bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-Contact System Provides Measurement and Management of Shaft Horsepower
Authors: Parkinson J. R.
Published: April 2015

For years, manufacturers and users of rotating machinery have searched for an accurate and easily used shaft power measurement technique. These users wanted a system with characteristics such as non-contact, no field calibration, shaft realignment compensated, adaptable to control and protective functions, plus high component reliability and accuracy. This paper describes such a system.
Gas Turbine Recuperator Technology Advancements
Authors: McDonald C. F.
Published: April 2015

Because of intense development in the aircraft gas turbine field over the last 30 years, the fixed boundary recuperator has received much less development attention than the turbomachinery, and is still proving to be the nemesis of the small gas turbine design engineer. For operation on cheap fuel, such as natural gas, the simple cycle-engine is the obvious choice, but where more expensive liquid fuels are to be burned, the economics of gas turbine operation can be substantially improved by incorporating an efficient, reliable recuperator. For many industrial, vehicular, marine, and utility applications it can be shown that the gas turbine is a more attractive prime mover than either the diesel engine or steam turbine. For some military applications the fuel logistics situation shows the recuperative gas turbine to be the most effective power plant. For small nuclear Brayton cycle space power systems the recuperator is an essential component for high overall plant efficiency, and hence reduced thermal rejection to the environment. Data are presented to show that utilization of compact efficient heat transfer surfaces developed primarily for aerospace heat exchangers, can result in a substantial reduction in weight and volume, for industrial, vehicular, marine, and nuclear gas turbine recuperators. With the increase in overall efficiency of the recuperative cycle (depending on the level of thermal effectiveness, and the size and type of plant), the cost of the heat exchanger can often be paid for in fuel savings, after only a few hundred hours of operation. Heat exchanger surface geometries and fabrication techniques, together with specific recuperator sizes for different applications, are presented. Design, performance, structural, manufacturing, and economic aspects of compact heat exchanger technology, as applied to the gas turbine, are discussed in detail, together with projected future trends in this field.
Work in Progress in France Related to Computation of Profiles for Turbomachine Blades by Hodograph Method
Authors: Legendre R. G.
Published: April 2015

The hodograph method has been used extensively in France for the computation of turbomachine blade profiles. The work started in 1939 but the industrial development took place during the last decades. This paper presents recent research and the results obtained. The method used in “Association Technique pour la Turbine à Gaz” (ATTAG) and in industry concerns the assimilation of the real fluid to the Chapligin ideal fluid. It permits only calculation of profiles for subsonic flows but provides quite satisfactory predictions for velocities near the critical value. It is easy to use. More complicated developments are undertaken for defining profiles adapted to reversible transonic flows, i.e., without shock. Different methods providing similar results are being studied by several groups in ONERA.
Recent Radial Turbine Research at the NASA Lewis Research Center
Authors: Rohlik H. E. , Kofskey M. G.
Published: April 2015

The high efficiencies of small radial turbines have led to their application in space power systems and numerous APU and shaft power engines. Experimental and analytical work associated with these systems has included examination of blade shroud clearance, blade loading, and exit diffuser design. Results indicate high efficiency over a wide range of specific speed and also insensitivity to clearance and blade loading in the radial part of the rotor. The exit diffuser investigation indicated that a conventional conical outer wall may not provide the velocity variation consistent with minimum overall diffuser loss. A list of recently published NASA radial turbine reports is included.
Compressor Separately Driven Gas Turbine for Marine Use
Authors: Tamaru S. , Fujimoto H.
Published: April 2015

This paper discusses the design study of a new gas turbine cycle for marine use. General characteristics of the cycle are investigated by simple calculations and a design study of a 40,000-hp power plant is presented. Evaluating this power system, an 80,000-hp high-speed container ship is taken as an example and is compared with diesel engine propulsion.
Supersonic Exit Flow of Two-Dimensional Cascades
Authors: Lichtfuss H. J. , Starken H.
Published: April 2015

In this paper the supersonic exit flow field of a two-dimensional cascade is described. Different flow configurations at axial subsonic and supersonic velocities are discussed in detail and calculation methods are presented. The range of possible cascade operation and its dependency of back pressure is evaluated. It is shown that the exit flow field of a double infinite cascade can be simulated behind a semi-infinite cascade.
A Comparison of Calculated Flows in Radial Turbines With Experiment
Authors: Cartwright W. G.
Published: April 2015

The flow in the rotors of three radial turbines, of differing peak efficiency, is analyzed using a streamline curvature method. The turbine of greatest efficiency is analyzed at both on- and off-design conditions; the other two turbines at the design point only. Comparison is made between the predictions of the calculation and the experimental determination of two features of the flow — the shroud static pressure distribution and the outlet velocity profile. Fair agreement with the shroud pressure is obtained at on-design conditions, but correlation with the exit velocity distribution is poor. Some improvement in the calculation of the exit profile is achieved when the analysis is modifed so as to allow for the experimentally observed angle of deviation at the blade trailing edge. Consideration is given to the ability of the analytical method to discriminate between turbines which prove experimentally to have high or low peak efficiency.
Metal-Reinforced Ceramic Composites for Turbine Vanes
Authors: Bortz S. A.
Published: April 2015

