bluuebunny/crossref_metadata_2025 huggingface dataset:
Acquisition of F-100(3) High Pressure Compressor Entrance Profiles
Authors: Rabe D. C. , Copenhaver W. W. , Perry M. S.
Published: April 2015

A transportable automatic data acquisition system to obtain high pressure compressor entrance profiles in an F-100 Series 3 gas turbine engine is described. The system was developed, assembled, and tested at Wright-Patterson Air Force Base and transported to a remote location for implementation in a sea level engine test. Acquisition of data was controlled through a Hewlett Packard Model 9825T desktop calculator, preprogrammed to display airflow data in engineering units during the test. Entrance profiles of total and static pressure, temperature, and flow angle for two axial locations are presented. A wedge probe sensing element was positioned at 12 radial locations by remote traversing mechanisms to obtain these profiles. For a total pressure range of 18 to 46 psia (0.13 to 0.32 MPa), acquisition uncertainties in static and total pressure were reduced to below ± percent of measured values by optimizing data system component uncertainties.
A Theoretical Investigation of an Overhung Flexible Rotor Mounted on Uncentralized Squeeze-Film Damper Bearings and Flexible Supports
Authors: Cookson R. A. , Feng Xin-Hai
Published: April 2015

Previous investigations have shown that the uncentralized type of squeeze-film damper is an effective means of reducing the transmission of unbalance forces into the supporting structure. In this theoretical study a more complex model, which includes an overhung “fan” disc and a noncentral “turbine” disc, has been employed. This model represents the conventional gas turbine somewhat closer than does the previously studied single disc system. This investigation has shown that it is possible to minimize the force transmitted into the surrounding structure by a careful selection of squeeze-film damper characteristics, although it may be found that some larger amplitudes of motion accompany the minimized transmissibility.
Optimal Design of Squeeze Film Supports for Flexible Rotors
Authors: Rabinowitz M. D. , Hahn E. J.
Published: April 2015

Assuming central preloading operation below the second bending critical speed and full film lubrication, this paper presents a theoretical model which allows one, with minimum computation, to design squeeze film damped rotors under conditions of high unbalance loading. Closed form expressions are derived for the maximum vibration amplitudes pertaining to optimally damped conditions. The resulting vibration amplitude and transmissibility data of design interest are presented for a wide range of practical operating conditions on a single chart. It can be seen that for a given rotor, the lighter the bearing the more easily one can satisfy design constraints relating to allowable rotor vibration levels and lubricant supply pressure requirements. The data presented are shown to be applicable to a wide variety of rotors, and a recommended procedure for optimal design is outlined.
Smoke Reduction in FJR-710 Turbofan Engines by an Airblast Combustor
Authors: Eguchi K. , Ishii A. , Kitahara K. , Suzuki K. , Tagashira T.
Published: April 2015

An airblast fuel atomizer was developed to reduce smoke emission levels in FJR-710 engines. Rig tests were made to determine performance and pollutant emissions of the airblast annular combustor over a wide range of inlet pressures and temperatures with nonuniform airflow distributions. No significant problems were observed for flame instability nor for combustor durability. Smoke measurements showed considerably lower levels than conventional pressure-atomized combustors with similar liner configurations. Smoke level at full engine thrust was found to meet the 1984 EPA standard for T2-class engines. Nox-emission levels were below Lipfert correlation data available for existing aircraft engines.
The Control of Engine Vibration Using Squeeze-Film Dampers
Authors: Holmes R.
Published: April 2015

This paper describes the following roles of a squeeze-film damper when used in gas turbine applications as a means of reducing vibration and transmitted force due to unbalance. (a) as an element in parallel with a soft spring in a vibration isolator and (b) as an element in series with the stiffness of the engine pedestal. The effects of cavitation on performance are elucidated and the dangers of jump phenomena and subsynchronous response are discussed. Experimental work is described in which both roles of the squeeze-film damper are investigated and the results are compared with theoretical predictions.
The Elliptic Solution of the Secondary Flow Problem
Authors: Abdallah S. , Hamed A.
Published: April 2015

This paper presents the elliptic solution of the inviscid incompressible secondary flow in curved passages. The three-dimensional flow field is synthesized between 3 sets of orthogonal nonstream surfaces. The two-dimensional flow field on each set of surfaces is considered to be resulting from a source/sink distribution. The distribution and strength of these sources are dependent on the variation in the flow properties normal to the surfaces. The dependent variables in this formulation are the velocity components, the total pressure, and the main flow vorticity component. The governing equations in terms of these dependent variables are solved on each family of surfaces using the stream-like function formulation. A new mechanism is implemented to exchange information between the solutions on the 3 family surfaces, resulting into a unique solution. In addition, the boundary conditions for the resulting systems of equations are carefully chosen to insure the existence and uniqueness of the solution. The numerical results obtained for the rotational inviscid flow in a curved duct are discussed and compared with the available experimental data.
An Approach to Software for High Integrity Applications
Authors: Dolman W. C. , Parkes J. P.
Published: April 2015

