT #l,"Ideal Jet Vel.,VJI";FIX(VJI+.5) 

580 PRINT #1,"Function,EPSI";FIX(lOOO*EPSI+.5)/1000 

585 PRINT #1, "Exit Cr. velocity,VACR3";FIX(lOOO*VACR3+.5)/lOOO 

590 PRINT #1 , "In1 et Vi scos i ty ,MU2K" ;FIX( 1 OOO* (MU2K* 10-5>+. 5) / 1000; "E-5" 

600 PRINT #1 , "Total Temp. Ratio, T3/T2";FIX(1000*(T3/T2)+.5~/1000 

610 PRINT #l,"Tip SpeedyUTK";FIX(1O*UTK+.5>/10 

615 PRINT #1 , "Specific Work,DELH";FIX(lOO*DELH+.5>/100 

620 PRINT #1, "Blade/Jet Speed Ratio,NU";FIX(1000*NU+.5~/1000 

625 PRINT #1, "Specific Speed=";FIX(1000*NS+.5~/1000 

630 PRINT #1 , "Reynolds No.=" ;FIX( (REK/10-3>* loo+. 5) /loo; "E+3" 

635 PRINT #1, "Torque,TAU";FIX(100*TAU+.5~/100 

640 PRINT #l,:PRINT #l,"Air equivalent (U.S. standard sea level) design"; 

645 PRINT #1 , I' values are as follows:" 

650 PRINT #l,"Equiv. Weight Flow=";FIX(1000*WEQU+.5~/1000 

655 PRINT #1 , "Equiv. Speed=";FIX(NKEQU+.5> 

660 PRINT #l,"Equiv. Tot/Tot.Pr. Ratio,PREQU";FIX(1000*PREQU+.5)/1000 

665 PRINT #1 , I' Equ . B1 ade / Je t Speed Rat i 0, NUEQU" ; FIX( 1000*NUEQU+. 5) / 1 000 

670 PRINT #l,"Equiv. Sp. Work=";FIX (100*DHEQU+.5)/100 

672 PRINT #1, "Equiv. Torque,TAUEQU";FIX(lOO*TAUEQU+.5)/100 

674 PRINT #1 ,"Equlv. Tot/Stat. Pr. Ratio,PRSEQU";FIX( 1000*PRSEQU+.5>/1000 

680 PRINT #1 , : PRINT #1 , N2$ : PRINT #1 , D3$ : PRINT #1 ,049 

682 PRINT #1 , :PRINT #1 ,"PERF. USING ";NG$ 

685 PRINT #l,"Inlet Tot. Pr., P2N";FIX(lOO*P2N+.5>/100 

686 PRINT #1 ,"Inlet Temp. ,T2N1';FIX(T2N+.5> 

687 PRINT #1 ,"Wei ght flow, WN I' ;FIX( 1000*WN+. 5) /lo00 

690 PRINT #l,"New Pressure Ratio,PRN";FIX(100*PRN+.5)/100 

691 PRINT #l,"Total/Total Effic.,ETAT";FIX(1000*ETAT+.5~/1000 

700 PRINT #l,"New Static Pr. Ratio,PRSN";FIX(100*PRSN+.5)/100 

705 PRINT #l,"Total to Static Effic.";FIX(1000*ETAS+.5~/1000 

710 PRINT #1 ,"New Rotational Speed, NN";FIX(NN+.S> 

714 PRINT#l , : 

715 PRINT #1 ,:PRINT #1 ,"New Inlet Vel. Ratio,VACR2N";FIX(lOOO 

*VACR2N+.5>/1000 

720 PRINT #1 ,"Inlet Veloci ty,V2N1';F1X(V2N+.S> 

730 PRINT #l,"New Ideal Jet Vel.,VJIN";FIX(VJIN+.5) 

735 PRINT #l,"New Function,EPSIN";FIX(lOOO*EPSIN+.5~/lOOO 

740 PRINT #l,"New Exit Cr. Vel.,VACR3N";FIX(1000*VACR3N+.5)/1000 

750 PRINT #1 ,"New In1 et Vi scosi ty,MU2N" ;FIX( (1000*MU2N*10-5>+. 5) /1000; "E-5" 

760 PRINT #1 , "Total Temp. Ratio,T3N/T2N";FIX(lOOO*(T3N/T2N)+.5)/1000 

765 PRINT #1 ,"New Tip Speed,UTN";FIX(UTN+.5) 

770 PRINT #1 ,"New Specific Work,DELHN" ;FIX( 100*DELHN+. 5>/100 

775 PRINT #l,"Blade/Jet Speed Ratio,NUN";FIX(1000*NUN+.5)/1000 

780 PRINT #1, "New Specific Speed,NSN";FIX(1000*NSN+.5)/1000 

785 PRINT #1, "New Reynolds No. ,REN" ;FIX( (REN/10~3>*100+.5>/1OO;~~E+3" 

790 PRINT #l,"New Torque,TAUN";FIX(100*TAUN+.5)/100 

7 9 5 P R I N T 'I Ca 1 c u 1 a t i on Com p 1 e t e I' : S TOP 

1000 LET MK=29:RK=l545/MK:GAMK=l .4:XK=(GAMK-l >/GAMK:CPK=RK/(XK*J> 

1001 LET X2=(GAMK-l>/2:YK=l/(GAMK-l):X3=(GAMK-l)/(GAMK+l) 

:Nl$="THE KNOWN GAS IS AIR" 