Experiments have been performed which indicate the potential of metal-fiber reinforced-ceramic matrix composites for use as a high temperature structural matrix. The results of this work reveal that metal-fiber reinforced ceramics obey compostie theory, and that after cracks occur in the matrix, a pseudo-ductility can be introduced into the composite. This toughness can be predicted from equations of work required to pull the fibers through the matrix. The relationship between strength, toughness, and crack depths, are dependent on the inter-facial bond between the fibers and matrix as well as fiber diameter and length. Based on the results of these experiments, multicomponent materials with superior resistance to failure from oxidation, thermal shock, and high mechanical stresses in air above 2400 F can be postulated. These materials have potential for use as gas turbine engine vanes.
Experimental Investigation of Gas-Particle Flow Trajectories and Velocities in an Axial Flow Turbine Stage
Authors: Tabakoff W. , Hamed A. , Hussein M. F.
Published: April 2015

This paper describes the results from an investigation of the gas-particle flow trajectories, velocities and pressure distribution in an axial flow turbine stage. A gas-particle flow cascade tunnel and high-speed photographic techniques were used to conduct the experimental investigation. The pressure distribution on the blade surface was measured and compared with the theoretical analysis, the results exhibiting good agreement between the developed theory and experiment.
Correlation of Gas Turbine Emissions Data
Authors: Lipfert F. W.
Published: April 2015

Analysis of existing gaseous emissions data from gas turbines has shown that a substantial improvement in data correlation is possible. These correlations serve to increase confidence in the data, identify out-of-control points, and facilitate comparisons between engine models. Furthermore, the NOx correlation implies that a simplified primary zone mathematical model may be used to formulate trends or influence coefficients, which may be used to adjust experimental data to a common base for comparison to a specification. Finally, the presence of water vapor in the combustion air is seen to have a noticeable effect on NOx emissions. This effect should be accounted for in comparing experimental results.
Supersonic Turbine Design and Performance
Authors: Goldman L. J.
Published: April 2015

Methods for designing supersonic stator and rotor blading corrected for boundary layer displacement thickness are summarized. Computer programs based on these methods have been reported in NASA publications. Analytical blade losses for blading of this type are presented and design limitations resulting from consideration of flow separation and supersonic starting are discussed. In addition, a summary of the experimental performance of a single-stage turbine designed by these methods is given.
Design Studies of Lift Fan Engines Suitable for Use in Civilian VTOL Aircraft
Authors: Roelke R. J. , Zigan Steve
Published: April 2015

Low pressure ratio fan engines are receiving increasing attention as a means to provide low speed lift for civilian VTOL transports. Two general types of fan lift engines that are being studied are integral fans and remote powered fans. Preliminary engine design studies of both types of lift fan systems have been made. This paper summarizes a portion of the results of the engine design studies, including the crucial engine requirements, and some of the characteristics of the emerging engine designs of each type.
Futher Development of a 3000-HP Industrial Gas Turbine for Generator Drive Application
Authors: Croker D. M. , Pichel P. W.
Published: April 2015

This paper is a follow-up to ASME Paper 70-GT-9, “Development of a 3000-HP Industrial Gas Turbine Engine,” and covers further development accomplished during the past two years to adapt the engine to generator drive applications. Specific areas which are covered in detail include: (a) mechanical features of the single-shaft rotor and output drive system as distinct from the two-shaft design; (b) combustor and fuel injections system development for liquid (diesel) fuel and dual fuel capability; (c) fuel control system development; and (d) hydroelectric starting system.
Using Solid-State Joining in Gas Turbine Engines
Authors: Martin D. C. , Miller F. R.
Published: April 2015

The ability to fabricate materials and components needed to improve gas-turbine engine performance depends on an ability to achieve reliable joints. Solid-state joining provides this ability. Diffusion bonding of compressor blades, friction welding of engine rotors, and solid-state bonding of turbine shafts by coextrusion of dissimilar metals are discussed as examples of applications of solid-state bonding. Parts made by these techniques have successfully completed engine tests.
A Three Thousand-Hour Durability Test of a Marine Gas Turbine Engine
Authors: Maas L. M. , Miller C. L.
Published: April 2015

The Allison Model 501 industrial gas turbine engine has been used extensively as a prime mover for industrial applications. The areas of application to date have been in the driving of electrical generators and natural gas compressors. This paper describes a 3000-hr durability test of a modified Allison Model 501-K15 engine with saltwater ingestion, 100 F engine inlet air temperature, and operating on Navy distillate fuel. The purpose of the test was to verify that the engine was qualified for marine environmental applications. Performance data, photographs of the installation and engine components, and inspection results are included in this paper.
Propulsion Control Considerations for V/STOL Aircraft
Authors: Lenox T. G.
Published: April 2015