This paper outlines one approach taken in designing a software system for the production of high quality software for use in gas turbine control applications. Central to the approach is a special control language with its inherent features of visibility, reliability and testability, leading to a software system which can be applied to applications in which the integrity of the units is of prime importance. The structure of the language is described together with the method of application in the field of aircraft gas turbine control. The provision of documentation automatically is an integral part of the system together with the testing procedures and test documentation. A description of how these features are combined into the total software system is also given.
Eigensolution Reanalysis of Rotor Dynamic Systems by the Generalized Receptance Method
Authors: Palazzolo A. B. , Wang Bo Ping , Pilkey W. D.
Published: April 2015

A method is presented for efficiently calculating the damped natural frequencies of complex rotor bearings systems. The procedure is applicable to the repeated reanalysis of rotor systems during the search for an optimal design. The generalized receptances used in the method are calculated with a series of formulas that improves the convergence characteristics when only an incomplete set of modes is available. A nonsynchronous gyroscopic rotor example is examined to illustrate the reanalysis procedure.
The Identification and Elimination of Non-Independent Balance Planes in Influence Coefficient Balancing
Authors: Darlow M. S.
Published: April 2015

The purpose of this paper is two-fold: first, to discuss the origin and symptoms of the non-independent balance plane problem and thus alert the balancing engineer to its existence; and, second, to provide a systematic method for identifying and eliminating this problem which is consistent with the general influence coefficient balancing procedure.
The Status and Prospects of the Industrial and Marine Gas Turbine With Particular Reference to the RB.211
Authors: Slatter B. H.
Published: April 2015

The development of aero-derived industrial and marine gas turbines over the past twenty years is reviewed in relation to changes in market requirements. The performance of the RB.211 industrial engine is discussed and the forward development prospects are examined. The efficiency is compared with the efficiencies to be expected from more complex cycles and from Diesel engines.
Solution to a Bistable Vibration Problem Using a Plain, Uncentralized Squeeze Film Damper Bearing
Authors: Palladino J. A. , Gray T. W.
Published: April 2015

During service introduction of an uprated turbojet engine, which has a three-bearing rotor support system with an overhung turbine, several problems related to system vibration were encountered — cabin noise and high engine vibration levels. These problems led to a factory and field investigation which showed that the source of the problem was a nonlinear interaction between rotor and casing modes coupled through bearing clearance. This interaction led to a bistable vibration of the system. This paper documents the results of this investigation and demonstrates that the use of a plain, uncentralized, squeeze film damper to support the turbine rotor solves all vibration problems by reducing the turbine critical speed and separating it from the casing mode. Also included are effects of exhaust system weight on engine vibration and cabin noise levels.
Operating Experience With Five Sulzer Gas Turbine-Compressor Modules in an Off-Shore Gas Lift Application
Authors: Brunner A. C. , Maurer A.
Published: April 2015

This paper covers the first two years of industrial operation of five gasturbine-compressor modules operating on a gas-lift platform in the Gulf of Suez. It includes a short description of the installation and of the organization Sulzer has set-up to comply with their maintenance operating contract scheduled for five years of operation. Two major technical problems, one of the gasturbine and the other on the compressor are described in detail as well as the counter measures taken. Results of the first 12,000 hr inspection of a Type S3 gasturbine in off-shore duty as well as the 7% up-rating introduced during the inspection period are mentioned. A detailed operational survey has been carried out during 23 months enabling us to produce confirmed results on utilization, availability and reliability of the turbine-compressor modules.
Field Experience With Pulse-Jet Self-Cleaning Air Filtration on Gas Turbines in a Desert Environment
Authors: Anderson A. W. , Neaman R. G.
Published: April 2015

This paper discusses the results of two years continuous operation of automatic self-cleaning air filtration systems designed to provide gas turbine protection in a desert environment subject to high ambient concentrations of sand, dust and salt. The condition of the gas turbines and associated pulse-jet air filtration systems, after two years continuous operation, are described. Filter operating costs are also analyzed.
Alternative Fuels: Burner Concepts and Emission Characteristics of a Silo Combustor
Authors: Krockow W. , Schabbehard H.
Published: April 2015

As the design philosophy of a silo combustor differs largely from the better known one of smaller can type combustors, the paper describes the impact of alternative fuels on the burner concepts and emission characteristics of the silo combustor. Some published influences of a higher C/H-ratio on wall temperatures and smoke emission could not be observed. The large volume of the silo combustor offers the possibility of burning coal derived gases with heat values as low as 1800 kJ/kg. Nitrogenous liquid fuels need a rich burning first combustion stage with a long residence time. Calculations which closely agree with latest published test results show the pronounced effect of residence time to the rich burn quick quench concept. This becomes even more distinct in the case of a low BTU coal gas containing NH3 or HCN resulting in unrealistic large combustor volumes. In addition, a general graph based on kinetic calculations shows the expected NOx increase or decrease of any kind of CO, H2 and inert concentration in a coal gas related to the NOx result of methane in the same combustor.
Optimum Cycle Parameters of Coal Fired Closed Cycle Gas Turbine in Regenerative and Combined Cycle Configurations
Authors: Rao J. S.
Published: April 2015