18 
1002 

1003 

1004 

1005 

1006 

1007 

1008 

1020 

1021 

1022 

1023 

1024 

1025 

1026 

1027 

1028 

1040 

1041 

1042 

1043 

1044 

1045 

1046 

1047 

1048 

1050 

1060 

1070 

1080 

2000 

2002 

2004 

2008 

201 0 

2020 

2022 

2024 

2028 

2030 

2032 

2034 

2038 

2040 

2042 

2044 

2048 

2050 

2052 

LET Dl$="Mol. Wt. = 29.0,R = 53.28,I1:D2$ = "Sp. Heat = .24,GAM = 1.4" 

IF ABS(DT-6.02><=.0001 THEN 2000 

IF ABS(DT-7.65><=.0001 THEN 2010 

IF ABS(DT-4.59><=.0001 THEN 2060 

IF ABS(DT-4.97><=.0001 THEN 3000 

LET MU2K=(. 2361 +. 0021 73*T2-5.75E-07*(T2-2 >+9.17E-11*( T2-3) ) *( 10--5> 

LET MK=39.948:RK=1545/MK:GAMK=1.667:XK=(GAMK-l)/GAMK:CPK=RK/(XK*J) 

:Nl$="THE KNOWN GAS IS ARGON" 

IF ABS(DT-6.02><=.0001 THEN 2020 

IF ABS(DT-7.65><=.0001 THEN 2030 

IF ABS(DT-4.59><=.0001 THEN 2070 

IF ABS(DT-4.97><=.0001 THEN 2090 

LET MU2K=( .323+.002454*T2-3.53E-07*(T2-2))*(10--5> 

LET MK=39.948:RK=1545/MK:GAMK=1.667:XK=(GAMK-l)/GAMK:CPK=RK/(XK*J) 

LET X2=(GAMK-1)/2:YK=l/(GAMK-l):X3=(GAMK-l)/(GAMK+l) 

:Nl$="THE KNOWN GAS IS HE/XE(39.95)" 

IF ABS(DT-6.02><=.0001 THEN 2040 

IF ABS(DT-7.65><=.0001 THEN 2050 

IF ABS(DT-4.59)<=.0001 THEN 2080 

GOTO 140 

LET X2=(GAMK-1)/2:YK=l/(GAMK-l):X3=(GAMK-l)/(GAMKtl) 

LET Dl$="Mol. Wt.=39.948,R=38.68I1:D2$="Sp. Heat=. 124,GAM=1 .667." 

GOTO 140 

LET Dl$="Mol. Wt.=39.948,R=38.68":D2$="Sp. Heat=.124,GAM=1.667." 

PRINT "No 4.97 in. d. data avai1able":STOP 

-8.160001 E-14*T2-4)*(lOa-5> 

GOTO 140 

PRINT "No NEON data avai1able":STOP 

PRINT "No HE/XE(20.18> data avai1able":STOP 

PRINT "No KRYPTON data avai 1able":STOP 

PRINT "No HE/XE(83.88> data avai1able":STOP 

REM "This is AIR/DT = 6.02 data" 

LET MU2K=( .0764+. 0038 1 9*T2-1 .479E-06* (T2 -2) +5.22E-lO*T2-3 

LET P2=13.24:T2 = 1950:WK = .481:PR = 1.5:ETAT = .88:NK = 43653!:DE = 4.294 

LET DH=1.5:DT=6.02:BW=.72:PRS=1.54:ETAS=.824:ALPH2=72 

GOTO 1007 

PRINT "NO DATA AVAILABLE" :STOP 

REM "Thi s i s ARGON/DT=6.02 data" 

LET P2=13.5~T2=1950~WK=.6ll~PR=1.56~ETAT=.88~NK=38500! :DE=4.294 

LET DH=l.S:DT=6.02:BW=.72:PRS=l.613:ETAS=.824:ALPH2=72 

GOTO 1027 

REM "Thi s i s ARGON/DT=7.65 data" 

LET P2=39.61~T2=1810~WK=1.513~PR=1.77~ETAT=.897~NK=OOOO~DE=5.355 

LET DH=3.06:DT=7.65:BW=.64:PRS=1.85:ETAS=.84:ALPH2=72 

GOTO 1027 

REM "This is HE/XE(39.95)/DT=6.02 data" 

LET P2=16.45:T2=1950:WK=.745:PR=l,56:ETAT=.88:NK=38500! :DE=4.294 

LET DH=1.5:DT=6.02:BW=.72:PRS=1.61:ETAS=.824:ALPH2=72 

GOTO 1047 

REM "This is HE/XE(39.95>/DT=7.65 data" 

LET P2=47.9:T2=1810:WK=1.83:PR=1.768:ETAT=.897:NK=32OOO:DE=5.355 

2054 LET DH=3.06:DT=7.65:BW=.64:PRS=1.828:ETAS=.84:ALPH2=72 

19 
2056 LET N2$="THE KNOWN GAS IS HE/XE(39.95)" 

2057 LET D3$="Mol. Wt.=39.948,R=38.68":D4$="Sp. Heat=.124,G 

2058 GOTO 1047 

2060 PRINT"N0 DATA AVA1LABLE:STOP 

2070 REM "This is ARGON/DT=4.59 data" 

M=l .667. I' 

_. . 

