bluuebunny/crossref_metadata_2025 huggingface dataset:
Dust Removal Concepts for Pressurized Fluidized Bed Systems
Authors: Boericke R. R. , Moore W. E.
Published: April 2015

Improved high-temperature (1700°F, 925°C) dust removal concepts are being developed for pressurized fluidized bed combined cycle power generation. Recent results on cyclones, electrocyclones, an acoustic agglomerator, a ceramic bag filter, and an electrostatic granular bed filter are reviewed. The development status of each device is described, and the relative merits of each concept are discussed. System designs for employing each of the dust removal concepts in a 650 MWe PFB reference plant are presented in order to illustrate the application of the devices, and approximate economic comparisons are made for this application.
Development and Performance of the Wedge-Type Low Specific Speed Compressor Wheel
Authors: Rusak V.
Published: April 2015

Low flow, low specific speed compressor stages are known to have inherently low performance level. Their low performance is attributed to a number of factors such as: high internal friction, disk friction, and leakage losses per unit mass flow. Comparative studies of design and performance indicated that it was possible to improve performance of the low specific speed compressor stages through the use of more favorable flow passage cross sections in the impellers. Use of wedge-shaped blades makes it possible to form such impeller flow passages. A major development program, started in early 1960’s, led to the emergency of the wedge-type compressor wheel as the wheel for low flow, low specific speed applications. The wheel is capable of operating in flow ranges previously designated for reciprocating compressors with an excellent operating range and good efficiency.
Effect of Impeller Extended Shrouds on Centrifugal Compressor Performance as a Function of Specific Speed
Authors: Sapiro L.
Published: April 2015

Centrifugal compressors for gas compression applications usually employ low-pressure ratio, backward-swept impellers with vaneless diffusers. To increase the compressor flow range and speed, impeller blades are occasionally trimmed, resulting in an extended shroud configuration. The effect of extended front and back impeller shrouds on the performance of centrifugal compressors with vaneless diffusers, and the variation of this effect as a function of specific speed, is thus of concern and is the subject of this paper. An investigation was carried out on two backward-swept shrouded impellers of common blade tip and inducer hub diameters, but different inducer tip diameters (corresponding to low and high specific speeds), with the front and back shrouds extending 20 percent above the blade’s outside diameter.
Engine Experience of Turbine Rotor Blade Materials and Coatings
Authors: Davis F. N. , Grinnell C. E.
Published: April 2015

Engine experience must be the final arbiter of the most suitable materials and coatings to minimize turbine corrosion. Facts and examples obtained on Rolls-Royce industrial and marine gas turbines are presented. Rig tests provide useful advance information by filtering out unsatisfactory materials and coatings before fixing engine standard for service trials. However, for definitive answers, most rigs are limited in one form or another. Running results show that different engine types under similar environmental conditions give different rates of corrosion. Cooling configuration has highlighted sulphidation in two or more forms and has defined their positions on the hardware. Extended cyclic running, under aggressive conditions, with various material and coating combinations gives results which suggest the need for two layer coating systems.
Heat Transfer Measurements of a Transonic Nozzle Guide Vane
Authors: Litchfield M. R. , Norton R. J. G.
Published: April 2015

The heat transfer and aerodynamic characteristics of a turbine nozzle guide vane with a supersonic exit velocity have been measured in a transient cascade facility. The vane possesses a convergent-divergent passage, and this, together with a low trailing edge wedge angle, is seen to control the supersonic flow efficiently at design conditions. Heat transfer measurements have been taken on both suction and pressure surfaces. On the suction surface, transition is marked by a rapid increase in heat transfer, whereas on the pressure surface a slow increase in heat transfer indicates the gradual onset of turbulence. The measurements also indicate possible relaminarisation of the suction surface boundary layer at the impingement of the trailing edge shock. Predictions are presented of aerodynamic flow, using an inviscid time-marching calculation, and heat transfer, using a differential method applied to the vane surface.
An Advanced Helicopter Engine Control System
Authors: Saunders A. F.
Published: April 2015

This paper describes the design and development of a full authority Digital Engine Control and intelligent cockpit Command Box by Dowty and Smiths Industries Controls Limited (DSIC) under a Ministry of Defence and Private Venture demonstrator program. The aims of this program are to: (1) demonstrate the recent and continuing improvements in IC technology and allied computing power; (2) employ control laws more relevant to electronic control, thus absolving the hydromechanical unit from precise fuel metering; (3) improve, by a quantum leap, the methods of monitoring engine/system performance. This control system has undergone successful engine running on a Rolls-Royce GEM, and will shortly be tested, in prototype form, in a Lynx.
The Influence of Engine Characteristics on Patrol Aircraft Life Cycle Cost Optimization
Authors: Schuetz A. J.
Published: April 2015

