bluuebunny/crossref_metadata_2025 huggingface dataset:
Air Flow Performance of Air Swirlers for Gas Turbine Fuel Nozzles
Authors: Martin Charles A.
Published: March 2015

Swirlers are very important elements of gas turbine combustion systems, necessary for the proper operation of a modern gas turbine engine.

In this paper the performance of air swirlers with a range of swirl angles and diameters are examined and discussed in the context of recently published papers. Parameters which are included in this discussion are swirl number, swirler thrust, swirler torque, swirler solidity, etc.

Results suggest that swirler “see through” is not necessarily bad, but may be beneficial with respect to swirl number and other parameters. The use of a mean swirler radius to calculate the swirl number and the resulting benefits are discussed and demonstrated.
Ongoing Development of a Gas Turbine Combustion System for Gaseous Fuels With a Wide Range of Wobbe Index Values
Authors: Sood V. M.
Published: March 2015

Development of a combustion system at the author’s Company was carried out at atmospheric pressure to achieve successful operation of a 5500-hp (Type H) gas turbine on gaseous fuels covering a wide range of Wobbe Index (WI) values from 48.04 MJ/nm3 (1220 Btu/scf) for natural gas to 18.90 MJ/nm3 (480 Btu/scf) for natural gas and carbon dioxide mixtures. Mixtures with the latter composition have direct applications for gas turbine engines burning fuels derived from sanitary landfills and liquid sewage. Wide-range operational capability offers the flexibility to fire gas turbines with either pipeline quality natural gas or medium-heating-value fuel, depending on availability. For such applications, if a fuel injector is designed to operate satisfactorily on natural gas fuel, it will have unacceptably high pressure drops when operating on fuels with WI values towards the lower end of the range. On the other hand, if the fuel injector is designed to operate properly on fuels with WI values on the lower end of the range, it will have unacceptably low pressure drops when operating on fuels with WI values towards the higher end of the range, which causes combustion-driven pressure oscillation feedback into the fuel-injection system. This feedback usually increases the amplitude of combustion-driven pressure oscillation and can cause significant damage to the gas turbine in a relatively short time.

This paper describes the design and development work carried out to resolve these problems.
Gas Turbine Studies at Oxford 1969–1987
Authors: Jones T. V.
Published: March 2015

Gas turbine heat transfer studies commenced at Oxford University in 1969 when transient techniques previously used for measurements in hypersonic flows were applied to the gas turbine environment. Shock tubes were employed and subsequently a new form of transient tunnel, the Isentropic Light Piston Tunnel, was developed specifically for turbine heat transfer testing. During the following years further short duration facilities were developed to study blade and vane external aerodynamics and also the heat transfer in cooling passages was examined using liquid crystal techniques. All these transient facilities are described and the development of the instrumentation peculiar to these is explained. The results of the work on external and internal heat transfer are summarised. In particular, the film cooling studies, the blade and vane external heat transfer work and the wake simulation experiments are outlined. This paper is dedicated to the late Don Schultz.
Progress on Measurement Techniques for Industrial Gas Turbine Technology
Authors: Valentini E. , Lacitignola P. , Casini M.
Published: March 2015

Instrumentation and measurements play a very special role in the advancement of gas turbine turbomachinery. In an industrial gas turbine experimental program, testing constantly flanks machine development and full-load testing of extensively instrumented units provides information on both overall and component performance.

Rotordynamic testing is performed to determine, in ambient conditions, the optimum configuration for the rotor-bearing-casing assembly.

Fluid-dynamic testing on models of the inlet duct, turbine casing and transition piece assembly and blade cooling system is carried out to minimize flow distortions or optimize cooling flows.

Stress and modal analyses on turbine and compressor blades are performed, using 3D photoelasticity and holographic interferometry.

In the full-load testing, the measurements include thermodynamic values, temperatures of the components, blade vibratory strains, blade tip clearances and axial displacements.

Signals from rotating thermocouples and strain gages, installed on both turbine and compressor rotors, are transmitted using slip ring systems. HP blade temperature distribution is measured by means of the infrared pyrometer.

Typical Campbell diagrams are derived from the blade strain gage measurements and are used for HCF verification.

Radial and axial stator-to-rotor displacements are measured during transients.
An Emissions Database for U.S. Navy and Air Force Aircraft Engines
Authors: Faulkner Henry B. , Platt Melvin , Klarman Anthony F. , Smith Mark D.
Published: March 2015

Within the U. S., the pollutant emissions at Navy and Air Force airbases are not regulated by civil law. However, there is a desire to be a good neighbor to the local population. On the other hand, military engine test facilities are designated as ground emission sources which are subject to civil air quality regulations. Both situations contribute to a Navy and Air Force requirement for the generation of air quality scenarios, which in turn requires ready access to engine emissions data.

A considerable body of emissions data has been collected for U. S. military aircraft engines over the last twenty years. However, this data is not readily accessible, because it is distributed in a variety of technical publications, and is not presented in a consistent format.