2072 LET P2=22.7:T2=1950:WK=.6ll:PR=1.56:ETAT=.86~NK~505OO!~DE=3.264 

2074 LET DH=1.144:DT=4.59:BW=.55:PRS=1.613:ETAS=.8l:ALPH2=72 

2078 GOTO 1027 

2080 REM"This is HE/XE(39.95)/DT=4.59 data" 

2082 LET P2=27.67:T2=1950:WK=.745:PR=1.56:ETAT=.86:NK=5OSOO!:DE=3.264 

2084 LET DH=1.144:DT=4.59:8W=.55:PRS=1.61:ETAS=.8l:ALPH2=72 

2088 GOTO 1047 

2090 REM "This is ARGON/DT=4.97 data. 

2092 LET P2=7! :T2=610:WK=.266:PR=1.75:ETAT=.884:NK=28394:DE=3.46 

2094 LET DH=1.822:DT=4.97:BW=.6:PRS=1.763:ETAS=.875:ALPH2=72.5 

2098 GOTO 1027 

3000 REM "This is Air/DT=4.97 data" 

3002 P2=7.06:T2=610:WK=.216:PR=1.65:ETAT=.884:NK=32194:DE=3.46 

3004 LET DH=1.822:DT=4.97:BW=.6:PRS=1.66:ETAS=.875:ALPH2=72.5 

5000 LET MN=29:RN=1545/MN:GAMN=1.4:XN=(GAMN-l)/GAMN:CPN=RN/(XN*J) 

5001 LET X2N=(GAMN-1)/2:YN=l/(GAMN-l):X3N=(GAMN-l)/(GAMN+l) 

5002 LET N2$= "THE NEW GAS IS AIR":D3$="Mol. 

3008 GOTO 1027 

Wt.=29.OlR=53.28" 

5003 LET D4$="Sp. Heat=.24,GAM=l .4" 

5004 LET T2N=T2- 

5006 LET MU2N=~.2361+.002173*T2N-5.75E-07*~T2N~2~+9.l7E-ll*~T2N~3~~ 

*( 10--5> 

5008 GOTO 31 5 

5020 LET MN=39.948:RN=1545/MN:GAMN=1.667:XN=(GAMN-l)/GAMN:CPN=RN/(XN*J) 

5021 LET X2N=(GAMN-1>/2:YN=l/(GAMN-l):X3N=(GAMN-l)/(GAMN+l) 

5022 LET N2$= "THE NEW GAS IS ARGON" : D3$="Mol . Wt . =39.948, R=38.68" 

5023 LET D4$="Sp. Heat=.124,GAM=1.667l1 

5024 LET T2N=T2 

5026 LET MU2N=( .323+.002454*T2N-3.53E-07*(T2N-2)>*(10--5) 

5028 GOTO 315 

5040 LET MN=39.948:RN=1545/MN:GAMN=1.667:XN=(GAMN-l)/GAMN:CPN=RN/(XN*J) 

5041 LET X2N=(GAMN-1)/2:YN=l/(GAMN-l):X3N=(GAMN-l)/(GAMNtl) 

5042 LET N2$="THE NEW GAS IS HE/XE( 39.95) 'I D3$="Mol . Wt . =39.948, R=38.68" 

5043 LET D4$="Sp. Heat=.124,GAM=1.667" 

5044 LET T2N=T2 

5046 LET MU2N=( .0764+. 0038 1 9*T2-1 .479E-06* ( T2-2) +5.22E-lO*T2-3 

-8.1 60001 E- 1 4*T2 -4) * ( 10-4) 

5048 GOTO 31 5 

5060 STOP 

7000 STOP 

20 
REFERENCES 

1. Effect of Reynolds Number on Overall Performance of a 6-in. Radial Bladed 

Centrifugal Compressor. NASA TN 0-5761. 

2. Reynolds Number Effect On Overall Performance Of A 10.8 cm (4.25 in.) 

Sweptback-Bladed Centrifugal Compressor. NASA TN 0-6640. 

3. Overall Performance in Argon Of A 16.4 cm (6.44 in.) Sweptback-Bladed 

Centrifugal Compressor. NASA TM X-2269. 

4. Experimental Performance Evaluation of a 4.59 in. Radial-Inflow Turbine 

Over a Range of Reynolds Number. 

5. Cold Performance Evaluation of 4.97 in. Radial Inflow Turbine Designed For 

Single - Shaft Brayton Cycle Space - Power System. NASA TN 0-5090. 

6. Cold Performance Evaluation of a 6.02 in. Radial Inflow Turbine Designed 

for a 10 Kilowatt Shaft Output Brayton Cycle Space Power Generation 

System. NASA TN 0-2987. 