Potential control requirements of various propulsion systems are currently being studied for V/STOL aircraft applications. This paper identifies the considerations which will affect the design of propulsion control systems for both military and commercial aircraft. Of the requirements common to all configurations, the need for improved thrust control is emphasized as requiring total aircraft system trades to establish an approach which provides the desired power management performance with minimum weight and with maximum reliability and maintainability.
Advances in High Power Packaging With Gas Turbines
Authors: Bernstein Ernest
Published: April 2015

This paper describes the TP&MS 45 MW Twin Pac, which consists of two counter-rotating gas turbines driving one generator, and describes its development from the time of the first installed unit through March, 1972. The various applications and operating features of the unit are presented with a description of the major equipment which makes up the unit. It also discusses the installation features, including a new testing concept, and some of the problems that have been overcome in the design of the Twin Pac.
Hot Corrosion of Gas Turbine Rotor Blade Materials due to a Long Term Field Testing
Authors: Doi H. , Onoda T. , Harada Y.
Published: April 2015

As a result of 22,000 hr gas turbine engine operation burning residual oil fuels of high sulfur concentration, Inconel-700 blade has been severely affected owing to hot corrosion, whereas Inconel-X has been virtually free from such an attack. Consideration of the alloy composition suggests that molybdenum and cobalt in Inconel-700 and iron in Inconel-X are important elements in relation to hot corrosion. On the basis of metallographic, electron microprobe and X-ray diffraction analyses, the effect of the alloy composition in regard to hot corrosion mechanisms has been discussed in some detail.
Continuous Measurement of Exhaust Emissions From a High Pressure Cannular Combustor
Authors: Shaw H. , Taylor W. F. , McCoy C. J. , Skopp A.
Published: April 2015

A high pressure cannular combustor has been developed to simulate aircraft turbine engine emissions. In conjunction with this combustor, a continuous analytical and sampling system was assembled. This system is capable of complete on-the-spot analysis of CO2, O2, CO, H2O, unburned hydrocarbons, and NOx. The measured emission levels obtained from burning Jet A are in good agreement with those reported from operating aircraft turbine engines. Data showing the effect of equivalence ratio and pressure on the concentration of combustion products are presented.
The NASA Quiet Engine Program
Authors: Kramer J. J. , Montegani F. J.
Published: April 2015

The NASA Quiet Engine Program will incorporate all available noise-reduction technology into a propulsion system suitable for subsonic civil transport aircraft. Full-scale experimental hardware is being built and tested primarily for noise performance. The program is in process, and component and engine tests to date indicate that it is possible to achieve or exceed noise reduction objectives of 15–20 PNdB below the levels of 707/DC-8 long-range transport aircraft.
Improvement in Recuperative Gas Cycles by Means of a Heat Generator Partly By-Passing the Recuperator: Application to Open and Closed Cycles and to Various Kinds of Energy
Authors: Tilliette Z. P. , Pierre B.
Published: April 2015

A particular arrangement applicable to open or closed recuperative gas cycles, consisting of a heat generator partly by-passing the low pressure side of the recuperator, is proven to enhance the advantages of gas cycles for energy production. In this way, the cogeneration of both power with high efficiency owing to the recuperator and high temperature process heat becomes possible and economically attractive. Furthermore, additional possibilities appear for power generation by combined gas and steam or ammonia cycles. In any case, the overall utilitization coefficient of the primary energy is increased and the combined production of low or medium temperature heat can also be improved. The great operation flexibility of the system for combined energy generation is worth being emphasized: the by-pass arrangement involves no significant change in the operating conditions of the main turbocompressor as the heat output varies. Applications of this arrangement are made to open and closed gas cycle power plants using fossil, nuclear and solar energies. The overall heat conversion efficiency is tentatively estimated in order to appreciate the energy conversion capability of the investigated power plants.
Installation Priorities Yachts vs Ferries vs Gunboats
Authors: Lauriat T. B.
Published: April 2015

Gas turbines under 5000 hp in size used for nain propulsion in smaller vessels (under 200 ft), eventually find themselves installed in a variety of craft: pleasure craft, commercial craft, and military craft. Although the engines, and sometimes the propulsion, are the same, they will enjoy (or suffer) considerable differences in installation features due to the use or owner of the vessel. The similarity of a 100-ft yacht, ferry or gunboat as regards the installation priorities of the turbine propulsion system generally ends at the length of the ship. This paper will use several recently delivered vessels, under construction programs and newly designed craft as examples to provide installation background data which might guide in future considerations of turbines for these different vessel types.
Analytical Consideration of Fuel Economy and Dynamic Response of a Regenerative High Temperature Automobile Gas Turbine: Part I
Authors: Itoh T. , Yamazaki S. , Takeuchi T. , Kosuge H. , Ishida T.
Published: April 2015