A conceptual design study has been conducted for an all-new, land-based patrol aircraft for the U.S. Navy. The selected propulsion system was a conceptual high-speed turboprop. An antisubmarine warfare mission was chosen for the design flight profile. Probable peacetime utilization was postulated so that the engine duty cycle could be estimated. Aircraft designs were optimized for minimum takeoff gross weight (TOGW) and for minimum life cycle cost (LCC). It was shown that the aircraft performance requirements and design constraints bound the optimization process so tightly that the same point design is obtained for both TOGW and LCC criteria. The contribution of the engine costs to the overall life cycle costs was examined. The sensitivity of the aircraft optimization to the engine characteristics — specific fuel consumption (SFC), length, diameter, and cost — was analyzed. It was determined that SFC is the most significant engine characteristic.
Cycle Considerations for Tactical Fighters in the Early 1990’s
Authors: Snyder H. D.
Published: April 2015

The requirements for tactical fighter aircraft in the early nineties will call for improved maneuverability from current fighters, as well as shorter takeoff and landing distances, reduced radar cross-sections and IR signatures, and supersonic persistence. Also, the cost of procurement, operation and maintenance of the engine (LCC) will be a significant parameter in determining the type and performance of the next fighter engine. Each of the above requirements has an effect on the engine cycle to be chosen for the next fighter engine. The sum of these effects should result in a specific engine cycle which best answers all of the aircraft needs, but the effects of these requirements tend toward diverse cycles. This paper addresses these issues and presents a comparison of cycles that meet the anticipated requirements for tactical fighter aircraft in the early nineties. The paper also compares the usage of such aircraft in peacetime training to the design mission in combat.
Evaluation of Shale Oil as a Utility Gas Turbine Fuel
Authors: Sederquist R. A. , Frese J. , McVey J. , Knauf C. L. , Schreiber H.
Published: April 2015

The work described in this paper was conducted under an Electric Power Research Institute (EPRI) Contract RP1691-2, “Evaluation of Shale Oil Residual as a Utility Gas Turbine Fuel.” An FT4A-9 engine was run at Long Island Lighting Company (LILCO), and a selected single-can combustor from the LILCO engine was run at United Technologies on No. 2 petroleum distillate fuel and hydrotreated Paraho shale oil residual, with and without water injection. The use of hot water injection was successfully demonstrated, with reduced NOx emissions and low smoke on both fuels. The EPA NOx limit of 125 ppm for fuels containing 0.25 percent nitrogen or greater was close to being met at 18.5-MW engine power with shale oil residual at a water-to-fuel mass ratio of 0.79.
Solutions of the Three-Dimensional Navier-Stokes Equations in Non-Orthogonal Coordinates to Calculate the Flow in a Log Spiral Impeller
Authors: Swanson B. W.
Published: April 2015

A modification of Moore’s (12) method has been developed for solving the three-dimensional Navier Stokes equations to calculate the flow in a log spiral impeller. A complete mathematical development of this method is presented. The parabolic finite-difference marching code used to make the calculations is an extensive revision of a CATHY3 code obtained from D. B. Spalding. Calculations are made for Vr, Vθ and Vz on a non-orthogonal grid that is ideally suited for impellers with back-swept blades. An inviscid solution is in good agreement with the elliptic solution and validates the computational procedure. The method is applied to calculate the viscous three-dimensional flow in a log spiral impeller.
A Prediction Scheme for the Decay of a Turbomachine Blade Wake
Authors: Kool P. , Hirsch Ch.
Published: April 2015

The effect of a steamwise pressure gradient on the decay of a skewed turbomachinery wake is considered. These pressure gradients are generated by the overall radial equilibrium and by the blade boundary layer separation mechanism at the blade trailing edge. The existence of a separation bubble near this trailing edge is shown to exist and gives rise to a pressure rise in a free stagnation point. The ensuing downstream streamwise pressure gradient influences the decay rate of the wake and the transverse pressure gradient influences the momentum thickness. The streamwise velocity defect can be accurately predicted by taking this pressure gradient into account if a profile shape is assumed and with an eddy viscosity concept. The velocity defect of the axial and tangential velocity profiles can be derived from the streamwise velocity profile parameters.
Material and Process Impact on Aircraft Engine Designs of the 1990’s
Authors: Sprague R. A.
Published: April 2015

For at least the next decade, as in the recent past, the materials and process area will assume a major role in the advancement of the propulsion gas turbine industry. The selection of promising material and process technologies, with highest payoff at lowest technical and financial risk, is a major challenge. Technology development programs undertaken in the laboratory are selected, based on design needs, compatibility with payoffs in specific and generic applications, and facilities requirements. Advanced materials and process technology efforts for exploitation include directional superalloys for turbine airfoils, clean superalloy blisk/disk materials, gas path seals for clearance control, thermal barrier coatings for airfoils and hybrid structures, composite materials, and rapidly solidified plasma deposited structures. These developments will contribute significantly to the major thrusts of performance improvement, weight reduction, reliability and life extension, and reduced initial ownership cost.
Aerodynamic Damping Measurements in a Transonic Compressor
Authors: Crawley E. F.
Published: April 2015