21 
TABLE I. - NASA LEWIS COMPRESSOR TEST SUMMARY 

Tip diameter, DT, in. 

Rotational speed, rpm 

Weight flow, lb/sec 

Inlet pressure, lb/in.2 

Pressure ratio 

Inlet temperature, OR 

Efficiency 

Reynolds number/105 

Reference report 

4.25 

52 200 

0.785 

20.25 

1.90 

540 

0.80 

3.03 

TN D-6640 

5.976 

38 500 

0.61 1 

6.00 

2.38 

536 

0.798 

1.30 

TN 0-5761 

6.44 

38 500 

0.61 1 

6.00 

2.30 

536 

0.821 

1.53 

TM X-2269 

6.50 (CBC) 

32 000 

1.87 

26.40 

1.90 

520 

0.842 

5.30 

RI/RD-86-186 

TABLE 11. - 4.25-in.-diam. COMPRESSOR - ARGON/He/Xe MATCHING 

(Refer to Appendix A for units) 

[Tip diameter, DT, 4.25 in.; inlet tip diam. DI, 2.60 in.; inlet hub diameter 

DH, 1.44 in.; exit blade height, BH, 0.205 in.; windage factor, FW, 0.039.1 

Molecular weight 

R 

Specific heat 

GAM 

Inlet pressure 

Inlet temperature 

Weight flow 

Pressure ratio 

Impeller pressre ratio 

Adi abati c efficiency 

Impeller efficiency 

Rotational speed 

Viscosity 

Total temperature ratio 

Inlet velocity ratio 

Exit velocity ratio 

Density ratio 

Corrected rpm 

Tip speed 

Work factor 

Slip factor 

Inlet flow coefficient 

Spec i f i c speed 

Reynolds number 

Known gas: argon 

39.948 

38.680 

0.124 

1.667 

Input data 

P2 = 20.25 

T2 = 540.0 

WK = 0.785 

PR = 1.900 

PRI = 2.030 

ETAC = 0.800 

ETACI = 0.895 

NK = 52 200 

Known gas (argon) 

results 

MU2K = 1.545~105 

T3/T2 = 1.366 

VT2 = 0.213 

VT3 = 0.517 

DR = 1.322 

NKEQU = 51 160 

UTK = 968.0 

FCW = 0.656 

FS = 0.617 

PHI = 0.232 

NS = 0.112 

REK = 3.03~106 

New gas: He/Xe (39.951 

39.948 

38.680 

0.124 

1.667 

Performance using He/Xe 

(39.95) 

P2N = 23.36 

T2N = 540.0 

WN = 0.906 

PRN = 1.900 

PRIN = 2.030 

ETAC = 0.800 

ETACI = 0.895 

NN = 52 200 

New results 

MU2N = 1.78~10-5 

T3/T2 = 1.366 

VT2N = 0.213 

VT3N = 0.517 

DRN = 1.322 

NNEQU = 51 160 

UTN = 968 

FCWN = 0.656 

FSN = 0.617 

PHIN = 0.232 

NSN.= 0.112 

REN = 3.03~106 

22 
TABLE 111. - 5.976-in.-diam. COMPRESSOR - ARGON/He/Xe MATCHING 

(Refer to Appendix A for units) 

[Tip diameter, DT, 5.976 in.; inlet tip diameter DI, 3.528 in.; hub diameter 

DH, 1.858 in.; exit blade height, BH, 0.217; windage factor, FW, 0.039.1 

39.948 

38.68 

0.124 

1.667 

Input data 

Mol e c u 1 a r we i g h t 

R 

Specific heat 

GAM 

39.948 

38.680 

0.124 

1.667 

Performance using He/Xe I(39.95) 

P2 = 6.000 

T2 = 536.0 

WK = 0.611 

PR = 2.380 

PRI = 2.620 

ETAC = 0.798 

ETACI = 0.896 

NK = 38 500 

Known gas (argon) 

results 

MU2K = 1.537~10-5 

T3/T2 = 1.520 

VT2 = 0.296 

VT3 = 0.702 

DR = 1.377 

NKEQU = 37 874 

UTK = 1003.9 

FCW = 0.859 

FS = 0.820 

PHI = 0.311 

NS = 0.105 

REK = 1.30~106 

Inlet pressure 

Inlet temperature 

Weight flow 

Pressure ratio 

Impeller pressure ratio 

Adiabatic efficiency 

Impeller efficiency 

Rotational speed 

P2N = 6.850 

T2N = 536.0 

WN = 0.704 

PRN = 2.420 

PRIN = 2.650 

ETAC = 0.798 

ETACI = 0.896 

NN = 38 920 

New results 

MU2N = 1.77~10-5 

T3/T2 = 1.531 

VT2N = 0.300 

VT3N = 0.707 

DRN = 1.377 

NNEQU = 38 287 

UTN = 1014.9 

FCWN = 0.859 

FSN = 0.820 

PHIN = 0.311 

NSN = 0.105 

REN = 1 .3Ox1O6 

1 

Vi scos i ty 

Total temperature ratio 

Inlet velocity ratio 

Exit velocity ratio 

Density ratio 

Corrected rpm 

Tip speed 

Work factor 

Slip factor 

Inlet flow coefficient 

Specific speed 

Reynolds number 

Known gas: argon 1 New gas: He/Xe (39.95) I 

23 
TABLE IV. - 6.44-in.-diam. COMPRESSOR - ARGON/He/Xe MATCHING 

(Refer to Appendix A for units) 