Ceramic gas turbines are being studied in many countries for future use as automobile engines. Ceramic turbines were also examined here to determine their potential as engines for passenger cars. Initially, it was found that in the Japanese 10-mode driving cycle and at a turbine inlet temperature (TIT) of 1350 C, the turbine fuel economy was not better than current gasoline engines. On the other hand, it was also found that fuel economy is greatly improved if the air flow at idle conditions is reduced to 1/2 by using, for example, variable geometry components. It is pointed out that a simulation technique is available for estimating the dynamic characteristics of regenerative gas turbine engines, including consideration of variable geometry components. However, satisfactory regenerator models were not readily available. Hence, an experimental regenerator model was made. Where compared with test values, comparatively good results were obtained. Part II of this paper will report in the future on how these models were applied to an engine and what results were obtained from the dynamic simulation of the regenerative, high temperature gas turbine.
The Effect of Hub Inlet Boundary Layer Skewing on the Endwall Shear Flow in an Annular Turbine Cascade
Authors: Bindon J. P.
Published: April 2015

The inner annulus endwall boundary layer between the blades was examined experimentally in an annular turbine cascade for conditions of inlet boundary layer skewing similar to that in a real machine and for the collateral inlet as in all cascade tests. Skewing was introduced by rotating the hub ahead of the cascade. The slot created ahead of the cascade by the rotating hub caused major changes in the endwall surface flow visualization patterns seen as compared to an uninterrupted inlet section. Skewing did not alter the basic pattern except to increase the surface crossflow angles. Traverses taken at 15 points between the blades showed a sharp thickening followed by sharp thinning of the boundary layer near the pressure surface leading edge. The overall distribution of displacement thickness was not greatly influenced by skewing and generally showed a thicker layer near the suction surface and an extremely thin layer near the pressure surface at exit. Skewing increased significantly the amount of fluid involved in crossflow. While surface crossflow angles were everywhere greater with increasing inlet skewing, the increases were more marked in the mid to upper reaches of the shear layer. Loss profiles near the inlet showed the presence of high energy fluid near the surface but near the exit skewed and collateral profiles were more similar.
A Review of Small Gas Turbine Combustion System Development
Authors: Saintsbury J. A. , Sampath P.
Published: April 2015

The EPA aircraft emission regulations were promulgated in 1973 and resulted in urgent investigations of many approaches aimed at reducing gas turbine emissions with minimum penalties to normal combustion performance. The impact of this work on small aircraft gas turbine engines is discussed, and emission reduction techniques and data are presented. Unique problems experienced with smaller gas turbine combustion systems are reviewed as are the potential difficulties of developing higher performance small combustors in the future, without the benefit of the complex and costly mechanical approaches which are applicable to the larger engines. The impact of relaxed fuel specifications and alternate-source gas turbine fuels is discussed in terms of altered fuel properties and development of fuel injection technology.
Alternate Fuels and the Gas Turbine Catalytic Combustor
Authors: Pfefferle W. C.
Published: April 2015

Inasmuch as conventional gas turbine combustors often produce soot even with the present low aromatic content fuels, the production of acceptable liquid turbine fuels from hydrogen deficient raw materials such as coal and tar sands requires large quantities of high cost hydrogen if conventional combustors are to be used. The economics of producing alternate turbine fuels would be improved if high aromatic content fuels could be burned in gas turbines without soot formation. Gas turbines using the catalytic combustor not only can efficiently burn highly aromatic fuels without soot formation but can meet all existing or proposed regulations on emissions of hydrocarbons, carbon monoxide, and nitrogen oxides. Under certain conditions, high fuels can be burned with as little as 10 to 15 percent conversion of the fuel nitrogen to nitrogen oxides. In view of the potential savings, any program for alternate fuels should take into account the opportunities offered by the catalytic combustor.
Experimentally Determined Catalytic Reactor Behavior and Analysis for Gas Turbine Combustors
Authors: Lew H. G. , Dickson W. H. , Decorso S. M. , Olson B. A. , Heck R. M.
Published: April 2015

Investigations contributing to the development and design of the low emission catalytic reactor to be used in large industrial combustion turbine applications are considered. Experimental results on the behavior of catalytically supported combustion under typical operating conditions are presented. They were obtained by burning No. 2 oil in a flow passage containing an Engelhard catalyst. Temperature measurements are made by specially designed thermocouples along the axial direction of the monolithic substrate. These measurements, at steady-state conditions, include axial variation through the substrate for different conditions of inlet temperature, fuel concentration, and mass flow conditions. In addition, the effect of catalyst length on the temperature profile is illustrated. Emissions measurements are made for the evaluation of the performance of the catalytic reactor under different operating conditions. The conditions required to achieve combustion efficiencies ≥99.5 percent have been experimentally determined. The thermo-mechanical analysis of the support structure of a catalyst element using transpiration cooling has been performed for steady-state conditions. Results show improvements in stress and amount of cooling air required compared to film cooling.
Weak Extinction Limits of Turbulent Heterogeneous Fuel/Air Mixtures
Authors: Ballal D. R. , Lefebvre A. H.
Published: April 2015