A method has been developed and demonstrated for the direct measurement of aerodynamic damping in a transonic compressor. The method is based on the inverse solution of the structural dynamic equations of motion of the blade-disk system. The equations are solved inversely to determine the forces acting on the system. If the structural dynamic equations are transformed to multiblade or modal coordinates, the damping can be measured for blade-disk modes, and related to a reduced frequency and interblade phase angle. This method of damping determination was demonstrated using a specially instrumented version of the MIT Transonic Compressor run in the MIT Blowdown Compressor Test Facility. No regions of aeroelastic instability were found. In runs at the operating point, the rotor was aerodynamically excited by a controlled two-per-revolution fixed upstream disturbance. The disturbance was sharply terminated midway through the test. Analysis of the data in terms of multiblade modes led to a direct measurement of aerodynamic damping for three interblade phase angles.
Comparison of Two and Three Dimensional Flow Computations With Laser Anemometer Measurements in a Transonic Compressor Rotor
Authors: Chima R. V. , Strazisar A. J.
Published: April 2015

Two and three-dimensional inviscid solutions for the flow within a transonic axial compressor rotor at design speed are compared to laser anemometer measurements at maximum flow and near stall operating points. Computational details of the two-dimensional axisymmetric stream function solution and the three-dimensional full Euler solution are described. Upstream of rotor, the two-dimensional and three-dimensional solutions for radial distribution of relative Mach number and total pressure agree well with the data. Within the bow wave system and the blade row, the axisymmetric two-dimensional solution shows only qualitative agreement with the data.
Nonlinear Analysis of Rotor-Bearing Systems Using Component Mode Synthesis
Authors: Nelson H. D. , Meacham W. L. , Fleming D. P. , Kascak A. F.
Published: April 2015

The method of component mode synthesis is developed to determine the forced response of nonlinear, multishaft, rotor-bearing systems. The formulation allows for simulation of system response due to blade loss, distributed unbalance, base shock, maneuver loads, and specified fixed frame forces. The motion of each rotating component of the system is described by superposing constraint modes associated with boundary coordinates and constrained precessional modes associated with internal coordinates. The precessional modes are truncated for each component and the reduced component equations are assembled with the nonlinear supports and interconnections to form a set of nonlinear system equations of reduced order. These equations are then numerically integrated to obtain the system response. A computer program, which is presently restricted to single shaft systems, has been written and results are presented for transient system response associated with blade loss dynamics with squeeze film dampers, and with interference rubs.
Gas Turbine Application to U.S. Naval Ship Propulsion
Authors: Brady E. F.
Published: April 2015

With introduction of the Spruance Class Destroyers, gas turbines have been used to power both destroyers and frigates. However, to achieve maximum crusing range, high efficiency propulsion systems are required. The scope of this paper is limited to a basic description of propulsion plant configurations, using gas turbines as prime movers. These systems serve as candidates for U.S. Navy ship propulsion. Comparisons are limited to fuel loading, because of its impact on ship design. Although annual fuel consumption is a more accurate measure of fuel efficiency, it requires a specific ship design. This is beyond the scope of this paper. Of the systems considered, the maximum reduction in required fuel loading (for a specific cruising range) was 20%. To achieve optimum efficiency, cross-connect ability (for a two propeller shaft system) is essential. Potential cross-connect methods include mechanical, electrical and steam features. The first two are described in this paper.
Damage Tolerant Design of Turbine Engine Disks
Authors: Cook C. H. , Spaeth C. E. , Hunter D. T. , Hill R. J.
Published: April 2015

This paper describes a USAF sponsored effort to develop, apply, test, and evaluate Pratt & Whitney’s Damage Tolerant Design System for cold-section gas turbine engine disks. The design system includes a Damage Tolerance Specification proposed for new USAF engine programs, material characterization for crack-growth behavior, design procedures, and analytical life prediction methodology for consideration of large flaws. To evaluate and refine the design system, a current engine fan disk was redesigned to operate safely for a specified time after the occurrence of 0.030-inch (0.76 mm) surface length fatigue cracks. The redesigned disk was tested to failure while monitoring crack growth and correlating observed measurements with analytical prediction. Test results were used to refine the design system. Current work involves extending Damage Tolerant Design capability to hot-section powder-metallurgy disks. The impact of these efforts is twofold; current designs will benefit from improved life prediction capability in applying Retirement-for-Cause philosophy, and future designs can take advantage of the Life-Cycle-Cost benefit of designing for damage tolerance.
A Method for Determining the Main Requirements of Outlet Gas Temperature Profile of Marine Gas Turbine Combustors
Authors: Chian-ti Tang
Published: April 2015

Taking account of the marine gas turbine operation features, the author has chosen the hot corrosion peak temperature of materials as the guide vane material limiting temperature while evaluating the overall temperature distribution factor. Along with the blade cooling effectiveness a safety margin factor has been introduced during its evaluation. The gas temperature distribution along blade height is assumed to satisfy the condition that approximately equal safety factor in respect of strength prevails along blade height. Once the gas radial temperature profile becomes known, the radial temperature distribution factor can be readily determined.
Conversion of Centrifugal Compress Performance Curves Considering Non-Similar Flow Conditions
Authors: Fister W. , Kotzur J.
Published: April 2015