This paper presents the methodology developed for the estimation of thermodynamic performance and reports the optimum cycle parameters of coal fired CCGT in regenerative and Combined Cycle Configurations using Air, Helium and Carbon-Dioxide as working gases. A rigorous approach has been followed for the determination of the cycle efficiency by assuming the specific heat of working gases as a continuous function of temperature for accurate estimation of cycle parameters. The performance evaluation of CCGT in combined cycle mode of operation is carried out to optimize the steam bottoming cycle parameters and hence the compressor pressure ratio for achieving the maximum cycle efficiency. From the study it is observed that Helium is the most suitable working gas as it produces high thermal efficiency at a low compressor pressure ratio.
Operating Flexibility and Economic Benefits of a Dual-Fluid Cycle 501-KB Gas Turbine Engine in Cogeneration Applications
Authors: Jones J. L. , Flynn B. R. , Strother J. R.
Published: April 2015

The flexibility of the Dual-Fluid Cycle 501-KB engine in accommodating to time varying process steam demand and peaking power requirements is described. Economic aspects of this engine in cogeneration applications are discussed relative to ownership by a utility, a process steam user or a third party. A specific installation is described for a Dual-Fluid Cycle unit operating in combination with two basic 501-KB cogeneration units. The resultant cost of electrical power for this installation is compared to local commerical rates.
Experimental Investigation of Compressor Cascade Wakes
Authors: Hobbs D. E. , Wagner J. H. , Dannenhoffer J. F. , Dring R. P.
Published: April 2015

This report discusses a cascade wake experiment intended to improve wake modeling in an airfoil analysis. The experiment included extensive measurements of the near and far wakes, trailing edge boundary layers, and airfoil surface static pressures. The measured wake displacement surface and computed boundary layers were used in conjunction with a cascade potential flow solver to demonstrate the feasibility of modeling the viscous aspects of cascade flow.
Conserving Energy by the Efficient Use of the Industrial Gas Turbine
Authors: Lightbody D. M. S.
Published: April 2015

The paper covers the basic thermodynamics of the combined cycle concept and illustrates that energy conservation is possible by coupling the Joule and Rankine cycles. It discusses the optimisation of steam conditions and outlines the concept of the unfired combined cycle. “Carnot efficiency” and “pinch points” are shown to be important as is the concept of “specific work” as it relates to the gas turbine in arriving at the best overall cycle efficiencies. The importance of the efficiency characteristic of the steam turbine is emphasised and it is shown that this characteristic will determine the overall cycle efficiency. It is suggested that steam turbine manufacturers should design and develop steam turbines to match the advanced gas turbines available to-day and so enchance the overall efficiency which can presently be obtained from to-day’s combined cycle. Market forces will tend to bring this about as evidenced by the growing interest being shown in this concept both in the UK and Europe.
Combustor Liner Temperature in the Gas Turbine Using Heavy Fuels
Authors: Najjar Y. S. H.
Published: April 2015

Broadening of aviation fuel specifications has been simulated with blends of gas oil and residual fuel oil. Radiation, smoke and temperature measurements in a developed experimental combustor at various air pressures, inlet temperatures and air-fuel ratios permit derivation of a non-dimensional temperature parameter showing good correlation with theory.
Innovations in Fluid Mechanics Education at the Technical University of Berlin
Authors: Schade H. , Fernholz H.-H.
Published: April 2015

At the Technical University of Berlin, the usual Fluid Mechanics Course for engineering students has been offered since 1977 in two different ways simultaneously, between which the students may choose. One is the traditional scheme of lectures with additional example classes; students can obtain a typewritten summary of the course without the examples. As an alternative the students are provided with a complete text of the course arranged for self-study together with worked examples. This text has now been published as a book (H. Schade, E. Kunz: Strömungslehre. Berlin, New York: de Gruyter 1980). In the alternative course the students meet in groups of about five with a professor or a teaching assistant once a week to discuss the section of the text which they had been given as a reading assignment in the previous week. All students, whether they have attended the traditional or the alternative course, must pass the same written and oral examinations at the end of the one-year course. The advantages and disadvantages of both methods will be discussed and an evaluation will be given.
The Data-Tronic Remote Control-Monitor System
Authors: Johnson D. , Geer D. H.
Published: April 2015

Two Data-Tronic remote control-monitor systems are now in service on multiple gas turbine power plants. In each system eight gas turbine generators are controlled from one station operator’s console, via redundant twisted-pair party line cables. The station operator can also assign control of individual units to a remote dispatching center. In addition to control and display information, the party lines carry comprehensive data from the turbines back to an optional minicomputer for storage. The computer data base can then be analysed to present diagnostic and maintenance information. This paper is a sequel to the author’s 1980 ASME paper on the design of the Data-Tronic system, and describes test performance and field experience.
Centrifugal Compressor Testing Experience and Practice
Authors: Meier R. H. , Rhea C. S.
Published: April 2015