Experimental and theoretical studies are made of the factors governing the weak extinction limits of stabilized flames supplied with flowing mixtures of liquid fuel drops and air. The test program includes wide variations in inlet air pressure, velocity and turbulence level, and also covers wide ranges of fuel volatility and mean drop size. The influence of flameholder size and blockage is also examined. An equation is derived for predicting weak extinction limits which shows good agreement with the corresponding experimental values.
DD-963 Class Waste Heat Recovery System Experience
Authors: Graf T. E. , Nagengast J. E.
Published: April 2015

The DD-963 Class ships are the first U.S. Navy vessels to utilize a waste heat recovery system on a gas turbine engine. This paper will present the experience gained from the three years of shipboard operation with the system. The experience will be used to develop areas for consideration that can improve the probability of success in future system procurements. The areas to be considered are: (a) the need for definitive military specifications; (b) the need to test at Navy laboratories and (c) the need to test complete systems under simulated shipboard conditions.
The Application of Indirectly Fired Open Cycle Gas Turbine Systems Utilizing Atmospheric Pressure Fluidized Bed Combustors to Industrial Cogeneration Situations
Authors: Marksberry C. L. , Lindahl B. C.
Published: April 2015

The Atmospheric Fluidized Bed Combustor (AFBC) can utilize a wide variety of solid fuels while meeting strict emission standards. Combined with in-bed and flue gas heat exchangers, an AFBC fired system is compatible with the needs and requirements of industrial plants which have process fluid energy usage rates as low as 5,000,000 Btu/hr. The physical size of components, the technological data base, and capital investment costs are such that the AFBC is a credible alternative for both new and retrofitted plant processes. As a result, AFBC fired process air and process steam systems are now commercially available. By combining an AFBC process air heater with an Open Cycle Gas Turbine (OGT), the indirectly heated clean air can provide plant electrical power, hot process streams, as well as space heat if needed. The cogeneration configuration can increase the rate of return on the AFBC investment and can lead to more efficient utilization of national energy resources. In this paper, the AFBC-OGT cogeneration configuration is reviewed and compared with AFBC-steam turbine configurations and with the AFBC fired process heater in an industrial plant environment.
Engine Evaluation of a Vibration Damping Treatment for Inlet Guide Vanes
Authors: Henderson J. P. , Parin M. L. , Rogers L. C. , Paul D. B.
Published: April 2015

Welded titanium inlet guide vanes in an Air Force turbojet engine, have been experiencing a high rate of vibration induced cracking after very short service The cause of this cracking has been identified as resonant vibration excited by pressure fluctuations occurring when the first-stage fan blades pass the inlet guide vanes A bonded vibration damping wrap has provided a cost effective fix which can be applied on a retrofit basis for major cost savings The damping wrap, which consists of multiple layers of energy dissipating adhesives separated by constraining layers of aluminum foil, is bonded to the vanes under high temperature and pressure in an autoclave. This paper describes the results of engine test-cell tests and the comparison of these results with actual service experience obtained under operational conditions Measured effects on engine performance, distortion tolerance, and anti-icing performance are presented along with measured stress reductions, as compared with increases in modal damping. Durability design considerations are discussed, along with the results of durability tests in an engine test stand and actual service experience.
The Growth and Evolution of the TPE331
Authors: Frignac J.-P. , Privoznik E. J.
Published: April 2015

This paper describes the evolution of the Garrett-AiResearch TPE331 turboprop engine. It discusses the reasoning behind the original design and describes the subsequent growth of the engine from 575 to 1040 hp within the same engine frame size. The performance of the various models and the design features that provided minimum fuel consumption and maximum reliability are also discussed.
The Effect of a Sample Lot of Fuel JECTORS on Emissions Levels of a Small Gas Turbine
Authors: Opdyke George
Published: April 2015

A single small gas turbine engine, containing an annular combustor producing nearly conventional emission levels, was sampled for gaseous emissions and smoke a total of 20 times in a one month period. Five samples each of two fuel injector designs were tested in random order, and the combustor angular orientation was varied with respect to the compressor. In addition to the basic tests with aviation kerosene fuel, emission measurements were also made with Avgas and diesel fuel with each injector design. Fuel spray drop size distributions were estimated from sample test data. The result of changing the fuel injectors was the production of a significant variation in hydrocarbon and carbon monoxide emissions, with limited variation in oxides of nitrogen and smoke. After correction for ambient and operating conditions. the standard deviation in the EPA parameter for hydrocarbons was about 30 percent of the average value and 15 percent of the average value for carbon monoxide. It was postulated that the variation was caused by fuel injector manufacturing tolerances which resulted in large variations in the maximum drop size in individual sprays causing variable entrapment of unvaporized drops in the wall cooling film. The conclusion is that small and perhaps non-detectable variations in injectors can cause changes in emissions from gas turbines, and, in particular, from small gas turbines.
Pressurized Fluidized Bed Coal Combustion Exposure Testing of Gas Turbine and Heat Exchanger Materials
Authors: Nutkis M. S.
Published: April 2015