Thermodynamic performance testing of centrifugal compressor cannot always be implemented at the same conditions on which the rating of the machine was based. To permit them to be compared to the rated values, the test values must therefore be converted to the respective suction data, gas properties and speeds. Conversion methods applied today which assume similar or approximately similar flow conditions for testing and rating, specify in various instance too narrow limits for this. A new conversion method based on few measurement values was developed to consider the influence exerted by the most important parameters, such as Mach and Reynolds numbers, etc. on energy transfer in the stage and on flow losses. Performance curves converted according to the new method, are compared to actually measured values.
Deposit Formation in Hydrocarbon Fuels
Authors: Roback R. , Szetela E. J. , Spadaccini L. J.
Published: April 2015

A high pressure fuel coking test apparatus was designed and developed and was used to evaluate thermal decomposition (coking) limits and carbon deposition rates in heated copper tubes for two hydrocarbon fuels, RP-1 and commercial-grade propane. Tests were also conducted using JP-7 and chemically-pure propane as being representative of more refined cuts of the baseline fuels. A parametric evaluation of fuel thermal stability was performed at pressures of 136 atm to 340 atm, bulk fuel velocities in the range 6–30 m/s and tube wall temperatures in the range 422–811 K. In addition, the effect of the inside wall material on deposit formation was evaluated in selected tests which were conducted using nickel-plated tubes. The results of the tests indicated that substantial deposit formation occurs with RP-1 fuel at wall temperatures between 600 and 800 K, with peak deposit formation occurring near 700 K. No improvements were obtained when deoxygenated JP-7 fuel was substituted for RP-1. The carbon deposition rates for the propane fuels were generally higher than those obtained for either of the kerosene fuels at any given wall temperature. Finally, plating the inside wall of the tubes with nickel was found to significantly reduce carbon deposition rates for RP-1 fuel.
The Influence of Trailing Edge Ejection on the Base Pressure in Transonic Turbine Cascades
Authors: Sieverding C. H.
Published: April 2015

This paper summarizes the results of base pressure studies on transonic turbine blades in presence of an ejection of coolant flow from a slot in the trailing edge. The first part of the paper reports on tests carried out on a enlarged model of the overhang section of a typical transonic cascade. This model provides valuable information about the detailed trailing edge pressure distribution and points to an asymmetric evolution of the base pressure on both sides of the slot in presence of a bleed. The second part of the paper presents experimental results from cascade tests covering an outlet Mach number range from M2, is = 0.5 to 1.35. These experiments underline the importance of the coolant flow impact on the base pressure and confirm the asymmetry of the base pressure with respect to the cooling slot. Tests with different coolant flow gases point to the significance of a proper simulation of the density ratio between coolant flow and main flow.
Improved Vane-Island Diffusers at High Swirl
Authors: Jiang Tong , Yang Tah-teh
Published: April 2015

The results of an experimental investigation of the performance of vane-island diffusers at high swirl [λ = 9] are presented in this paper. These results show the advantage of the 14-vane versus several 8-vane configurations. Four sets of 14 straight vanes are used in this study as compared to five sets of eight vanes in a previous investigation. The 14-vane configuration results in a 40 percent reduction in pressure loss coefficient below that obtained with eight vane configurations. The lowest loss coefficient obtained in the present investigation is achieved when the vane leading edge is at a radius approximately equal to 1.2 times the diffuser inlet radius. The experimental results are presented in the form of pressure rise versus radial location along the diffuser, diffuser effectiveness versus flow coefficient, and minimum pressure loss coefficient versus flow coefficient.
Comprehensive Analysis of an Axial Compressor Test With Adjustable Guide Vanes
Authors: Chun-lin Chang , Chin-hua Kuo , She-li Sha
Published: April 2015

An adjustment testing has been successfully conducted on a 12-stage single rotor axial compressor formed by adding two stages to the front of the original ten-stage subsonic compressor. Tests were carried out for five rows of adjustable guide vanes, based on the relationship of setting angle variation with speed. The test results were compared with the case when fixed geometry configuration was used. With the compressor operating under fixed geometry version there existed in medium speed zone distinct “dual value characteristics, “for which detailed measurements were taken and possible implications discussed. Tests have shown that the use of adjustable guide vanes for improving medium and low speed performance is fully justified.
Prototype Testing Methods Variable Geometry Industrial Gas Turbines
Authors: McQuiggan G.
Published: April 2015

This paper describes the prototype engine testing methods used to determine the performance and integrity of a new industrial gas turbine in the 20-MW to 30-MW range (CW352). This gas turbine is very flexible in that it is designed with the following features: (i) Variable compressor inlet guide vanes; (ii) 15-, 16- or 17-stage compressor alternatives; (iii) Variable power turbine vanes; (iv) Regenerative or simple cycle mode of operation.
Carbon Formation by the Pyrolysis of Gas Turbine Fuels in Preflame Regions of Gas Turbine Combustors
Authors: Hurley C. D.
Published: April 2015