Therefore the Navy, with Air Force cooperation, has sponsored a program to develop an engine emissions database system tailored to their requirements, for use on a microcomputer. The program was conducted by Northern Research and Engineering Corporation. The resulting database contains all of the available emissions data, as well as background information on each engine model and the conditions for each test. All of the unclassified operational engine models of the Navy and Air Force are listed, whether or not emissions data are available. When emissions data is not available for a particular model, but there is a similar engine model whose data can reasonably be substituted, this is identified. The system provides an easy and versatile means of accessing the available emissions data. In general, the computerized database approach can increase the value of many types of experimental data.
Periodicity, Superposition, and 3D Effects in Supersonic Compressor Flutter Aerodynamics
Authors: Gerolymos G. A.
Published: March 2015

In this work, a family of methods, both blade-to-blade surface and 3D, based on the numerical integration of the unsteady Euler equations, are used in studying various aspects of the unsteady aerodynamics of vibrating compressor cascades, in the supersonic flutter region. Most aerodynamic methods assume a traveling wave assembly mode of structural vibration, and suppose that the associated chorochronical periodicity is also encountered in the flowfield. This hypothesis has been tested by simulating the flow in a full annular cascade and has been verified in all the cases we have studied. When analyzing the aeroelastic stability of cascades, some assembly modal basis must be used. This, especially in presence of mistuning, relies on modal superposition hypotheses and linearity assumptions. The superposition assumption seems to be justified and the linear range of the amplitude-response is fairly large, although it varies greatly with frequency. Finally, an assessment of the importance of unsteady 3D effects is attempted using the 3D method.
The Design of a 3MW Kalina Cycle Experimental Plant
Authors: Kalina A. I. , Leibowitz H. M.
Published: March 2015

An experimental project is now underway to demonstrate the advantages of the Kalina cycle technology. A Kalina Cycle Experimental Plant (KCEP) will be built as a 3 MW bottoming cycle using the waste heat from a facility within the Energy Technology Engineering Center (ETEC), a U.S. Department of Energy laboratory located in Canoga Park, California.

The design of the experimental plant is presented, including the process flow diagram, heat and mass balance, and specifications for the plant’s major equipment; the waste heat boiler, turbine generator and distillation/condensation subsystem.

Using a mixture of ammonia and water at a mass ratio of 70/30, and a new condenser design based on absorption principles, the Kalina cycle plant will attempt to demonstrate its superiority over the Rankine steam cycle. Based on single pressure designs at comparable peak cycle temperatures, the Kalina cycle’s output should exceed that of the steam cycle by 25 percent.
Second Sourcing of a Jet Engine
Authors: Hix Jimmy
Published: March 2015

The U.S. Navy’s desire to establish a competitive second source for its newest fighter engine compelled the USN to develop Pratt & Whitney as an alternate manufacturer of the F404-GE-400 afterburning turbofan jet engine. This paper describes in detail the process of developing a “build to print” alternate manufacturing source which does not have access to the original design agent. It further describes the trials, triumphs, and lessons learned in the case history.

The specifics which are described in the paper are: the validation of the U.S. Navy’s data procurement policies, the strength of its procuring agencies, the key decisions leading to the end results, the vital roles played by specific U.S. Government agencies in the process, the engineering methods used in transferring unfamiliar data sets into the manufacturing of all facets of a jet engine, the engineering process used to substantiate the manufacturing processes, the source qualification process, the quality assurance methods used to implement unfamiliar quality control requirements, the overall benefits to industry and the U.S. Government, and the long term implications of this effort to the U.S. Government Department of Defense procurement process.
Effect of Free-Stream Turbulence, Reynolds Number, and Incidence on Axial Turbine Cascade Performance
Authors: Vijayaraghavan S. B. , Kavanagh P.
Published: March 2015

A large-scale, low-speed, axial turbine cascade designed for high-loading and high-turning was tested over a range of Reynolds number, turbulence level, and incidence angle. End wall suction was applied to provide two-dimensional flow over a large spanwise region of the airfoil. In all, thirty-six test conditions were examined.

Overall cascade performance including mass-averaged loss coefficients at each test flow condition was determined from detailed five-hole pressure probe traverses in an exit plane of the cascade. In addition, using glue-on hot-film gages and surface oil-flow visualizations, transition and/or separation was identified over the suction surface of the airfoil. The measured transition start and end points were compared against predictions using existing transition models. Also, the measured losses were compared against predicted losses from boundary layer calculations based on finite difference analysis.
Design of a 50 MW Pilot Plant for a High Efficiency Steam Cycle
Authors: Perz E. , Gasteiger G. , Steinrück P. , Mader O. , Jericha H.
Published: March 2015

A novel steam cycle promises reasonable efficiency gains compared with conventional cycles. The efficiency gains are achieved with a double water/steam loop, enabling high temperatures of heat input. To check the operability of the cycle, a feasibility study for a 50 MW pilot plant has been carried out. This paper gives a survey of the thermodynamics of the pilot plant followed by results achieved for two of the most crucial components, the steam heater and the high temperature turbine.
Detailed Heat Transfer Measurements Near and Within the Entrance of a Film Cooling Hole
Authors: Byerley A. R. , Ireland P. T. , Jones T. V. , Ashton S. A.
Published: March 2015