Experience with factory and field performance testing of centrifugal compressors in natural gas service is presented. The ability of different types of factory test arrangements to closely predict future field performance is compared. Instrumentation requirements for achievement of reasonable accuracy in field testing are defined and discussed. Major aspects of mechanical and aerodynamic performance testing are addressed.
Acoustic Control of Dilution-Air Mixing in a Gas Turbine Combustor
Authors: Vermeulen P. J. , Odgers J. , Ramesh V.
Published: April 2015

A small combustor of normal design employing acoustic control of the dilution-air flows has been successfully tested up to “half-load” conditions. It has been shown that this technique can be used to selectively and progressively control the exit plane temperature distribution, and the ability to trim the temperature profile has been convincingly demonstrated. The acoustic driver power requirements were minimal indicating that driver power at “full-load” will not be excessive. The nature of the acoustically modulated dilution-air flows has been clearly establish to the design of combustors such that a desired exit plane temperature distribution may be achieved.
Design Optimization of a Gas Turbine Based Cogeneration Plant With Steam Supply to Process Plant
Authors: Giannuzzi L. F. , Horn O. E. , Nakhamkin N.
Published: April 2015

This paper presents the results of Gibbs & Hill, Inc.’s studies, engineering, and implementation of a cogeneration plant consisting of gas turbines and heat recovery steam generators. The plant is designed for fluctuating power supply and stable steam supply requirements to a multistage flash (MSF) type Desalination Plant. This paper emphasizes the advantages of an Integrated Power/Desalination Plant System Optimization as against separate optimization of power and desalination plants.
A Study of a High Temperature Nuclear Power Plant Incorporating a Non-Integrated Indirect Cycle Gas Turbine
Authors: Sarlos G. , Helbling W. , Zollinger E. , Gregory N. , Luchsinger H.
Published: April 2015

In connection with the HHT-Project, the Swiss Federal Institute for Reactor Research has performed a study of a 1640-MWth HTR-plant incorporating a non-integrated indirect cycle gas turbine with two-stage intercooling, as a possibility of simplifying and reducing the cost of the HHT-Demonstration plant. In this paper, the plant design is described and compared with the HHT-demonstration plant (a CCGT integrated plant with single stage intercooling). Also included is an evaluation of the various advantages and disadvantages of this design together with the presentation of some of the sensitivity results.
The Charging of Diesel Engines for Passenger Cars Using Turbochargers With Adjustable Turbine Guide Vanes
Authors: Rautenberg M. , Mobarak A. , Malobabic M.
Published: April 2015

Turbocharged passenger cars have been in use more than three decades. However, the behavior of the engine at low engine speeds is still unsatisfactory. Experimental work has been carried out on turbochargers aiming to improve the behavior of the engine at low speeds. For this purpose a turbine with adjustable guide vanes has been designed and tested. These experiments were done on a turbocharged 31 diesel engine from Daimler-Benz. Three different turbine nozzle blades have been designed and tested without using a waste gate. The results are compared with those of the Garrett-turbocharger T03 which was originally installed with the engine.
The Low Temperature Properties of Aviation Fuels
Authors: Brunton G. , Willock R. R. , Voisey M. A.
Published: April 2015

A review is presented of work on the low temperature properties of aviation turbine fuels that has been carried out in recent years at Thornton Research Centre. Details of both simulated full scale aircraft tank tests and laboratory evaluations are included. Zero hold up is considered as a low temperature specification parameter and a novel method for measuring its value is described. Experimental results are presented which demonstrate that a change from a freezing point to a flow criterion could provide an increase in fuel availability without prejudicing flight safety.
Reliability Performance of Combustion Turbines in Combined Cycle Duty
Authors: Strong R. E. , Eagle K. H. , Duer M. E.
Published: April 2015

There is a belief held by the electrical utility industry that the combustion turbine is unreliable and has a low availability value. This paper presents field data for combined cycle plants and concludes that the combustion turbine is, indeed, reliable. The importance of improved utility outage planning also is discussed in relation to increased availability values. Finally, areas for further attention are defined and will be the subject of future papers.
Catalytic Burners for Stationary Combustion Turbines: A Preliminary Design Analysis
Authors: Angello L. C. , Pillsbury P. W. , Toof J. L.
Published: April 2015

The EPRI Stationary Gas Turbine Catalytic Combustor Development Program is a multi-year, multi-phase major contract effort. Its objectives are to design, develop and demonstrate a full-scale, field tested stationary gas turbine combustor, employing catalytic combustion technology for reduced NOx emissions. Its focus is the development of a practical and reliable catalytic combustor for current and near-future stationary gas turbine designs fired with low nitrogen (<500 ppm) distillate fuels. The purpose of this paper is to present the results of a preliminary design analysis conducted under the initial tasks of this program.
The Effect of Coolant Flow on the Efficiency of a Transonic HP Turbine Profile Suitable for a Small Engine
Authors: Michel G. W. , Kost F. H.
Published: April 2015