A series of experiments have been carried out to investigate the formation of carbon from the pyrolysis of gas turbine fuels, in both the gas and liquid phases, over the temperature range 573–1300 K. Two fuels were examined, a kerosine and a diesel, spanning the range of current and possible future aviation fuels. It was found that only gas phase pyrolysis could account for the formation of carbon and that there was no difference in the carbon forming tendencies of kerosine and diesel. The kinetics of the reaction were determined, making it possible to predict the amount of decomposition of the fuels at temperatures up to those typical of preflame regions of combustors.
Casing Treatments on a Supersonic Diffuser for High Pressure Ratio Centrifugal Compressors
Authors: Ribaud Y. , Avram P.
Published: April 2015

Centrifugal compressors with high pressure ratios from 7 to 10 often have a very slow mass flow margin. Suitable casing treatments, including large openings at the diffuser throat connected to annular plenums, greatly increase the reduced mass flow range of the diffuser during supersonic inlet operation. In the region of reduced mass flow variation, the reduction of the diffuser flow is associated with a drop of the effectiveness. The use of a backswept centrifugal rotor allows the experiment to overcome this penalty.
Correlations of Soot Formation in Turbojet Engines and in Laboratory Flames
Authors: Gill R. J. , Olson D. B. , Calcote H. F.
Published: April 2015

Smoke related performance of both jet engine and research combustors has been correlated with several fuel properties. The smoke related data included: smoke number, liner temperature rise, and radiation flux to the combustor wall; fuel parameters included: percent hydrogen, percent aromatic, percent polycyclic aromatic, smoke point, and the threshold soot index, TSI. The research combustor results correlated best with the threshold sooting index. While some correlations with engine performance were excellent, no single fuel property was generally useful in evaluating smoke related performance, mainly because of insufficient data on the fuels tested in the jet engine programs, e.g., percent aromatics specifies a class of fuels which span > 50% of the possible range of sooting tendencies. It is, however, demonstrated that fuel composition plays a dominant role in determining smoke related engine parameters. It is recommended that fuels used for engine testing programs be chemically analyzed in greater detail or be made available for laboratory measurements of soot thresholds and soot yields until a sufficient data base is available to establish a laboratory technique of predicting relative smoke related performance of fuels in jet engines.
Parametric Study of Turbine Blade Platform Friction Damping Using the Lumped Parameter Analysis
Authors: Dominic Robert J.
Published: April 2015

A parametric study of turbine blade platform friction damping has been performed using the lumped parameter analysis. The hardware configuration used in the analysis is the first stage turbine of the High Pressure Fuel Turbopump of the Space Shuttle Main Engine. The analysis procedure, developed over the last few years by A. Muszynska, now of Bently Nevada Corporation, and D.I.G. Jones, of AFWAL/MLLN, solves the nonlinear equations of motion of a turbine blade acted on by a platform friction damper by an iterative matrix method. The parametric study considers the effects on the blade deflection response of variations in: the coefficient of friction; the normal force on the friction surface interface; the blade hysteretic damping; the blade to blade phase angle of the harmonic forcing function; and the amplitude of the forcing function. The results of the study are applicable to any blade-damper system similar to the one used in the study. [Work sponsored by Marshall Space Flight Center of NASA.]
Performance Comparison Between Transpiration Air Cooled Turbine 3000°F (1649°C) Stator Vanes and Solid Uncooled Vanes
Authors: Manning George B. , Moskowitz Seymour
Published: April 2015

Testing was conducted to compare the aerodynamic performance of a turbine vane using transpiration air-cooling capable of operation at 3000°F (1649°C) gas temperature with a vane of identical profile with no cooling provisions to determine the effect of cooling on vane kinetic energy efficiency and loss coefficient. The test configuration was a 10-vane section of full scale first stage turbine stator annulus designed for 1.6 pressure ratio, cooling air flow equal to 6.1 percent of primary flow, 3000°F (1649°C) turbine inlet temperature and primary-to-coolant temperature ratio of 2.7. To enable comparison with other investigations, tests were conducted at three pressure ratios from 1.4 to 1.6, three coolant flows from 75 to 120 percent of design, and three primary-to-coolant temperature ratios from 2.70 to 1.15.

Efficiency, loss coefficient and flow capacity test results were in good agreement with predicted values for both the transpiration air cooled and uncooled vanes. The testing demonstrated that it is necessary to conduct test evaluations of transpiration air-cooled components at or near design coolant-to-gas stream temperature ratio in order to achieve correct results.
Taipower Tunghsiao Stag Combined Cycle Power Plant
Authors: Tomlinson Leroy O. , Timmerman David C.
Published: April 2015

Units 1 and 2 in the Tiawan Electric Power Co. (Taipower) are General Electric STAG 307E combined cycle systems with rated output of 570 MW. These combined cycle generation systems include high technology gas turbines, an unfired steam system with steam generation at two pressures and computer based control systems. The net plant thermal efficiency at the rating point is 45.3% on distillate oil and 44.8% on residual oil. Currently one of the six gas turbines is operating on residual oil and five are operating on distillate. When the residual oil conversion is complete, these will be the World’s most efficient residual oil fired power generation units. A description of the distinguishing features, construction and early operating history are presented.
Simulation of Surge Margin Changes due to Heat Transfer Effects in Gas Turbine Transients
Authors: Larjola Jaakko
Published: April 2015