[Tip diameter, DT, 6.440 in.; inlet tip diameter DI, 3.950 in.; hub diameter 

DH, 2.190 in.; exit blade height, BH, 0.310; windage factor, FW, 0.039.1 

Molecular weight 

R 

Specific heat 

GAM 

Inlet pressure 

Inlet temperature 

Weight flow 

Pressure ratio 

Impeller pressure ratio 

Adiabatic efficiency 

Impeller efficiency 

Rotational Speed 

___ ~~ ~ 

Vi scos i ty 

Total temperture ratio 

Inlet velocity ratio 

Exit velocity ratio 

Density ratio 

Corrected rpm 

Tip speed 

Work factor 

Slip factor 

Inlet flow coefficient 

Specific speed 

Reynolds number 

Known gas: argon 

39.948 

38.68 

0.124 

1.667 

Input data 

P2 = 6.000 

T2 = 536.0 

WK = 0.611 

PR = 2.300 

PRI = 2.470 

ETAC = 0.821 

ETACI = 0.897 

NK = 38 500 

Known gas (argon) 

results 

MU2K = 1.537~10-5 

T3/T2 = 1.482 

VT2 = 0.243 

VT3 = 0.577 

DR = 1.440 

NKEQU = 37 874 

UTK = 1081.9 

FCW = 0.686 

FS = 0.647 

PHI = 0.237 

NS = 0.108 

REK = 1.53~10~ 

New gas: He/Xe (39.95) 

39.948 

38.680 

0.124 

1.667 

Performance using He/Xe 

(39.95) 

P2N = 6.87 

T2N = 536.0 

WN = 0.704 

PRN = 2.320 

PRIN = 2.490 

ETAC = 0.821 

ETACI = 0.897 

NN = 38 787 

New results 

MU2N = 1.77~10-5 

T3/T2 = 1.489 

VT2N = 0.245 

VT3N = 0.748 

DRN = 1.440 

NNEQU = 38 156 

UTN = 1089.9 

FCWN = 0.686 

FSN = 0.647 

PHIN = 0.237 

NSN = 0.108 

REN = 1 .53x106 

24 
TABLE V. - CBC COMPRESSOR - HeIXe ARGON MATCHING 

[Tip diameter, DT, 6.500 in.; inlet tip diameter DI, 4.00 in.; hub diameter 

DH, 2.280 in.; exit blade height, BH, 0.351; windage factor, FW, 0.039.1 

(Refer to Appendix A for units) 

Molecular weight 

R 

Specific heat 

GAM 

Inlet pressure 

Inlet temperature 

Weight flow 

Pressure ratio 

Impeller pressure ratio 

Adiabatic efficiency 

Impeller efficiency 

Rotational Speed 

Vi scos i ty 

Total temperture ratio 

Inlet velocity ratio 

Exit velocity ratio 

Density ratio 

Corrected rpm 

Tip speed 

Work factor 

Slip factor 

Inlet flow coefficient 

Specific speed 

Reynolds number 

Known gas: argon 

(39.95) ~~ ~~ ~ 

39.948 

38.680 

0.124 

1.667 

Input data 

P2 = 26.40 

T2 = 520.0 

PR = 1.900 

PRI = 2.040 

ETAC = 0.842 

ETACI = 0.910 

WK = 1 .a70 

NK = 32 000 

Known gas (CBC(He1Xe)) 

results 

MU2K = 1.73~10-5 

T3lT2 = 1.348 

VT2 = .164 

VT3 = .500 

DR = 1.346 

NKEQU = 31.960 

UTK = 907.6 

FCW = .683 

FS = .644 

PHI = .188 

NS = .094 

REK = 5.30~106 

New gas: HeIXe 

39.948 

0.124 

1.667 

38.680 

Performance using argon 

P2N = 21 .97 

T2N = 520.0 

WN = 1.626 

PRN = 2.000 

PRIN = 2.110 

ETACN = 0.842 

ETACIN = 0.910 

NN = 38 463 

New results 

MU2N = 1.50~10-5 

VT2N = .171 

VT3N = .517 

DRN = 1.347 

NNEQU = 33 421 

UTN = 949.1 

FSN = .644 

NSN = .094 

REN = 5.30~10~ 

T3lT2 = 1.380 

FCWN = .6a3 

PHIN = 188 

25 
TABLE VI. - CALCULATED EFFECT OF COMPRESSOR 

REYNOLDS NUMBER 

Compressor diameter DT, in. 

Adiabatic efficiency, ETAC 

Loss factor 1 - ETAC 

Reynol ds number/ 1 06 

REK/S. 36 

Reynolds ratio to 0.2 

Corrected loss factor 

Predicted CBC efficiency 

Mean values of three 

4.25 

0.79 

0.21 

3.03 

0.572 

0.894 

0.179 

0.821 

5.976 

0.798 

0.202 

1.30 

0.245 

0.755 

0.153 

0.847 

0.843 

0.821 

0.179 

0.289 

0.780 

0.140 

0.860 

TABLE VII. - NASA LEWIS TURBINE TEST SUMMARY 

Tip diameter, DT, in. 