A gas turbine blade with a very thick trailing edge (thickness/throat = 22 percent) has been tested in a plane cascade over the exit Mach number range of 0.7 to 1.3. To investigate the effect of cooling air on the aerodynamic performance, tests have been carried out for the solid blade and by blowing air through slots in the trailing edge of the profile. The results indicate the sensitivity of cascade performance to trailing edge geometry and flow conditions. Especially in the subsonic regime the slotted blades gave an unusual loss reduction which should be attributed to a change in the unsteady separation process at the trailing edge.
Utility Alternatives for Coal-Fired Power Plants
Authors: Lehman S. J. , Robson F. L.
Published: April 2015

In the face of ever escalating costs for fuel oil or natural gas, the utility industry worldwide is investigating the use of coal-based alternatives that offer environmental acceptability and the potential for low-cost electrical power. One attractive alternative is to repower existing oil- or gas-fired power plants with gasified coal-fired gas turbines. Comparisons are made of a 400-MW steam station repowered with Texaco gasification, a grass roots integrated gasification current technology gas turbine, combined-cycle power plant and a conventional coal-fired power plant with flue gas desulfurization. The advantages of repowering are discussed.
A Generalized Numerical Method for Bluff Body and Stalling Aerofoil Flow
Authors: Lewis R. I. , Porthouse D. T. C.
Published: April 2015

A numerical method has been developed for predicting the two-dimensional incompressible separated flow from bluff bodies and aerofoils with preliminary extension to cascades. The paper will present a brief outline of the theoretical method accompanied by illustrations. These include predictions of the vortex streets downstream of circular cylinders and wedge shaped bodies, the stalling behavior of an aerofoil and initial attempts to calculate the vortex motion of a stalling cascade. The method makes use of the surface vorticity technique extended to include vorticity shedding and convection with the mainstream.
Test Facility and Data Handling System for the Development of Axial Compressors
Authors: Reusch A. C. , Timberley S.
Published: April 2015

The test installation and the data acquisition system used in the aerothermodynamic development of the axial compressor for a new Ruston 6-MW industrial gas turbine are described. Developments in instrumentation techniques are discussed. Processing of the data is outlined and data are presented for a typical graphical output. The merits of the flexibility achieved, both for the aerothermodynamic test facility and the data acquisition system, are discussed. The potential of the installation for the development of other axial compressors is outlined.
The ADC Method: A Rapid Numerical Technique for Solving Three-Dimensional Navier-Stokes Equation
Authors: Ge Gao
Published: April 2015

The artificial damping and compressibility method (ADC) is a rapid numerical technique for solving steady three-dimensional incompressible and compressible Navier-Stokes equation. The principle of this method lies in the introduction of an artificial damping factor into the group of linear equations, by which the elliptic equation is replaced, and the final results do not depend on the artificial terms. The consistency of this method for viscous flow is proved theoretically. The advantages of the SMAC method, the artificial compressibility method and the dynamic relaxation method are retained in the ADC method. Sample calculation of a bending jet is included. The results show that the convergence rate for calculating three-dimensional elliptic flow problems increases by 3–4 order of magnitude as compared with the SOR method.
Coherent Structure of the Turbulent Boundary Layer at Low and High Velocities
Authors: Zakkay V. , Barra V.
Published: April 2015

An attempt to obtain a description of the coherent, or quasi-ordered structure of the turbulent boundary layer in the lateral direction at low and high velocity is presented in this paper. Simultaneous measurements of velocity, wall pressure and wall shear fluctuations at U∞ = 10, 22.4 and 206 m/sec have been analyzed to obtain a description of the so-called “turbulent burst.” A conditional sampling scheme has been applied to the digitized fluctuations to identify the occurrence of bursts, and their spread thereof in the lateral direction. The results for the lateral spread of the “bursts” indicate that the events can be separated into two groups with opposite phase relationship across the lateral measurements and is thought to be an indication of “arrow-head” or “horseshoe” type shape. The angular spread of the “horseshoe” may be estimated and therefore the angle of each “leg” which makes the x axis may be determined. These results lead to the conclusions that the flow structures at high velocities tend to be very narrow and swept back at, or near the wall and are much wider and flatter away from the wall.
A Lube System Diagnostic Monitor With Deaeration Capability
Authors: Tauber T. , D’Ambrosia S. , Rudbarg F.
Published: April 2015

A high-performance, full-flow oil debris monitor with deaeration capability has been developed for the GTEC TPE331-14 and -15R turboprop engines. In an effort to systematically investigate the performance of the unit over a range of operating conditions, it was subsequently tested at flow rates from 5 to 15 gpm oil, aeration ratios of 1:1 to 1:4 and temperatures from ambient to 300° F. The effects of varying the inlet and air outlet nozzle diameters were also investigated. The air separation efficiency of the unit exceeds 99 percent. Oil separation is better than 90 percent over the range of flows and exceeds 98 percent at 10 gpm oil flow and aeration ratios of 3 and 4. At the same time, the debris capture efficiency of the unit is practically 100 percent for particle sizes of 250 microns and above at engine operating temperatures. The pressure drop for the unit is approximately 13 psi. It is demonstrated that an increase in the inlet nozzle diameter reduces the pressure drop to 10 psi or below with only negligible loss in debris capture efficiency.
Mechanical Drive Steam Turbine Efficiency Improvement
Authors: Provenzale G. E.
Published: April 2015