An experimental investigation was conducted to obtain highly detailed convective heat transfer measurements on an internal cooling duct wall around the entrance to a film cooling hole. Measurements were also made within the first five diameters of the film cooling hole. Thermochromic liquid crystals were used as surface temperature indicators in a large scale, perspex tunnel during the transient tests. A single film cooling hole was installed perpendicular to the main duct in a region of two-dimensional, fully developed turbulent flow. The main duct wall thermal boundary condition closely approximated an isothermal situation. The duct Reynolds number was held constant at a value characteristic of actual engine conditions while the ratio of the mean axial hole velocity to the duct centreline velocity was varied systematically between 0 and 8.0. The results are presented as contours of heat transfer coefficient normalized by that for the plain duct wall. Significant enhancement on the duct wall was measured up to a distance of seven hole diameters downstream of the hole. Both the magnitude and the shape of the enhancement contours were found to be highly dependent on the hole-to-duct velocity ratio.
Development of a Thermal and Structural Analysis Procedure for Cooled Radial Turbines
Authors: Kumar Ganesh N. , Deanna Russell G.
Published: March 2015

A procedure for computing the rotor temperature and stress distributions in a cooled radial turbine is considered. Existing codes for modeling the external mainstream flow and the internal cooling flow are used to compute boundary conditions for the heat transfer and stress analyses. An inviscid, quasi three-dimensional code computes the external free stream velocity. The external velocity is then used in a boundary layer analysis to compute the external heat transfer coefficients. Coolant temperatures are computed by a viscous one-dimensional internal flow code for the momentum and energy equation. These boundary conditions are input to a three-dimensional heat conduction code for calculation of rotor temperatures. The rotor stress distribution may be determined for the given thermal, pressure and centrifugal loading. The procedure is applied to a cooled radial turbine which will be tested at the NASA Lewis Research Center. Representative results from this case are included.
A Comparison of the Transient and Heated-Coating Methods for the Measurement of Local Heat Transfer Coefficients on a Pin Fin
Authors: Baughn J. W. , Ireland P. T. , Jones T. V. , Saniei N.
Published: March 2015

Measurements of the local heat transfer coefficients on a pin fin (i.e., a short cylinder in crossflow) in a duct have been made using two methods, both of which employ liquid crystals to map an isotherm on the surface. The transient method uses the liquid crystal to determine the transient response of the surface temperature to a change in the fluid temperature. The local heat transfer coefficient is determined from the surface response time and the thermal properties of the substrate. The heated-coating method uses an electrically heated coating (vacuum-deposited gold in this case) to provide a uniform heat flux while the liquid crystal is used to locate an isotherm on the surface. The two methods compare well, especially the value obtained near the center stagnation point of the pin fin where the difference in the thermal boundary condition of the two methods has little effect. They are close but differ somewhat in other regions.
Effect of Shock Wave Movement on Aerodynamic Instability of Annular Cascade Oscillating in Transonic Flow
Authors: Kobayashi Hiroshi
Published: March 2015

Effects attributable to shock wave movement on cascade flutter were examined for both turbine and compressor blade rows, using a controlled-oscillating annular cascade test facility and a method for accurately measuring time-variant pressures on blade surfaces. Nature of the effects and blade surface extent influenced by the shock movement were clarified in a wide range of Mach number, reduced frequency and interblade phase angle. Remarkable unsteady aerodynamic force was generated by the shock movement and it significantly affected the occurrence of compressor cascade flutter as well as turbine one. For turbine cascade the interblade phase angle remarkably controlled the effect of the force, while for compressor one the reduced frequency dominated it. The chordwise extent on blade surface influenced by the shock movement was suggested to be about 6% chord length.
An Experimental Investigation Into the Influence of Blade Leaning on the Losses Downstream of Annular Cascades With a Small Diameter-Height Ratio
Authors: Wanjin Han , Zhongqi Wang , Wenyuan Xu
Published: March 2015

Five types of cascades with different leaned blades have been tested in a low speed annular cascade tunnel. The experimental results show that by using positively leaned blades the hub wall boundary layer in cascade passage can be sucked into main stream zone, and the amount of low energy gas getting into downstream of the cascade is reduced obviously, so that the energy losses downstream is decreased considerably.
Effect of Coal Constituents on the Liquid-Assisted Capture of Impacting Ash Particles in Direct Coal-Fired Gas Turbines
Authors: Nagarajan R. , Anderson R. J.
Published: March 2015