Rotational speed, rpm 

Weight flow, lb/sec 

Inlet pressure, lb/in.2 

Pressure ratio 

Inlet temperature, OR 

Efficiency 

Reynolds number/103 

Reference report 

4.59 

50 500 

0.611 

22.70 

1.56 

1950 

0.86 

84.83 

TN D-3835 

4.97 

28 394 

0.266 

7.00 

1.75 

610 

0.884 

76.07 

TN D-5090 

6.02 

38 500 

0.611 

13.5 

1.56 

1950 

0.88 

64.68 

TN D-2987 

7.65 

32 000 

1.83 

47.9 

1.768 

1810 

0.897 

131.59 

RI/RD-86-186 

26 
TABLE VIII. - 4.59-in.-diam. TURBINE - ARGON-He/Xe (39.95) MATCHING 

(Refer to Appendix B for units) 

[Tip diamter, DT, 4.59 in.; inlet blade width, BW, 0.55 in.; stator angle, ALPH2, 

72"; exit tip diameter, DE, 3.264 in.; exit hub diameter, DH, 1.144.1 

Molecular weight 

R 

Spec i f i c heat 

GAM 

Inlet pressure 

Inlet temperature 

Weight flow 

Pressure ratio 

Totaljtotal efficiency 

Totaljstatic pressure ratio 

Totaljstatic efficiency 

Rotational speed 

Inlet velocity ratio 

Inlet velocity 

Ideal jet velocity 

Function 

Exit cr. velocity 

Inlet viscosity 

Total temperature ratio 

Tip speed 

Specific work 

Blade/jet speed ratio 

Speci f i c speed 

Reynolds number 

Torque 

Known gas: argon 

39.948 

38.68 

0.124 

1.667 

Input data 

P2 = 22.7 

T2 = 1950 

WK = 0.611 

PR = 1.56 

ETAT = 0.86 

PRS = 1.613 

ETAS = 0.81 

NK = 50 500 

Known gas (argon) 

results 

VACR2 = 0.531 

V2 = 924.1 

VJI = 1406 

EPSI = 0.911 

VACR3 = 0.235 

T3/T2 = 0.86 

MU2K = 3.766~10-5 

UTK = 1011.4 

DELH = 33.95 

NU = 0.719 

NS = 0.076 

RE = 84.83~103 

TAU = 36.63 

New gas: He/Xe (39.95) 

39.948 

38.68 

0.124 

1.667 

Performance using He/Xe 

(39.95) 

P2N = 27.67 

T2N = 1950 

WN = 0.745 

PRN = 1.56 

ETAT = 0.86 

PRSN = 1.61 

ETAS = 0.81 

NN = 50 500 

New results 

VACR2N = 0.531 

V2N = 924 

VJIN = 1406 

EPSIN = 0.911 

VACR3N = 0.235 

MU2N = 4.59~10-5 

T3N/T2N = 2.86 

UTN = 1011 

DELHN = 33.95 

NUN = 0.719 

NSN = 0.118 

REN = 84.83~10~ 

TAUN = 44.65 

Air equivalent (U.S. Standard sea level) design values 

~~____~~~ ~~ ~~ ~ 

Equivalent weight flow ........................ 0.616 

Equivalent speed ........................... 29 531 

Equivalent totalltotal pressure ratio; PREQU ............. 1.494 

Equivalent blade/jet speed ratio, NUEQU ............... 0.698 

Equivalent specific work ....................... 11.61 

Equivalent torque, TAUEQU ...................... 21.59 

Equivalent total/static pressure ratio, PRSEQU ........... 1.534 

27 
TABLE IX. - 4.97-in.-diameter TURBINE - ARGON-He/Xe (39.95) MATCHING 

(Refer to Appendix B for units) 

[Tip diameter DT 4.97 inlet blade width, BW, 0.6; stator angle, ALPH2 72.5; exit 

tip diameter, DE 3.46; exit hub diameter, DH 1.822.1 

Molecular weight 

R 

Specific heat 

GAM 

Inlet pressure 

Inlet temperature 

Weight flow 

Pressure ratio 

Total/total efficiency 

Total/static pressure ratio 

Total/static efficiency 

Rotational speed 

Inlet velocity ratio 

Inlet velocity 

Ideal jet velocity 

Function 

Exit cr. velocity 

Inlet viscosity 

Total temperature ratio 

Tip speed 

Specific work 

Bladeljet speed ratio 

Specific speed 

Reynolds number 

Torque 

~_____~ 

Known gas: argon 

39.948 

38.68 

0.124 

1.667 

Input data 

P2 = 7 

T2 = 610 

WK = 0.266 

PR = 1.75 

ETAT = 0.884 

PRS = 1.763 

ETAS = 0.875 

NK = 28 394 

Known gas (argon) 

results 

VACR2 = 0.342 

V2 = 332.7 

VJI = 872 

EPSI = 0.911 

VACR3 = 0.219 

T3lT2 = 0.823 

UTK = 615.8 

DELH = 13.44 

NU = 0.706 

NS = 0.053 

TAU = 11.23 

MU2K = 1.689~10-5 

RE = 76.07~103 

39.948 

38.68 

0.124 

1.667 

Performance using He/Xe 

( 39.95) 