Special purpose steam turbine driver efficiency improvements offer significant energy saving incentives, particularly in today’s environment of soaring energy costs. Efficiency gains of up to ten percentage points are possible over past designs with up-to-date technology and can provide substantial operating cost savings for current energy costs. This paper reviews (1) governing factors for turbine efficiency improvement, (2) currently implemented design modifications, and (3) recommended approach to developing the “next generation” steam turbine technology.
Heavy Fuels Ash Deposit Formation and Removal in Water-Cooled High Temperature Gas Turbines
Authors: Blanton J. C. , Durgin G. A. , Palko J. E.
Published: April 2015

Experimental data obtained in heavy fuels operation of a gas turbine simulator with a water-cooled, transonic turbine nozzle cascade are presented. The ash fouling is characterized by the rate of decrease of the aerodynamic throat area. Particular attention is given to the cleanability of the ash deposits. A simple heat transfer analysis was performed to assist in evaluating the data. The rate of ash fouling in the water-cooled nozzle was found to be of the same order of magnitude as for conventional air-cooled designs. Cleanability, both on and off-line, was found to be significantly enhanced, thus making the water-cooled gas turbine an attractive alternative for heavy fuels applications.
Two-Phase Transpiration Cooling
Authors: El-Masri M. A.
Published: April 2015

Two-phase transpiration is shown to possess considerable potential for gas turbine cooling. In this concept, water fed into a porous component boils within the wall. The resulting steam issues from the hot surface forming the transpiration film. A model for the performance of such a system is developed. Assuming constant properties and a linear reduction of Stanton number with transpiration rate, closed-form solutions are obtained. The governing dimensionless parameters are identified, the system behavior predicted, and the modes of operation delineated. Those are defined as two-phase, partially-flooded, and completely-flooded modes. At low values of a certain “modified Peclet number,” the two-phase mode is unstable and the system tends to flood. Large values of this parameter indicate stable, well-regulated behavior. Discussions on gas turbine applications are presented. A typical numerical example is given in the Appendix.
A Theory for Boundary Layer Growth on the Blades of a Radial Impeller Including End Wall Influence
Authors: Ekerol H. , Railly J. W.
Published: April 2015

Experimental data on the wall shear stress of a turbulent boundary layer on the suction side of a blade in a two-dimensional radial impeller is compared with the predictions of a theory which takes account of rotation and curvature effects as well as the three-dimensional influence of the end-wall boundary layers. The latter influence is assumed to arise mainly from mainstream distortion due to secondary flows created by the end-wall boundary layers and it appears as an extra term in the momentum integral equation of the blade boundary layer which has allowance, also for the Coriolis effect; an appropriate form of the Head entrainment equation is derived to obtain a solution and a comparison made. A comparison of the above theory with the Patankar-Spalding prediction method, modified to include the effects of Coriolis (including mixing length modification, MLM) is also made.
The Effect of Inlet Distortion on the Performance Characteristics of a Centrifugal Compressor
Authors: Ariga I. , Kasai N. , Masuda S. , Watanabe Y. , Watanabe I.
Published: April 2015

The present paper concerns itself with the effects of total pressure (and thus velocity) distortion on performance characteristics and surge margin of centrifugal compressors. Both radial and circumferential distortions were investigated. The performance tests as well as the velocity measurements within the impeller passages were carried out with a low speed compressor test rig with the inlet honeycomb as the distortion generators and compared with the case of “no distortion” as a datum. The results indicated that the inlet distortion exerted unfavorable influences on the efficiency and the surge margin of the given compressor, though the influence of the radial distortion was much stronger than that of the circumferential one. Various distortion indices were further examined in order to correlate the performance to the inlet distortion.
NOx Abatement via Water Injection in Aircraft-Derivative Turbine Engines
Authors: Bahr D. W. , Lyon T. F.
Published: April 2015

The results of analytical and experimental investigations to develop efficient and reliable water injection methods for reducing the nitrogen oxides (NOx) levels of the LM2500 and LM5000 engines are presented. These aircraft-derivative turbine engines are equipped with compact annular combustors. In these investigations, various methods of injecting water into the combustor primary zone were evaluated in combustor and engine tests to identify methods with minimal water flow requirements for a given degree of NOx abatement. Primary emphasis was focused on the development of methods of injecting liquid water into the engines when operating with distillate fuels. Methods of injecting both liquid water and steam when operating with natural gas were also investigated. The impacts of water injection on combustor and engine performance and operability were additionally assessed. Satisfactory accommodation of water/fuel weight ratios above unity and associated NOx level reductions as high as 90 percent were demonstrated.
A Design Approach for a Practical Turbojet Engine Combustor Diffuser System
Authors: DuBell T. L. , Russell P. L. , Reilly R. S.
Published: April 2015