With the growing interest in burning pulverized coal directly in gas turbines, the problem of fouling — blockage of hot-gas pathways by thick ash deposits — is receiving increased attention. The inertial deposition rate of supermicron ash, which determines the fouling propensity of the coal via the thickness of the deposit, depends linearly on the sticking fraction of ash material arriving at the cooled surfaces, e.g., turbine blades and guide vanes. The magnitude and temperature-dependence of the sticking coefficient will depend on the inventory, composition and physicochemical properties of the liquid ‘glue’ consistent with the prevailing temperature, pressure and trace inorganic elemental compositions. As the deposit evolves in time, it encounters several deposition regimes in the order of increasing surface temperature, each characterized by a different source of liquid glue. The effect of coal-ash constituents on the extent of each of these sticking regimes is investigated theoretically here by means of a model of ‘self-regulated’ ash deposition.
Salt Ingestion Test of the AGT 1500 Recuperated Automotive Gas Turbine
Authors: Bodman Thomas M. , Priore Thomas P.
Published: March 2015

A salt ingestion test was performed on the AGT 1500 recuperated automotive gas turbine engine at the Naval Ship Systems Engineering Station (NAVSSES) for the U.S. Marine Corps. The Marine Corps was concerned about the AGT 1500’s ability to tolerate their amphibious and maritime environments. The AGT 1500 was operated for two 450 hour endurance runs burning Navy diesel fuel and ingesting aerosol salt. It suffered no failures or significant loss of power as a result of the ingested salt or operations with Navy diesel fuel.
Thermomechanical Advances for Small Gas Turbine Engines: Present Capabilities and Future Direction in Gas Generator Designs
Authors: Propen M. , Vogel H. , Aksoy S.
Published: March 2015

Performance requirements of tomorrow’s gas turbines demand major improvements in specific fuel consumption and thrust to weight ratio. These stringent requirements, in turn, drive the need for higher operating temperatures and lighter weight engines.

Such technical improvements impose severe thermal, structural, and metallurgical demands upon turbine components. A broad spectrum of technology programs is underway at Textron Lycoming to address these challenging requirements. This paper outlines the thermal, structural, and materials research needed for achieving the goals of the small gas turbines of tomorrow.
Analysis of Efficiency Sensitivity Associated With Tip Clearance in Axial Flow Compressors
Authors: Moyle Ian N.
Published: March 2015

The effects of tip clearance changes on efficiency in axial compressors are typically established experimentally. The ratio of change of efficiency with change of clearance gap varies significantly for different compressors in the published data. An analysis of this sensitivity range in terms of the blade and stage design parameters was initiated. The analysis revealed that the sensitivity range largely resulted from a derivation at constant flow of the efficiency decrement. It was also found that a generalized loss method of generating the sensitivities produced a much improved correlation of the change in efficiency with change in clearance over a variety of machines, configurations and speeds.
Computation of the Jet-Wake Flow Structure in a Low Speed Centrifugal Impeller
Authors: Lapworth B. L. , Elder R. L.
Published: March 2015

The low speed flow through the shrouded de-Havilland Ghost centrifugal impeller is computed using an incompressible elliptic calculation procedure. The three dimensional viscous flow equations are solved using the SIMPLE algorithm in an arbitrary generalised coordinate system. A non-staggered grid arrangement is implemented in which pressure oscillations are eliminated using an amended pressure correction scheme. Flow computations are performed at ‘nominal’ low speed design and above design flow rates, and (on the coarse grids used in the calculations) good agreement is obtained with the experimentally observed jet-wake structure of the flow.
A Comparison Between Measurements and Turbulence Models in a Turbine Cascade Passage
Authors: Zunino Pietro , Ubaldi Marina , Satta Antonio , Peisino Enrico
Published: March 2015

Detailed measurements of mean velocity, turbulence intensity and Reynolds stresses have been performed in the passage of a cascade of turbine rotor blades. By using the experimental values of the mean velocity, the turbulence quantities are computed with three different turbulence closure models. The results are analysed and compared with the experimental data. The capability of the closure models to describe the turbulence development associated with secondary flows in a turbine cascade is discussed.
Precision Error in a Turbofan Engine Monitoring System
Authors: Henry J. R. , Moffatt W. C.
Published: March 2015

In modern aircraft, the use of engine monitoring systems to develop performance trend lines relies upon the systems’ precision (i.e. repeatability). This paper describes an investigation of precision error in the turbofan engine monitoring system of a modern fighter, based on steady state and transient data records. Both the aircraft data acquisition system and a ground-based system of known precision error were used to measure engine-mounted sensor outputs, the result being an estimate of sensor precision. Sensor precisions were also determined based on manufacturers’ specifications. Furthermore, based on steady state and transient aircraft data, a method was devised for estimating overall system precision. From this information, it was concluded that (1) precision errors in sensing are markedly lower than those incurred in conditioning and processing engine data and (2) possible improvements to the monitoring system are constrained by data sampling rates and digital word formats. Precision error intervals for engine data were obtained so that the significance of shifts in engine performance could be assessed.
A Unified Solution Method for the Flow Calculations Along S1 and S2 Stream Surfaces Used for the Computer-Aided Design of Centrifugal Compressor
Authors: Qinghuan Wang , Haoyu Yu
Published: March 2015