The subject of this study is the simulation of low-frequency transients (such as acceleration, deceleration) of different open cycle gas turbine types. Special attention is paid to the correct calculation of the effects of heat transfer between process gas and solid structure. Correcting equations for these effects are developed and the transient properties of each component are then evolved from the static ones with these equations. It is shown that the heat transfer effects alter significantly the surge margin of the compressor. Simulation model includes intercooler and recuperation. The programming language is CSMP.
Development of the F110-GE-100 Engine
Authors: Coalson Michael S.
Published: April 2015

The F110-GE-100 engine is now in the qualification or “production verification” phase of development. From a technical standpoint it represents the first USAF fighter engine which has been developed without extreme emphasis on either high thrust or light weight. Rather, since its inception the program emphasis has been on a balance of durability, operability and performance. For this reason alone, this paper should be interest to those whose business centers on fighter engine development.
Experimental Studies of Deposition by Electrostatic Charge on Turbine Blades
Authors: Raj R. , Moskowitz S.
Published: April 2015

Experimental tests were conducted to determine the electrical charge related deposition on turbine blades in a hot gas stream. Transpiration air cooled, water cooled, and uncooled turbine specimens were tested.

The results indicate that the gas stream charge is proportional to fluid particle velocity and particle concentration. The ionic concentration of the gas increases with increase in gas temperature in the range of 1000°F (537°C) to 2200°F (1200°C). The deposition was found to be less for the transpiration air cooled test sample at 1300°F (704°C) metal temperature and the excessively water cooled test sample at 350°F (176°C) than for the uncooled test samples. There is some evidence to indicate that by using electrostatic means, a reduction in deposition on turbine blades operating on a contaminated stream resulting from coal firing, may be possible.
Operating Experience With a 13,000 SHP, Two Stage, Fluid Cat-Cracker Power Recovery Expander
Authors: Linden David H. , Mathers William G.
Published: April 2015

An internal inspection of the expander after 16,000 hours of operation confirmed the successful operation of Ingersoll-Rand’s first two stage, high temperature, FCC expander. This paper discusses the construction and operation of the unit, designed for 1300°F (704°C) dirty gas environment and presents the inspection results of critical components.
Gas Turbines for Coal-Fired Turbocharged PFBC Boiler Power Plants
Authors: Wenglarz Richard , Drenker Steven
Published: April 2015

A coal-fired turbocharged boiler using fluidized bed combustion at high pressure would be more compact than a pulverized coal fired boiler. The smaller boiler size could permit the utility industry to adopt efficient modular construction methods now widely used in other industries.

A commercial turbocharger of the capacity needed to run a 250 MWe power plant doe not exist; commercial gas turbines of the correct capacity exist, but they are not matched to this cycle’s gas temperature of less than 538°C (1000°F). In order to avoid impeding the development of the technology, it will probably be desirable to use existing machines to the maximum extent possible. This paper explores the advantages and disadvantages of applying either standard gas turbines or modified standard gas turbines to the turbocharged boiler.
Behavior of Coal Ash and Alkali Matter in a Coal-Fired Gas Turbine System
Authors: Ahluwalia R. K. , Im K. H. , Chuang C. F. , Geyer H. K. , O’Brien T. J. , Berry G. F. , Myles K. M. , Petrick M.
Published: April 2015

The behavior of coal ash and corrosive alkali species in a gas turbine fueled by an ultra-clean coal water mixture (UCCWM) is investigated. A thermochemical equilibrium analysis is first conducted to study the effect of coal cleaning on the extent of vaporization of ash constituents. It is found that for a selected bituminous coal, cleaned up to 10% of the initial ash content, the amount of Ca, Mg, Si and Al vaporized is independent of coal cleaning and that of Na, K and Fe directly proportional to the degree of coal cleaning. In order to study the fate of the vaporized constituents, a gas-to-particle conversion (condensation) model is formulated. The aerosol processes of homogeneous nucleation, heterogeneous nucleation, particle agglomeration, particle deposition, as well as direct vapor deposition on boundary surfaces are included in the formulation. The aerosol formation calculations are driven by the gas phase equilibrium chemistry of twelve elements and twenty seven gaseous species. The model is partially validated by comparison against available laboratory data on ash nucleation in a laminar flow furnace. Application of the model to UCCWM gas turbine system indicates that the characteristic condensation time of sodium and potassium sulfates is much smaller than the residence time in gas turbine, that in spite of the presence of numerous nucleated ash particles the alkali sulfates undergo self-nucleation, and that thermophoresis and Brownian motion are expected to be the primary mechanisms of sulfate deposition on turbine blades.
The PW1120: A High Performance, Low Risk F100 Derivative
Authors: Zipkin M. A.
Published: April 2015