The Exxon Research pressurized fluidized bed coal combustion pilot plant, known as the miniplant, has been in operation since 1974. Constructed under EPA contract, this facility operates at pressures to 10 atm, bed velocities to 10 ft/sec and temperatures to 1800 F. It can burn 400 lb of coal per hour and has operated for over 2500 test hours. Under a program sponsored by the U. S. Department of Energy, the Exxon pressurized fluidized bed coal combustion miniplant provided a test site and environment for the exposure of specimens of potential PFBCC fireside heat exchanger alloys and gas turbine materials. The intent of these PFBCC exposure tests is to compile a suitable engineering data base for the characterization of the corrosion/erosion behavior of a number of commercially available alloys when exposed to a pressurized fluidized bed coal combustion environment. These PFBCC exposures will provide corrosion/erosion data and comparisons of materials for application to advanced gas turbine/combined cycle type power systems using coal.
A Partial Oxidation Staging Concept for Gas Turbines Using Broadened Specification Fuels
Authors: Clayton R. M.
Published: April 2015

A concept is described for using a very fuel-rich partial oxidation process as the first stage of a two-stage combustion system for onboard processing of broadened specification fuels to improve their combustion characteristics. Results of an initial step in the experimental verification of the concept are presented, where the basic benefits of H2 enrichment are shown to provide extended lean-combustion limits and permit simultaneous achievement of ultralow levels of NOx, CO, and HC emissions. The H2 required to obtain these results is within the range available from a partial oxidation precombustion stage. Operation of a catalytic partial oxidation reactor using a conventional aviation turbine fuel (JP5) and an unconventional fuel (blend of JP5/xylene) is shown to produce a “fuel gas” stream with near-theoretical equilibrium H2 content. However, a number of design considerations indicate that the precombustion stage should be incorporated as a thermal reaction.
Electrocoalescer Comparison Performance Tests
Authors: Prem L. L. , Williams W. R.
Published: April 2015

Validation tests were carried out based upon tests specified in Military Specification MIL-F-8901. The Electrocoalescer has demonstrated excellent performance, has passed the validation test, and showed an improved performance over that of the Military Standard Filter Separator. When tested with diesel fuel, the improvement was on the order of a factor of 10 or more. Moreover, it demonstrated a lower overall pressure drop. Use of the Electrocoalescer in fuels decontamination service is expected to result in cleaner fuels and longer filter life.
The Combustion of a Range of Distillate Fuels in Small Gas Turbine Engines
Authors: Carr E.
Published: April 2015

A compact engine configuration is obtained on small gas turbine engines by the use of a reverse flow annular combustion system. Such combustion systems are usually of narrow width and of relatively large flame tube surface area/volume ratio. In consequence, there is a tendency for excessive concentrations of fuel near to the flame tube internal surfaces and fuel impingement on the flame tube which can give rise to performance deficiencies, such as carbon build, loss of efficiency at low load conditions, smoke, and metal overheating particularly with fuels similar to ASTM D 975 Type 2-D diesel. Since there is an increasing requirement for engines to operate with such heavier fuels, research and development programs were initiated to evolve an improved combustion system. The paper briefly describes the main features of these work programs and outlines the configuration evolved and the performance achieved. An arrangement has been obtained which gives a high standard of performance with fuels ranging from aviation kerosene fuel to gas oil and marine diesel.
Improving Turbine Component Efficiency
Authors: Mach K. D.
Published: April 2015

The thermal efficiency of a gas turbine engine depends on the cycle pressure and temperature ratio and on the aerodynamic efficiencies of the gas path components. Maintaining and/or improving structural integrity and aerodynamic efficiency in this high pressure, high temperature environment is the preeminent problem of the turbine designer. High gas temperatures require at least some of the metal structures to be cooled, yet cooling air is a loss to the cycle and its consumption must be kept to a minimum. Research into cooling techniques and boundary layer behavior on airfoils and endwalls and into test procedures for obtaining heat transfer data are providing some of the answers the designer needs. Increased operating pressures generate increased mechanical stresses. Finite element analyses and automated design procedures are proving to be powerful aids to the designer. Improving aerodynamic efficiency requires careful control of the flow in three dimensions, particularly in low aspect ratio machines. The first practical computation method for three-dimensional, viscous, transonic flows became available in late 1977 and has made this one of the most exciting areas of turbine technology. Additional gains in aerodynamic efficiency can be realized by controlling leakages, especially those over the rotor tip, by accounting for the transient interactions between rotor and stator and by careful control of discharged coolant flow. This paper briefly describes the turbine cooling research conducted by the Air Force Aero Propulsion Laboratory and describes mor extensively the AFAPL programs in turbine aerodynamics, including applications of three-dimensional flow analysis.
Practical “On-Engine” Microprocessor Control and Monitoring Systems for Gas Turbines
Authors: Justice N. A.
Published: April 2015

With the widespread use of microprocessors, new applications are being accepted into gas turbine control and monitoring systems where their capabilities are being tested and proved while in the most arduous physical location — “on the engine.” Some practical guidelines and arguments are given in establishing the criteria for use in these applications and environments.
Environmental Assessment of Advanced Open Cycle Gas Turbine Power Plants
Authors: Cerkanowicz A. E. , Shaw H. , Stevens J. G.
Published: April 2015