In order to facilitate the aerodynamic design for the computer-aided design (CAD) of centrifugal compressor, a unified direct problem method for the flow calculations along S1 and S2 stream surfaces has been presented in the present paper. A single stream function equation expressed by nonorthogonal curvilinear coordinates and the unified matrix direct solution for the governing equation have been used. This method greatly simplifed the quasi-three dimensional and full dimensional computing program, meanwhile it improved the computing accuracy and the convergence rate. Numerical examples have illustrated the advantages of the new technique for CAD of centrifugal compressors.
Diagnostics Development for Spray Characterization in Complex Turbulent Flows
Authors: Bachalo W. D. , Brẽna De La Rosa A. , Rudoff R. C.
Published: March 2015

The present work reports a detailed investigation of air-liquid interaction in sprays along with particle number density and mass flux measurements in complex turbulent flows such as those present in gas turbines and rocket combustors. Data have been obtained for the characterization of sprays in complex flows which include detailed drop size and drop velocity distributions, size-velocity correlations, mass flux, and particle number density. Key factors affecting the measurement of the sample volume size are discussed in detail since an accurate estimation of it is essential to the particle number density and volume flux determined by the instrument. The discrimination of refraction and reflective scattering components and their influence on the measurements is also discussed. Data comparing the phase Doppler results to alternate methods of measuring number density and volume flux are also presented. These results showed agreement to within 15% in most cases for realistic flow configurations.
The Effects of Relative Motion, Blade Edge Radius and Gap Size on the Blade Tip Pressure Distribution in an Annular Turbine Cascade With Clearance
Authors: Morphis G. , Bindon J. P.
Published: March 2015

Flow visualisation and microscopic static pressure measurements were done in the tip clearance region of an annular turbine cascade with a rotating outer casing to simulate the relative motion at the tip of an axial rotor. The effect of relative motion did not have a significant effect on the blade gap pressure distributions. As in previous studies the narrow deep pressure depression on a sharp pressure edge was seen. It was confirmed that the width of the gap separation bubble depends on clearance and a correlation with flow visualisation showed that at the reattachment line there is the expected slight pressure peak. The separation bubble, which is thought to contribute a major part of the leakage loss, was shown to disappear when the pressure surface tip is give a radius of 2.5 gap widths.
Technical Approach for a MultiPurpose Small Power Unit
Authors: Thompson Robert G. , Parker Sidney D.
Published: March 2015

This paper describes the technical approach used to select the engine configuration and performance cycle for a small gas turbine engine. The work was done during the preparation of a proposal to the U.S. Army for an advanced gas-turbine-based MultiPurpose Small Power Unit (MPSPU) in the 50–75 SHP class. Uprating to 100 hp (74.6 kw) with the fewest possible component changes was also desired and will be demonstrated. The proposal was successful, and the resultant engine offering, the T-100 MPSPU, is currently under development.

The performance analyses used to quantify the T-100 MPSPU cycle were unique in that component efficiency correlations were used interactively when estimating performance at high levels of work (or pressure ratio per stage) with relatively small size components.

The MPSPU program goal is to verify gas turbine technology advancements in small engine components, materials and design techniques that will lead to significant reductions in fuel consumption for this size class engine. Successful incorporation of these technologies will lead to significant savings in fuel usage and logistic requirements.
Turbo Expanders for Energy Recovery; Design and Installation of a 250 Kw Unit
Authors: Cleveland A.
Published: March 2015

Turbo expanders have been used in a number of installations to generate electricity from the energy available in the process of pressure reduction. The turbo expander replaces the regulating valve and duplicates the functions of the valve, controlling pressure and flow while at the same time generating electricity.
Laser: A Gas Turbine Combustor Manufacturing Tool
Authors: Sweet E. Jack , Feeley J. Terence
Published: March 2015

Coordination of the latest manufacturing technologies to improve aircraft gas turbine combustor design has resulted in developing processes for machining and welding of combustor liners with laser. Major concerns were the cutting and drilling of chrome nickel alloys and ceramics to result in precise sizing with minimal or no burrs or slag which, if they existed, would disrupt airflow patterns, and welding which would neither contribute to distortion nor leave built-in cracks to propagate in fatigue loading. Laser machining has met these criteria with results superior to those of conventional punching, drilling, and welding techniques.
The Effect of the Reynolds Number on the Three-Dimensional Flow in a Straight Compressor Cascade
Authors: Cyrus Václav
Published: March 2015

A straight compressor cascade of aspect ratio 2 was tested in a low speed tunnel within Reynolds number Re1 = 45 000 – 150 000 and inlet flow angle α1 = 35° – 48°. The profile of the blade was NACA 65-12-10. The purpose of the paper was to obtain data on three–dimensional flow in a straight cascade at low Reynolds numbers. Some experimental results on secondary flow have been made into simple correlation relations.
Thermal Barrier Coatings for Jet Engines
Authors: Toriz F. C. , Thakker A. B. , Gupta S. K.
Published: March 2015

Thermal barrier coatings (TBC) have been used in jet engine combustors for over 15 years. However, it is only recently that they have been actively used in the harsh turbine environment on nozzle guide vane platforms. It is intended to use TBCs on vane airfoils, and on rotating turbine blades where the maximum payoff will be realized. Much work has been done in the last five years towards this goal. Problem areas that need to be addressed are as follows:

1. Prevent coating failure due to:

a. thermal cycling of the ceramic layer.

b. oxidation of the bond coat.

c. erosion due to gas stream solid particles.

d. deposition of gas stream molten debris.

e. acid leaching of coating phase stabilizers.