The PW1120 engine is a turbojet derivative of the F100 turbofan engine that has accumulated more than 1.9 million flight hours in F-15 and F-16 fighters throughout the free world. Pratt & Whitney Aircraft (P&WA) initiated design and development of the PW1120 as a company sponsored military engine development program in 1980 and the program has progressed on schedule through more than 1,000 hours of development engine testing and Flight Clearance Testing. Performance goals and operational characteristics of the PW1120 engine at both sea level and altitude simulated flight conditions have been successfully demonstrated. This paper addresses the design characteristics of the PW1120 engine and its commonality with the F100 engine, and discusses those commonality benefits in terms of reliability, maintainability, safety, and logistics support. Development program plans, achievements, and applications for the PW1120 engine are also discussed. Flight Clearance of the PW1120 will be completed during the second half of 1984 with full qualification in late 1986. Production will start in early 1987. Initial application is in the Israel Air Force’s new indigenous fighter, the Lavi.
A New Diffuser Mapping Technique
Authors: Japikse D.
Published: April 2015

A rigorous derivation of the K = Cpi − Cp diffuser recovery and loss equation is presented and the critical assumptions to yield this simplified relationship are critiqued. Confirmation of the equation is achieved using precise laboratory data and a new diffuser loss-map is presented which facilitates engineering diffuser design work, even when a Kline-map is unavailable. Numerous application examples for turbomachinery analysis are given.
Relative Flow Structure at Exit From an Axial Compressor Rotor in Rotating Stall
Authors: Cheng R. , Ekerol H. , Railly J. W.
Published: April 2015

The phase-lock-averaging (PLA) technique is used in association with a traverse gear mounted on an axial compressor rotor to explore the flow field at exit from the rotor during rotating stall. The technique requires the use of a trigger hot-wire anemometer also mounted on the rotor to ensure the proper location of the stall cell in relation to the measurement probe. The probe consists of a three-wire non-orthogonal array which may be traversed radially and peripherally over a complete blade passage. By a systematic adjustment of the probe orientation angle, the presence of reverse flow is detected. A mathematical procedure for the determination of the magnitude and direction of the flow vector is presented. On the basis of a large collection of phase-locked data it is demonstrated that the leading and trailing edges of the cell travel at a non-uniform rate and in such a way as to vary cyclically in peripheral extent with a period related to the blade passing fequency. The peripheral distribution of the flow vector at successive instants of relative time is also produced from the data collection and the evolution of the stall cell structure is presented.
Extima-2, an Explicit Time-Marching Method to Calculate Transonic Turbomachinery Cascade Flow
Authors: Hoffmann W.
Published: April 2015

An explicit time-marching procedure to calculate transonic turbine or compressor cascade flow has been developed. The integral unsteady Euler equations are approximated by a conservative finite volume discretization using split space operators in a predictor-corrector scheme. Results are obtained with the physical flow field geometry. At solid walls streamline differentiation is used to update boundary values in a nonorthogonal grid which is automatically generated and sectionally aligned to the boundary. Near the leading and trailing edges and at captured shock waves the computation is stabilized by a switched numerical Shuman-type filter. To minimize computing time the code is vector-optimized for use on a CRAY-1/S computer. In this paper particular details of the calculation procedure are discussed and sample calculations are presented.
Cooling and Insulating Problems in a High Temperature Helium Test Facility
Authors: Haselbacher H. , Sponholz H.-J.
Published: April 2015

For non-nuclear testing of circuit components of high-temperature gas-cooled reactors with large helium turbines, two basic types of test facilities can be employed: (a) a classical closed-cycle gas turbine plant with fossil-fired or electric heater or (b) a test circuit that requires no separate heater but whose energy comes from the motor-driven compressor of the turbomachine. The second type is the subject of this paper, which begins with the general considerations and a description of such a plant. The main part, which includes experimental results, reports on the thermal performance of two main components of the test facility, namely the turbomachine and the hot gas duct.
The Behaviour of the Normal Fluctuation Terms in the Case of Attached or Detached Turbulent Boundary Layers
Authors: Gerolymos G. A. , Kallas Y. N. , Papailiou K. D.
Published: April 2015

The turbulent normal fluctuation terms have been found from measurements to be very important, when approaching separation, inside the separated flow region, as well as, in the region where a shock wave interacts with a turbulent boundary layer. In the present work correlations are developped on the basis of available experimental results, which relate the normal fluctuation terms, appearing in integral formulations for turbulent boundary layer calculation methods, to mean flow quantities. These correlations are valid, as far as compressible attached or separated turbulent boundary layers are concerned, as well as in the case of a shock wave/turbulent boundary layer interaction which leads to boundary layer separation. Furthermore, correlations are developed for the maxima of the velocity fluctuation terms.
Ten Years of Gas Turbine Propulsion in Ships of the Royal Netherlands Navy
Authors: de Kanter J. C. F. , Lutje-Schipholt R. M. , Crommelin G. A. K.
Published: April 2015

The paper highlights design intentions and actual achievements. Hidden bonuses as well as set backs are looked at from technical, operational and budgetarial angles.

As the RN1N is actually in the process of designing and building a so called M-frigate of 3000+ tonnes, a true frigate of the nineties, views of both past and future are presented to the gas turbine world.