P2N = 8.140001 

T2N = 610 

WN = 0.309 

PRN = 1.75 

ETAT = 0.884 

PRSN = 1.76 

ETAS = 0.875 

NN = 28 394 

New results 

~ ~~~~~ 

VACRZN = 0.342 

V2N = 333 

VJIN = 872 

EPSIN = 0.911 

VACR3N = 0.219 

T3NlT2N = 0.823 

UTN = 616 

DELHN = 13.44 

NUN = 0.706 

NSN = 0.093 

REN = 76.06~103 

TAUN = 13.05 

MU2N = 1.963~10-5 

Air equivalent (U.S. Standard sea level) design values 

Equivalent weight flow ........................ 0.486 

Equivalent speed ........................... 29 687 

Equivalent total/total pressure ratio; PREQU ............. 1.651 

Equivalent blade/jet speed ratio, NUEQU ............... 0.702 

Equivalent specific work ....................... 14.69 

Equivalent torque, TAUEQU ...................... 21.46 

Equivalent total/static pressure ratio, PRSEQU ........... 1.66 

28 
TABLE X. - 6.02-in.-diam. TURBINE - ARGON-He/Xe (39.95) MATCHING 

(Refer to Appendix B for units) 

[Tip diameter, DT, 6.02 in.; inlet tip diameter DT, 6.02 in.; inlet exit blade height, 

BW, 0.72 in.; stator angle, ALPH2 72; exit tip diameter, DE 4.294; exit hub 

diameter., DH 1.5.1 

Molecular weight 

R 

Speci f i c heat 

GAM 

Inlet pressure 

Inlet temperature 

Weight flow 

Pressure ratio 

Total/total efficiency 

Totallstatic pressure ratio 

Total /static effi ciency 

Rotational speed 

Inlet velocity ratio 

Inlet velocity 

Ideal jet velocity 

Function 

Exit cr. velocity 

Inlet viscosity 

Total temperature ratio 

Tip speed 

Speci f i c work 

Bladeljet speed ratio 

Specific speed 

Reynolds number 

Torque 

Known gas: argon 

39.948 

38.680 

0.124 

1.667 

Input data 

P2 = 13.5 

T2 = 1950 

WK = 0.611 

PR = 1.56 

ETAT = 0.88 

PRS = 1.613 

ETAS = 0.824 

NK = 38 500 

Known gas (argon) 

results 

VACR2 = 0.5170001 

V2 = 899.7 

VJI = 1406 

EPSI = 0.911 

VACR3 = 0.227 

T3/T2 = 0.857 

MU2K = 3.766~10-5 

UTK = 1011.3 

NU = 0.719 

NS = 0.075 

TAU = 49.17 

DELH = 34.74 

RE = 64.68~103 

New gas: He/Xe (39.95) 

39.948 

38.680 

0.124 

1.667 

Performance using He/Xe 

(39.95) 

P2N = 16.45 

T2N = 1950 

WN = 0.745 

PRN = 1.56 

ETAT = 0.88 

PRSN = 1.61 

ETAS = 0.824 

NN = 38 500 

New results 

VACRN = 0.517 

V2N = 900 

VJIN = 1406 

EPSIN = 0.911 

VACR3N = 0.277 

T3N/T2N = 0.857 

UTN = 1011 

DEL" = 34.74 

NUN = 0.719 

NSN = 0.116 

TAUN = 59.93 

MU2N = 4.59~10-5 

REN = 64.68~103 

Air equivalent (U.S. Standard sea level) design values 

Equivalent weight flow ........................ 0.616 

Equivalent speed ........................... 29 531 

Equivalent total/total pressure ratio; PREQU ............. 1.494 

Equivalent blade/jet speed ratio, NUEQU ............... 0.698 

Equivalent specific work ....................... 11.61 

Equivalent torque, TAUEQU ...................... 21.59 

Equivalent total/static pressure ratio, PRSEQU ........... 1.534 

29 
TABLE XI. - CBC TURBINE - He/Xe (39.95) - ARGON MATCHING 

(Refer to Appendix B for units) 

I [Tip diameter, DT 7.65; inlet blade width, BW, .64; stator angle, ALPH2 72; exit 

Tip diameter, DE 5.355; Exit Hub diameter, DH 3.06.1 

~~ 

Molecular weight 

R 

Specific heat 

GAM 

Inlet pressure 

Inlet temperature 

Weight flow 

Pressure ratio 

Total/total efficiency 

Total/static pressure ratio 

Total/static efficiency 

Rotational speed 

Inlet velocity ratio 

Inlet velocity 

Ideal jet velocity 

Function 

Exit cr. velocity 

Inlet vi scosi ty 

Total temperature ratio 

Tip speed 

Spec i f i c work 

Bladeljet speed ratio 

Speci f i c speed 

Reynolds number 

Torque 

Known gas: He/Xe 

(39.95) 