2. Minimize performance losses due to rough coatings.

3. Insure consistent high quality coatings.

This report will review some of the work done by Rolls-Royce that would hopefully allow an increased use of TBCs on turbine components in the future.
Management of Marine Gasturbines Within the Royal Netherlands Navy
Authors: Crommelin G. A. K. , Kool J. C.
Published: March 2015

This paper will present the latest developments of the marine gasturbine propulsion within the Royal Netherlands Navy. At present the fleet consists of 14 frigates using 2 Olympus and 2 Tynes in a COGOG configuration, and a further 1 minehunters equipped with 3 Astazou 4M gasturbines used as prime movers for alternators.

From the beginning of 1990 the RNLN will start to operate the Spey in the first of the “M” class frigates.

All these ships were designed and built by our own industry. In particular the outcome of trends, that were indicated 4 years ago in the article “Ten years of gasturbine prolulsion in ships of the Royal Netherlands Navy”, ASME paper 84-GT-266, will be highlighted.
The Effects of Gas Velocity and of Temperature on the Oxidative Response of Selected Sheet Superalloys
Authors: Wright J. V. , Leader J. R.
Published: March 2015

The ability of a range of sheet alloys to withstand oxidation has been assesed under static furnace conditions and under dynamic conditions.

It was established that alloys showing considerable promise in the static environment degraded more rapidly during the dynamic burner rig test so that rankings were changed dramatically.

Chromium depletion as a result of volatilisation of oxide species was believed to be responsible. A testing programme was instituted to study the effects of gas velocity and of temperature on oxide stability in Nimonic alloy 86, Haynes alloy 188 and Hastelloy X.

Although the compositions of the alloys and hence of the oxides were complex, reduction in the Cr2O3 content of the oxide layer was observed following high velocity gas stream exposure when temperatures were as low as 750°C. A theory is proposed relating the response of the three alloys to the composition of each of the principal spinels.
Impingement/Effusion Cooling: Overall Wall Heat Transfer
Authors: Andrews G. E. , Asere A. A. , Hussain C. I. , Mkpadi M. C. , Nazari A.
Published: March 2015

Experimental results are presented for the overall heat transfer coefficient within an impingement/effusion wall, using a transient cooling technique. This was previously used for determining the effusion hole heat transfer alone. Two impingement/effusion geometries were used with an 8 mm gap and the same impingement wall with an X/D of 11. The separate impingement and effusion short hole heat transfer coefficients were also determined. The impingement/effusion overall heat transfer was 45% and 30% higher than the impingement heat transfer alone for the two test geometries. The greater increase was for the higher pressure loss effusion wall. It was shown that the combined heat transfer was predominantly the addition of the impingement and effusion heat transfer coefficients but the interaction effects were significant and resulted in an approximately 15% deterioration in the combined heat transfer coefficient. Overall film cooling effectiveness was obtained that showed a significant improvement with the addition of the impingement cooling, but still had a major effusion film cooling contribution.
Low NOx Primary Zones Using Jet Mixing Shear Layer Combustion
Authors: Abdul Hussain U. S. , Andrews G. E. , Cheung W. G. , Shahabadi A. R.
Published: March 2015

An interacting radial and axial multi jet shear layer combustion system is described that has the rapid fuel and air mixing characteristics necessary for low NOx emissions. The radial jet has the fuel mixed with a proportion of the total primary zone flow and a 30% proportion was investigated. This radial jet was fuel rich at most primary zone operating conditions and ensured a flame stability far superior to the premixed situation. The scale up of the design from a 76mm to a 140mm diameter combustor was investigated. It was demonstrated that the distance the radial jet travelled before encountering the rapid mixing with the axial jets, had a strong influence on the combustion efficiency and NOx emissions. For both the 76 and 140mm combustors it was shown that the NOx emissions with propane were 50% greater than those for natural gas. It was also demonstrated that the low NOx emissions of the 76mm system were retained in the larger combustor with the same single central fuel injector design. There was a significant increase in NOx for some 140mm combustor configurations, but the emissions corrected to 15% oxygen below 10ppm were demonstratred, with a high combustion efficiency. The design thus demonstrated, in a practical combustor size, the potential for a dry solution to the NOx emissions problem of natural gas fired industrial gas turbines.
Stratified Charge Rotary Engines for Aircraft
Authors: Mount Robert E. , Guaroa Gaston
Published: March 2015