The combustion system in a gas turbine engine is the source of the energy released to produce propulsive power. Maintaining stable combustion and achieving good performance requires controlled introduction of air and good mixing in the combustor. The compressor discharge velocity must be reduced by diffusing the air before it reaches the combustor. There are fundamental and practical limits on how much diffusion can be done, and parasitic loss of pressure is introduced. This paper describes an approach to achieving an improved, cost effective diffuser design. The diffuser that results provides excellent performance, is simple, and is dynamically stable.
Numerical Simulation of Single, Double, and Multiple Row Film Cooling Effectiveness and Heat Transfer
Authors: Miller Kevin L. , Crawford Michael E.
Published: April 2015

A numerical procedure previously developed to simulate heat transfer with full-coverage film cooling has been successfully applied to film cooling geometries that incorporate single, double, and multiple rows of cooling holes. The procedure is based on the STAN5 boundary layer program with models added to simulate film coolant injection and turbulence augmentation. Experimental data for comparison have been extracted mostly from the open literature, and the data represent a wide variety of film cooling geometries. Both spanwise-averaged film cooling effectiveness and heat transfer data are considered. Linear superposition theory for film cooling is tested by comparing superposition predicted effectiveness with the experimental values.
The Active Magnetic Bearing Enables Optimum Damping of Flexible Rotor
Authors: Habermann Helmut , Brunet Maurice
Published: April 2015

The active magnetic bearing is based on the use of forces created by a magnetic field to levitate the rotor without mechanical contact between the stationary and moving parts. A ferromagnetic ring fixed on the rotor “floats” in the magnetic fields generated by the electromagnets, which are mounted as two sets of opposing pairs. The current is transmitted to the electromagnetic coils through amplifiers.

The four electromagnets control the rotor’s position in response to the signals transmitted from the sensors. The rotor is maintained in equilibrium under the control of the electromagnetic forces. Its position is determined by means of sensors which continuously monitor any displacements through an electronic control system.

As in every control system, damping of the loop is provided by means of a phase advance command from one or more differenciating circuits of the position error signal.

The capability of modifying the electromagnetic force both in terms of amplitude and phase leads to the benefit of specific properties for the application, in particular:

- automatic balancing characterized by the rotation of the moving part around its main axis of inertia, and not around the axis of the bearings allowing operation without vibrations,

- adjustable damping of the suspension allowing easy passing of the critical speeds of the rotor,

- high and adjustable stiffness yielding maximum accuracy of rotor equilibrium position,

- permanent diagnosis of machine operation due to the knowledge of all rotation characteristics (speed, loads on the bearings, position of the rotation axis, eccentricity, out-of-balance, disturbance frequency).
Measurements of Low Level NOx Emission From a Cheng Cycle Gas Turbine
Authors: Chang Chung-Nan , Digumarthi Ramarao
Published: April 2015

Mass steam injection into the combustor of a Cheng Cycle turbine can influence combustion characteristics and pollutant formation.

When using a Cheng Cycle system based on a Garrett 831 gas turbine liquid fuel, these influences were studied experimentally. Data obtained to date indicate that significant NOx reduction can be achieved without suffering combustion inefficiency or instability.
Cogeneration and Multiple Heat Recovery at a Plastics Manufacturing Facility
Authors: Davidse J. , van Ooststroom A. P.
Published: April 2015

This paper describes the process of the integration of a cogeneration plant in a plastics manufacturing complex, which is being expanded.

It presents the background against which the decision to proceed was made, the alternatives considered, and some of the techniques utilized to obtain management approval.

It also describes the specific aspects of the cogeneration facility, fuels, heat recovery systems for thermal oil and medium pressure steam, the balancing between energy production and utilization in the complex and the control system for the optimization of the facility.

Also some energy typical aspects of connecting the generator to the public grid will be addressed.
Processing of Sintered Alpha SiC
Authors: Storm Roger S.
Published: April 2015

The Carborundum Company has been involved in the manufacture of alpha SiC for close to 100 years. The historical usage of this material has been as a coarse grain for the abrasive industry. Several Carborundum manufacturing plants are in existence worldwide and each has a capacity of approximately 40,000 tons/year of SiC powder produced by the Acheson process in which a graphite electrode is encased in a mixture of sand (SiO2) and coke. After the mass is heated to 4000°C and allowed to cool, the crystalline SiC grain is obtained directly (Figure 1). A milling and classification procedure is then employed to produce the desired grain sizes.