The potential environmental problems associated with unrecuperated and recuperated advanced open-cycle gas turbine power plants were analyzed. Such plants, operated with improved high temperature technology (1478 K turbine inlet temperature), achieve 30 to 40 percent cycle efficiencies. The major environmental concerns are associated with NOx emissions resulting from combustor operating practice. Uncontrolled systems were determined to greatly exceed the proposed gas turbine NOx emission standard of 75 cm3/m3 at 15 percent O2 (dry), even when corrected for improved efficiency. Consideration is given to control options which include water injection, catalytic combustion, and combustion modifications (staging). Results indicate the limitations of water injection in comparison with the other control approaches. It was found that uncontrolled NOx emissions could be reduced by about 80 percent with water addition, and in excess of 98 percent with catalytic combustion.
Heavy Duty Gas Turbine Design Changes for Use With Low Btu Coal Gas
Authors: Boothe W. A. , Mcmullen J. C.
Published: April 2015

An MS5000 gas turbine is now being redesigned for integrated operation on low Btu Lurgi coal gas in the Powerton Gasification Combined Cycle Test Facility. Air is extracted from the machine to provide process air for the gasifiers, and a heat recovery steam generator provides steam for the gas plant. This paper describes the design modifications to the gas turbine and its control system to accommodate such operation. Since the facility will demonstrate operation in a variety of control modes using gas produced from a wide range of domestic coals, the gas turbine control system emphasizes flexibility and incorporates several functions unique to low Btu gas applications. Major modifications to the fuel and combustion systems are also required. Test results on the resulting new combustor design are reported in a companion paper (1).
Alternate Ways of Using Bottoming Cycle Power in Pipeline Gas Compressor Stations
Authors: Rossbach R. J.
Published: April 2015

The General Electric Company is carrying out a design study and evaluation of bottoming cycles for gas pipeline compressor prime movers. Three sites were chosen for the study of demonstration organic bottoming cycles of about 5000 hp applied to three aircraft derivative gas turbines of approximately the same size. The purpose of the study is to design and evaluate all important aspects of installing organic bottoming cycle systems on a selected group of gas turbine prime movers driving gas compressors. As a result of the study, it was found that pipeline bottoming cycles applied to gas turbine prime movers could reduce the heat rate 35 percent more than the Department of Energy target value of 20 percent. Installation designs for three sites are described.
Closed Cycle Gas Turbines: An ECAS Update — Part 1
Authors: Daudet H. C. , Kinney C. A.
Published: April 2015

This paper presents a discussion of the significant results of a study program conducted for the Department of Energy to evaluate the potential for closed cycle gas turbines and the associated combustion heater systems for use in coal fired public utility power plants. Two specific problem areas were addressed: (a) the identification and analysis of system concepts which offer high overall plant efficiency consistent with low cost of electricity (COE) from coal-pile-to-bus-bar, and (b) the identification and conceptual design of combustor/heat exchanger concepts compatible for use as the cycle gas primary heater for those plant systems. The study guidelines were based directly upon the ground rules established for the ECAS studies to facilitate comparison of study results. Included is a discussion of a unique computer model approach to accomplish the system analysis and parametric studies performed to evaluate entire closed cycle gas turbine utility power plants with and without Rankine bottoming cycles. Both atmospheric fluidized bed and radiant/convective combustor /heat exchanger systems were addressed. Each incorporated metallic or ceramic heat exchanger technology. The work culminated in conceptual designs of complete coal fired, closed cycle gas turbine power plants. Critical component technology assessment and cost and performance estimates for the plants are also discussed.
A Low Cost, On-Site Performance Monitoring System
Authors: Saravanamuttoo H. I. H.
Published: April 2015

A simple thermodynamic analysis for on-site performance monitoring of shaft power gas turbines is described. The method is simple, requires minimal extra instrumentation, yet permits the operator to determine the critical cycle parameters of turbine inlet temperature and airflow. Computing requirements can be handled by a programmable calculator at minimum cost. Experimental verification of the system showed very good agreement with engine tests.
Film Cooling From Three Rows of Holes on Adiabatic, Constant Heat Flux and Isothermal Surfaces in the Presence of Variable Free-Stream Velocity Gradients and Turbulence Intensity
Authors: Brown A. , Saluja C. L.
Published: April 2015

In this article the influence on film cooling effectiveness of injection from rows of holes into free streams regions with favorable, zero and adverse pressure gradients and turbulence intensities of 0.02 and 0.09 are shown. The effect of the presence of rows of holes on heat transfer from a surface is shown and the increase of heat transfer due to injection through the rows of holes for both isothermal and constant heat flux surfaces is measured.
Heat Transfer to Turbine Blades, With Special Reference to the Effects of Mainstream Turbulence
Authors: Brown A. , Martin B. W.
Published: April 2015