Substantial progress has been made over the past two years in the technological status and production aspects of Stratified Charge Rotary Engines, a new propulsion technology for aircraft of the 1990’s. A 400 HP aircraft engine, designed in cooperation with Avco-Lycoming (during late 1986) is currently undergoing testing at John Deere’s Rotary Engine Division. Current status and design features are reported in this paper and related to overall research and technology enablement efforts toward several families of advanced liquid cooled, turbocharged and intercooled engines over a wide power range for commercial general aviation. Capabilities for high altitude, long endurance, military unmanned aircraft missions are examined. Application to fixed and rotary wing aircraft are planned.
Navy V/STOL Engine Experience in Altitude Test Facility
Authors: Cunningham William H. , Boytos Joseph F.
Published: March 2015

The Pegasus V/STOL Engine used in the AV-8B/GR MK5 Harrier II Aircraft presents several unique installation requirements for testing in an Altitude Test Facility. These requirements are dictated by the fact that the Pegasus engine has four separate exhaust nozzles, and the short, highly-curved Harrier inlet creates unusual inlet distortion conditions. The Naval Air Propulsion Center has designed and fabricated equipment which has been used to test the Pegasus engine under simulated altitude conditions. During engine testing, problems were encountered with the rear nozzle exhaust collectors and the proposed solutions are presently being implemented. This paper describes the development of the Navy capability to test the Pegasus engine in an uninstalled performance configuration, and with total pressure distortion screens; with aircraft accessories loaded; and with a mock-up of the AV-8B aircraft inlet to determine the effects of combined total and static pressure distortion on engine performance and surge margin.
Gas Turbine Driven Reciprocating Compressors for a Natural Gas Storage Plant
Authors: Urban Martin , Andrée Hubert
Published: March 2015

A major expansion phase is underway at the Ruhrgas natural gas storage plant at Epe on the border between West Germany and the Netherlands. The plant already has 8 caverns with a total working capacity of approx. 350 × 106 m3 (n). 28 caverns are to be added, to bring the total to approx. 1.0 × 109 m3 (n). In view of the increase in capacity, it was necessary to raise the power installed for driving gas compressors from the existing figure of approx. 3,000 kW to a total of 12,000 kW in phase II. A minimum of 2 units were required for this figure of 9,000 kW.

Epe is already the second largest natural gas storage facility in West Germany and is designed to store both low BTU and high BTU natural gas. The facilities are operated at a wide range of pressures and flow rates. The new compressor units will be used only for gas injection at well head pressures of up to 200 bar.
On the Optimal Location and Number of Intercoolers in a Real Compression Process
Authors: Vadasz Peter , Pugatsch Jossef , Weiner Dan
Published: March 2015

In this paper the optimal location and number of intercoolers in a real compression process, including pressure losses, is derived by minimizing the compression specific work. Consequently the series of intermediate pressure values where the system intercoolers should be located is evaluated. As a result a solution different from the classical-isothermal compression process is obtained. The ideal process is evaluated and verified as a particular case by assuming no pressure losses. In reality, minimizing the compression work is only a partial criterion of optimization and the final decision regarding the optimal number of intercoolers should be obtained by using techno-economic criteria.
Steam Injection of Frame 5 Gas Turbines for Power Augmentation in Cogeneration Service
Authors: Little David A. , Rives J. P.
Published: March 2015

A large chemical plant in France generates both electricity and steam using a fleet of Frame 5 gas turbines. During the winter months when maximum generation capacity is utilized, excess steam may be produced. Instead of venting to atmosphere, the excess steam will now be injected into two gas turbines through a steam injection system. Power increases of up to 29.6% were achieved during testing with a corresponding increase in cogeneration fuel conversion efficiency of up to 4.8%.

This paper describes the preliminary engineering, design, fabrication, installation, test and operation of the steam injection system for the two Frame 5 gas turbines.
An Indirectly Fired Gas Turbine Cogeneration Plant Utilizing Sawdust as a Fuel
Authors: Evans R. L. , Sinclair M. S. , Constable G. A. , Halewood T.
Published: March 2015

A technical and economic assessment of an indirectly fired gas turbine cogeneration system is presented. The plant is designed for use in a sawmill, burning sawdust to generate both electricity and process heat to dry the lumber. After being dried, the sawdust is burned in a specially designed combustor which incorporates both radiant and convective heat transfer sections to generate a supply of air heated to 760 C (1400). This hot air drives the gas turbine and then the exhaust stream is utilized as a heat source for drying lumber in the dry-kilns. A materials and energy balance is presented which shows that there is more than enough sawdust available in a typical sawmill to supply all of the process heat requirements and to generate most of the electricity required to operate the mill machinery. This site-specific feasibility study indicates that an indirectly-fired gas turbine cogeneration system should be both technically and economically viable for application in a sawmill producing dried softwood lumber.
Flow in Single and Twin Entry Radial Turbine Volutes
Authors: Lymberopoulos N. , Baines N. C. , Watson N.
Published: March 2015

This paper presents a numerical analysis and experimental measurements of flows in the vaneless volute of a radial–inflow turbine. Cases of single and twin entry to the volute were studied, and in particular the case of unequal flows, or partial admission, to the two entries. The distance between the rotor tip and the limit of the internal wall separating the two flows was varied in order to study the effects of interaction of the two streams.