In 1975, researchers at Carborundum discovered a process for making high density, high strength monolithic shapes of alpha SiC(1). This involved using a submicron sized powder blended with sintering aids (boron and carbon). The mixture is green compacted and heated to above 2000°C under inert gas at atmospheric pressure. A solid state grain boundary diffusion process results in a densification process with an accompanying linear shrinkage of approximately 18%, to produce a body with 95–99% of theoretical density (3.21 gm/cc), and properties which are of interest for engineering applications. The pressureless sintering allows the formation of complex geometries by a net shape process without grinding, thus, creating the potential for the economical production of precision components in high volume.
The Design Manufacture and Operation of a Model Turbine Test Rig
Authors: Gosling M. C.
Published: April 2015

This paper describes the design, construction and development of a rig that allows small scale model turbines to be tested at near ambient conditions and low power levels. The objective being to obtain reliable performance data quickly and at low cost. The testing of a model turbine, installed in this rig, is described and design details of the turbine are included.
Design and Development of a Process Plant Gas Generator Installation
Authors: Reynolds G. A.
Published: April 2015

In 1972 El Paso Products investigated the possibility of replacing their existing industrial gas generators with an alternative. These gas turbines provided a constant hot gas flow to the catalysts of their butadiene plant in Odessa Texas. This project demanded the highest reliability and offered some unique engineering challenges.
Co-Generation Plant in the Powerworks of the Hague (The Netherlands)
Authors: de Clercq A. S.
Published: April 2015

In the beginning of 1983 a combined cycle unit consisting of 2 Rolls-Royce gasturbines, 2 flue gas boilers and a DeLaval-Stork steam turbine was set in service. This unit has an output of 76.5 MW electrical and 80 MW thermal power. Experiences obtained during the first period of service are delt with.
Ceramic Engine Components Under Commercial Production
Authors: Hamano Yoshiteru , Yamamoto Masahiro
Published: April 2015

In the field of diesel engine components, ceramic glow plugs assisting quick start up of chamber diesel engines had been developed in September, 1981 and ceramic swirl chambers followed in commercialization in April, 1983. These ceramic components are currently under commercial production and are installed on passenger cars on the merket.

Silicon nitride (Si3N4) is the material of these components, and a lot of mass-production technique has firmly established in order to achieve competitive price and high durability in comparison with the conventional metal components.

Because of its excellent heating characteristics, ceramic glow plugs have eliminated the “waiting time” before the start-up of diesel engines. As the result, drivers can enjoy quick starting of engines as they can do with gasoline fueled vehicles. Ceramic swirl chambers could drastically reduce idling noise of diesel engines and remarkably improved starting performance in the cold climate operation.
A Simple Method for Solving Three-Dimensional Inverse Problems of Turbomachine Flow and the Annular Constraint Condition
Authors: Xiao-lu Zhao , Chun-lin Sun , Chung-Hua Wu
Published: April 2015

In ASME paper 50-A-79, it was suggested that the three-dimensional inverse (design) problem of turbomachine flow may be solved approximately by a Taylor series expansion in the circumferential direction based on the known flow variation over an S2 stream surface in the mid-channel of the blade passage. This idea has been realized recently.

A new coordinate transformation has been developed. The coordinate surfaces are coincident with the S2 stream surfaces. This transformation leads to a new method to calculate the aerodynamic equations of 3-D flow. By the use of this transformation, a high order expansion is realized to determine the shape of the blade surfaces from the fluid state on the S2m stream surface directly.

Computation in this manner soon leads to the discovery that theoretically the distribution of flow parameter (usually vθr) on S2m prescribed by the designer should satisfy a constraint condition, which guarantees that the S1 stream surfaces along the hub and shroud obtained from circumferential extension of the S2m surface are surfaces of revolution. An approximate method is suggested to meet this condition.
Gas Turbine Blade Materials’ Corrosion in the Effluent From a Pressurized Fluidized Bed Combustor
Authors: McCarron R. L. , Brobst R. P.
Published: April 2015

Two nominally 200-hour tests were conducted in the General Electric Company’s Pressurized Fluidized Bed (PFB) Coal Combustion facility in Malta, NY. The purpose of the tests was to evaluate the influence of bed operating temperature and dolomite composition on the degradation of gas turbine vane and blade base alloys and protective coating/cladding systems in the effluent from a PFB. Operating conditions were as follows: 1) 1710°-1770°F (932°C-966°C) bed temperature and Pfizer dolomite (0.1 wt% sodium plus potassium), and 2) 1630°-1690°F (888°-921°C) bed temperature and Tymochtee dolomite (0.9 wt% sodium plus potassium). Brookville seam coal with 4.5 wt% sulfur, 0.3 wt% alkali, and 0.17 wt% chlorine was used in both tests.

Bare nickel and cobalt-base vane and blade alloys were susceptible to hot corrosion over the entire temperature range investigated, 1100°-1600°F (593°-871°C). CoCrAlY and FeCrAlY overlay coatings showed good corrosion resistance at temperatures above 1450°F, but were susceptible to pitting attack at lower temperatures. A platinum-aluminide diffusion coating showed excellent corrosion resistance at all temperatures.
Common Misconceptions in the Calculation of Transonic Full Potential Flows
Authors: Dulikravich George S.
Published: April 2015

Reasons for certain inaccuracies in the majority of existing computer programs that numerically calculate transonic full potential flows are clearly exposed. Problems of post-shock oscillations, non-unique shock strengths and their locations, diverging solutions of choked nozzle flows and flows about sharp leading edges are shown to be related to widely accepted oversimplifications in the treatment of boundary conditions. Forms of numerical dissipation that are presently widely used are shown to be not fully understood and an alternative dissipation generation concept is proposed.