The mainly empirical criteria used to predict boundary-layer behavior under the combined influence of velocity gradient factor and significant mainstream turbulence are reviewed and assessed by application to recently published blade heat-transfer measurements. Indications are that under the conditions experienced in gas turbine engines, the scale and frequency of mainstream turbulence may be as important as its intensity in determining local heat transfer coefficients round the blades.
Gas Turbine Installation in Naviplane N500
Authors: Oberlaender G. , Guienne P.
Published: April 2015

Designed by SEDAM and built in 1975–1977, the Naviplane N500 hovercraft started the Boulogne-Dover cross-channel service in mid-’78. The craft is powered by five AVCO-Lycoming TF40 gas turbines driving the three propellers and two lift fans and two KHD T216 APU’s for the electric power supply. The engineering of the gas turbines’ installation is the contribution of Klöeckner-Humboldt-Deutz AG (KHD) to the total craft concept of SEDAM. In describing the installation features, the paper’s accent is placed on interface problems, the solutions chosen and the results obtained. These problems include air intake and exhaust systems, silencing, power package suspension and shaft line analyses, fuel and electric power supply and operational control.
Improvement of Nozzle Life in Gas Turbines
Authors: Flowers T. L. , Anderson A. W. , Brunso J.
Published: April 2015

The time between major overhauls of an industrial gas turbine is often determined by the thermal fatigue life of the first stage turbine nozzle. The thermal fatigue cracking results from thermal strains induced by the temperature transients and the resulting thermal gradients within the nozzle assembly. This paper discusses a joint GE/ARAMCO development program undertaken in order to investigate the causes of these gradients and to develop means to reduce the magnitudes and the number of occurrences in a MS5002A industrial gas turbine.
Unsteady Upstream Effects in Axial-Flow Supersonic Compressor Stages
Authors: Gallus H. E. , Bohn D. , Broichhausen K.-D.
Published: April 2015

An investigation of the unsteady flow effects in a supersonic compressor stage is reported. Semiconductor transducers mounted in the casing, a stroboscopic schlieren-technique and probes equipped with semiconductor transducers were used to obtain unsteady static pressure, flow visualization and three-dimensional flow information, respectively. The throttling effect during the starting procedure of the stage was found to produce changes of the quasi-steady and unsteady rotor flow pattern as well as changes in both amplitude and frequency of the flow disturbances at the inlet. The conditions which are generated in this way at design speed are different from those reached by back-pressure imposed on the started supersonic rotor at the same speed. The relative position of rotor and stator has an influence on the flow field only below design speed. One can conclude from the measurements of the rotor outlet angle that these effects generated by throttling the rotor flow by a stator during the starting procedure might be avoided with movable stator blades.
Development of a Ceramic Heat Exchanger for a Closed-Cycle Gas Turbine Engine
Authors: Coombs M. G.
Published: April 2015

This paper describes the development of a silicon carbide heat exchanger for the CCPS-40-1 closed-cycle gas turbine engine. This effort was part of a program to explore the use of closed-cycle power systems for utilities. The program consists of heat exchanger design, the development of a design approach for large ceramic components, the establishment of a material data base, and the development of the required fabrication technology. Small-scale ceramic heat exchangers were operated at material temperatures up to 2300 F.
Feasibility of an Isolated Reverse Turbine Concept for Marine Propulsion
Authors: Bowen T. L.
Published: April 2015

The feasibility of an isolated reverse turbine concept for marine propulsion was examined with emphasis on (1) the reverse turbine size needed to meet the stopping distance requirement of a particular ship during a crashback maneuver, and (2) the ahead turbine performance penalty due to reverse turbine windage losses. This particular reverse turbine system was made adaptable to the exhaust elbow and output shaft of an existing free-power-turbine gas turbine. The analysis was based on the application of this reverse turbine concept to a notational single-shaft frigate. The study-ship’s propulsion system includes two General Electric LM2500 gas turbines with reversing capability, a reduction gear, and a fixed-pitch propeller. A ship propulsion simulation was developed for the purpose of calculating steady-state ahead and backing performance data, as well as transient behavior of the ship during crashback maneuvers. The reverse turbine’s speed and torque required to stop the ship in five ship-lengths and 3.5 ship-lengths were determined from these calculations. Four reverse turbine designs were generated using a computer program for preliminary design of axial-flow turbines. The designs included a single-stage and a two-stage impulse turbine for both stopping distances. The penalty on ahead performance due to reverse turbine windage was estimated for each design, using existing experimental data found in the literature. The results obtained thus far tend to support the feasibility of this reverse turbine concept.
Investigation of the Heat Transfer in Cylindrical Receiver Configurations With Inner Tubes
Authors: Bammert K. , Krapp R. , Seifert P.
Published: April 2015

The design of a receiver for a closed-cycle gas turbine with air as the working medium is discussed. The emphasis of the investigations is layed upon the optimization of heat transfer to the working medium. The irradiation pattern along the tubes and the effects of the working-medium pressure, the pressure loss and the tube cage geometry are considered.