The computational model is based on a quasi–three–dimensional solution of the Euler equations, in which the radial and tangential components of velocity are fully solved, but the axial component is only treated to simulate the mixing of the two streams. The results of the model were compared with published results for a single entry, and extensive new results for a single or twin entry, casing. Even in the single and equal flow twin–entry cases, significant variations in flow properties around the exit circumference of the volutes were observed, most particularly in the region of re–entry near the tongue. For unequal flows the interaction of the two streams was strong and increased with increasing separating wall diameter, and with increasing inequality of flow rates. In extreme cases the flow reverses.
The Effects of an Excited Impinging Jet on the Local Heat Transfer Coefficient of Aircraft Turbine Blades
Authors: Disimile P. J. , Paule D. M.
Published: March 2015

The primary objective of this paper is to present the results of research into the effects of periodic excitation upon the local heat transfer characteristics of a turbine blade cooled by an impinging jet of air. A curved plate (used to simulate the inner leading edge of a turbine blade) was subjected to a two-dimensional jet flow field (Re = 10,000) with a superimposed periodic acoustic disturbance. When compared to the naturally disturbed flow, the excited flow field was found to reduce the local Nusselt number and cool the blade less efficiently (by as much as ten percent in the extreme cases). The results of the study appear to indicate that harmonic disturbances present a serious controlling factor in the quest for optimization of turbine blade cooling techniques. By isolating dominant frequencies in gas turbine engines and working to suppress them, the authors believe it possible to make significant contributions towards the desired increase in turbine inlet temperature.
Off-Design Performance Prediction for Radial-Flow Impellers
Authors: Lee Shen C. , Chen Daying
Published: March 2015

A numerical method was developed to consider the two-dimensional flowfield between impeller blades of a given geometry. Solution of the laminar Navier-Stokes equations in geometry-oriented coordinates was obtained for stream functions and vorticities. Velocities and pressures were calculated to determine the output fluid-energy head. The circumferential components of the normal and shear stresses along the blade were evaluated to give the input mechanical-energy head. Performance predictions were obtained for different load conditions. Comparisons were made with the measured velocity vectors of the flowfield of an air-pump impeller and with the measured performance of a production water pump, good agreements were reached.
A Radial Mixing Computation Method
Authors: De Ruyck J. , Hirsch Ch.
Published: March 2015

A radial mixing calculation method is presented where both convective and turbulent mixing processes are included. The secondary flows needed for the convective mixing are derived from pitch averaged vorticity equations combined with integral methods for the 3D end-wall boundary layers, 3D profile boundary layers and 3D asymmetric wakes. The convective transport due to secondary flows is computed explicitly. The method is applied to a cascade and two single stage rotors. The three test cases show a very different secondary flow behaviour which allows the analysis of the relative importance of the different secondary flow effects. Turbulent diffusion is found to be the most important mixing mechanism, whereas convective mixing becomes significant when overall radial velocities exceed about 5% of the main velocities. The wake diffusion coefficient is found to be representative for the turbulent radial mixing and is the only empirical constant to be determined.
Coal-Fueled Gas Turbine Combustor Island Development
Authors: Roberts P. B. , LeCren R. T. , Cowell L. H. , Noble M. L. , Hasan A. M.
Published: March 2015

Solar Turbines Incorporated, a subsidiary of Caterpillar Inc., is currently developing under DOE sponsorship a coal-fueled version of its industrial Centaur Model H gas turbine for cogeneration applications. A critical sub-system component is the coal-fueled combustor island consisting of a Two-Stage Slagging Combustor (TSSC) with an integrated Particulate Rejection Impact Separator (PRIS). Earlier development of the TSSC consisted of basic feasibility demonstrations and emissions evaluations and has been reported previously together with preliminary system design and assessment data. This paper reports on the continued bench-scale development of the combustor island with the objective of developing a data base suitable for use in scaling-up the design by an order of magnitude to a rating consistent with application to the 3.8 MW Centaur Model H gas turbine. Development activities have included analytical and flow visualization modeling; sorbent injection tests for control of sulfur oxides; and baseline evaluations of a continuous slag removal system. A preliminary engine-size combustor island design is also presented.
A Compact, High Efficiency, Self-Cleaning Air Filtration System for a Vehicular Gas Turbine Engine
Authors: Murphy Joseph P. , Camplin Harry
Published: March 2015

This paper describes the design and development of a innovative filtration system for a vehicular gas turbine engine that contains a high efficiency self-cleaning element and is integrated with the propulsion system for a tenfold increase in filter service interval, a 1/3 reduction in overall pressure loss and a 40 percent reduction in package size.

The system consists of self-cleaning, rotating drum barrier filter surrounded by curved vortex tube precleaner panels and mounted directly to the engine inlet. A water tight external housing is provided to give the system the necessary deep water fording capability.

The conceptual design is described as well as the detailed design of both precleaner element and the self-cleaning barrier filter.

The full size prototype fabrication and testing is described to demonstrate operational integrity and cleanability.