39.948 

38.680 

0.124 

1.667 

Input data 

P2 = 47.9 

T2 = 1810 

WK = 1.83 

PR = 1.768 

ETAT = 0.897 

PRS = 1.828 

ETAS = 0.84 

NK = 32 000 

Known gas He/Xe (39.95) 

results 

VACR2 = 0.352 

V2 = 589.8 

VJI = 1515 

EPSI = 0.911 

VACR3 = 0.17 

T3/T2 = 0.817 

UTK = 1.068.2 

DELH = 41.12 

NU = 0.705 

NS = 0.045 

RE = 131.59~103 

TAU = 209.67 

MU2K = 4.363~10-5 

New gas: argon 

39.948 

38.680 

0.124 

1.667 

Performance using argon 

P2N = 39.61 

T2N = 1810 

WN = 1.513 

PRN = 1.77 

ETAT = 0.897 

PRSN = 1.85 

ETAS = 0.84 

NN = 32 000 

New results 

New results 

VACR2N = 0.352 

V2N = 590 

VJIN = 1515 

EPSIN = 0.911 

VACR3N = 0.17 

T3N/T2N = 0.817 

UTN = 1068 

DELHN = 41.12 

NUN = 0.705 

NSN = 0.79 

TAUN = 173.4 

MU2N = 3.608~10-5 

REN = 131.59~103 

Air equivalent (U.S. Standard sea level) design values 

Equivalent weight flow ........................ .842 

Equivalent speed ........................... 19 423 

Equivalent total/total pressure ratio; PREQU ............. 1.666 

Equivalent blade/jet speed ratio, NUEQU ............... 0.682 

Equivalent specific work ....................... 15.15 

Equivalent torque, TAUEQU ...................... 58.57 

Equivalent total/static pressure ratio, PRSEQU ........... 1.729 

30 
60.7 kW 

0 

TABLE XII. - CALCULATED EFFECT OF TURBINE 

REYNOLDS NUMBER 

Tip diameter, DT, in. 

Adiabatic efficiency, ETAK 

Loss factor (1 - ETAK) 

Reynolds number11 03 

REK/131.59~103 

Reynolds ratio to 0.2 power 

Corrected loss factor 

Predicted CBC efficiency 

4.59 

0.86 

0.14 

84.83 

0.645 

0.91 6 

0.133 

0.867 

4.97 

0.884 

0.116 

76.07 

0.578 

0.896 

0.109 

0.891 

6.02 

0.88 

0.12 

64.68 

0.492 

0.868 

0.110 

0.890 

0.883 1 Mean value of three 

0.351 In. 4 0.640 I".+ t1 

ROTOR SPEED I 36 OOO rpm 

1 

RECUPERATOR 4 

€10.94 RADIATOR 

c:3 

91.39 kW 

Figure 2. - CBC system schematiC. 

31 
National Aeronautics and 

Space Administration 

1. Report No. 

NASA CR- 182263 

Report Documentation Page 

2. Government Accession No. 

17. Key Words (Suggested by Author@)) 

Solar Dynamic Power System 

Brayton cycle 

Space Station Freedom power system 

I '. Author(s) 

Robert L. Cummings 

18. Distribution Statement 

Unclassified - Unlimited 

Subject Category 20 

,- 

19. Security Classif. (of this report) 

Unclassified 

9. Performing Organization Name and Address 

20. Security Classif. (of this page) 21. No of pages 22. Price' 

Unclassified I 30 I A03 

Robert L. Cummings, Consultant 

2778 Avon Lake Road 

Litchfield, Ohio 44253 

12. Sponsoring Agency Name and Address 

National Aeronautics and Space Administration 

Lewis Research Center 

Cleveland, Ohio 44135-3191 

15. Supplementary Notes 

3. Recipient's Catalog No. 

5. Report Date 

August 1989 

6. Performing Organization Code 

8. Performing Organization Report No. 

None (E-4657) 

10. Work Unit No. 

474-52- 10 

11. Contract or Grant No. 

C-22 187-M 

13. Type of Report and Period Covered 

Contractor Report 

Final 

14. Sponsoring Agency Code 

Project Manager, Rodger J. Slutz, Solar Dynamic Power and Propulsion Office, NASA Lewis Research Center. 

16. Abstract 

The methods which have been used by the NASA Lewis Research Center for predicting Brayton Cycle 

compressor and turbine performance for different gases and flow rates are described. These methods were 

developed by NASA Lewis during the early days of Brayton cycle component development and they can now be 

applied to the task of predicting the performance of the CBC Space Station Freedom power system. Computer 

programs are given for performing these calculations and data from previous NASA Lewis Brayton Compressor 

and Turbine tests is used to make accurate estimates of the compressor and turbine performance for the CBC 

power system. Results of these calculations are also given in following sections of this report. This work has 

been sponsored by NASA in order to obtain an independent evaluation of the performance of the CBC power 

system. In general, these calculations confirm that the CBC Brayton Cycle contractor has made realistic 

compressor and turbine performance estimates. 

'For sale by the National Technical Information Service. Springfield, Virginia 221 61 NASA FORM 1626 OCT 86