Marinised gas turbines have matured considerably in the recent past, but of even greater importance is the fact that naval personnel have matured towards handling gas turbines.

The next decade will therefore see gas turbines in ships, not as some strange high performance “black boxes”, but as the relatively simple, high performance hardware side of the man-machine-symbiosis.

The unique and highly valued qualities of “marinised” aircraft engines will continue to be recognised. But since ships must have a high degree of sustainability during long months of arduous duty, ships carry engineers and self maintenance will play an ever increasing role.
Progress in Net Shape Fabrication of Alpha SIC Turbine Components
Authors: Sweeting T. B. , Frechette F. J. , MacBeth J. W.
Published: April 2015

An update of the status of ceramic component development of the AGT Programs is presented. Activity on AGTO Program focussed on the following: successful transition from the prototype to engine configuration rotor, investigation of alternate rotor molding techniques, and completion of scroll assemblies. Progress on the Garrett AGT Program was highlighted by the introduction of plastic molding and extrusion to parts which were previously fabricated by slip casting and isopressing respectively.
Experimental Studies on Chemical Reactivity and Dimensional Growth in Machining of Titanium Alloys
Authors: Subhas B. K. , Katti R. A.
Published: April 2015

Machining of aero-gas turbine components made of titanium alloys, using different combination of tools, cutting fluids and machining parameters revealed two important characteristics namely, chemical reactivity and dimensional growth. The former is pronounced when machined with carbide tools using Sulphur based cutting oils. The reactivity was not noticeable when machined either with CBN or ceremet tools, contrary to the reports in the literature. This mechanism of chemical reaction has been studied including the development of microcracks at 400°F. The other phenomenon of dimensional growth is also anlysed in detail and machining parameters to reduce this growth are arrived at. The heat treatment is also envisaged to help in depriving of this detrimental dimensional growth by relieving the machining stresses. Also the scope for further research in this area is clearly defined.
Gas Turbine Systems Designed for Coal Water Slurries
Authors: Giramonti A. J. , Robson F. L.
Published: April 2015

Numerous attempts have been made during the past two decades to develop advanced power generation systems which could burn coal or coal-derived fuels both economically and in an environmentally acceptable manner. Although much valuable technology has been derived from these programs, commercially viable power generation alternatives have not yet appeared. One prospective way to expedite the commercialization of advanced coal-fired power systems is to meld the latest gas turbine technology with the emerging technology for producing slurries of water and ultra clean coal. This paper describes a DOE-sponsored program to identify the most attractive gas turbine power system that can operate on slurry fuels. The approach is to use slurries produced from finely ground (<10 microns) coal powder from which most of the ash and sulfur has been removed. The gas turbines will incorporate a rich-burn, quick-quench combustor to minimize conversion of fuel-bound nitrogen to NOx, advanced single crystal alloys with improved hot corrosion resistance and strength, advanced metallic and ceramic coatings with improved erosion and corrosion resistance, and more effective hot section cooling. Two different power plant configurations are covered: a large (nominally 400 MW) combined cycle plant designed for base load applications; and a small (nominally 12 MW) simple-cycle plant designed for peaking, industrial, and cogeneration applications.
Boundary-Layer Transition Regions on Turbine Blade Suction Surfaces
Authors: Roberts G. , Brown A.
Published: April 2015

This paper describes the results of an experimental investigation into extended boundary-layer transition regions on suction surfaces of four sets of turbine blades in a cascade rig. A transition model is proposed which is tested with some success in a modified version of STAN5, a boundary-layer computer programme.
IEA Grimethorpe 2 × 2M PFBC Facility: Turbine Materials Testing in a Cascade Loop
Authors: Minchener A. J. , Mainhardt P. J. , Mountford R. A. , Erbe G. , Anderson J. S. , McCarron R. L.
Published: April 2015

The Grimethorpe pressurised fluidised bed combustor (PFBC) facility of the International Energy Agency is equipped with an off-gas loop in which gas turbine blades are being exposed to assess the potential for erosion, corrosion, or deposition in a PFBC gas turbine.

The flue gas from the PFBC is passed through four stages of cyclones before entering the cascade test section. Depending on operating conditions, the loop passes between 5.0 and 6.4 kg/sec of gas, which allows aerofoils of about the same size as the General Electric MS 1002 turbine blading to be tested.

The cascade contains four stages of nine blades each, as well as three erosion targets. The first three stages are impulse blades and experience a gas velocity in the range 200 to 230 m/sec, while the fourth stage of reaction aerofoils accelerates the gas to between 300 and 400 m/sec before it passes over the erosion targets. Both uncooled (700–850°C) and cooled (500–650°C) blades are used.

Results from initial running of the cascade loop have indicated a dust loading to the cascade of the order of 100 ppm, with median particle sizes in the range of 1 to 2 microns, and an average alkali level (K plus Na) of 1.1 ppm. The blades exhibited the aerodynamically-expected pattern of behaviour, and the results are generally considered encouraging. The continuing overall test programme design is discussed.