bluuebunny/crossref_metadata_2025 huggingface dataset:
The Reheat Power Turbine With Steam Cooling: A Means of Increasing Reheat Temperature, Exhaust Temperature and Combined-Cycle Efficiency
Authors: Rice I. G.
Published: April 2015

The reheat-gas-turbine maximum-reheat turbine-inlet temperature (RHTIT) is presently limited to about 2200°F (1204°C) due to an arbitrary exhaust temperature ceiling set at 1300°F (704°C). Last-stage power-turbine blading, support struts, casings and exhaust-hood construction and materials has imposed this restraint. This paper outlines a way to steam-cool these large parts. It presents an analysis of the combined cycle where the efficiency improvement is 2.4 percent and the output gain is 9.9 percent with a 200°F (111°C) higher RHTIT and a corresponding extended exhaust temperature and where the overall combined cycle efficiency approaches 60 percent (LHV).
An Inviscid-Viscous Interaction Treatment to Predict the Blade-to-Blade Performance of Axial Compressors With Leading Edge Normal Shock Waves
Authors: Calvert W. J.
Published: April 2015

An inviscid-viscous interaction treatment has been developed to predict the blade-to-blade flow in axial compressors operating with supersonic inlet conditions and a normal shock wave at inlet to the blade passage. The treatment uses both direct and inverse modes of operation for the inviscid and viscous calculations, and thus it can model the separation of the suction surface boundary layer produced by the strong interaction with the shock wave. The inviscid flow is calculated by a time marching method and the viscous flow by integral methods for laminar and turbulent boundary layers.
Particulate and Sulfur Oxides Emissions From a 60-MW Heavy Duty Gas Turbine Burning No. 2 Distillate Fuel: Methods Development and Test Results
Authors: Touchton G. L. , Hilt M. B.
Published: April 2015

A method for the measurement of particulate and sulfur oxides emissions has been developed and tested in the laboratory and the field. The development shows that changes in analysis methods, procedures, and materials are necessary in order to adapt standard USEPA methods to gas turbine conditions. In particular, extreme care must be taken to prevent the formation of pseudo particulate from sulfur dioxide. The field results demonstrate that a G.E. MS7001B emits less than 10 lbm/hr of total particulate if the fuel ash and sulfur content are suitably restricted.
Application of High Bypass Turbofan Computer Simulation to Flight and Test Data Processing
Authors: Chapier J. F. , Levine L.
Published: April 2015

This paper describes the computer program used to compare gas turbine engine flight and static test results with a predicted standard engine computer simulation model. The program is conceived not only for a final presentation of engine performance, but also as a research tool to further analyze the validity of measurements and the assumptions used in data reduction.
Fuel Profitability and the Design of Gas Turbine Cogeneration Plant
Authors: Ondryas I. S.
Published: April 2015

This paper describes the engineering effort involved in the selection of the topping cogeneration cycle for an industrial cogeneration plant. Fuel profitability of a cogeneration plant is defined and analyzed, and used as a tool for the selection of the cogeneration cycle. The conceptual design of a gas turbine cogeneration plant is described, which includes selection of a gas turbine generator and other major plant components, equipment sizing and the typical control system layout. The paper provides tools to the industrial plant manager/engineer for the selection of the most profitable alternative of the cogeneration system.
Effect of Turbulence on the Heat Transfer in a Laminar and Turbulent Boundary Layer Over a Gas Turbine Blade
Authors: Krishnamoorthy V.
Published: April 2015

This paper describes the results of the systematic investigations undertaken to identify the effect of free stream turbulence intensity on the local heat transfer coefficient distribution in the laminar and turbulent boundary layer present over a turbine blade profile in a two-dimensional cascade. The local heat-transfer coefficient was measured under constant heat flux boundary condition. Experiments were conducted at exit Reynolds numbers (based on blade chord) Rc = 2, 4.5 × 105 and at turbulence intensities εi up to 21.3 percent. A novel type of turbulence generator was used, with which it was possible to vary the turbulence intensity in the plane of the cascade without changing the distance between the turbulence generator and the cascade and without significantly varying the integral length scale of the turbulence.
A Practical Approach to the Design of Multivariable Control Strategies for Gas Turbines
Authors: Foss A. M.
Published: April 2015

The requirement for gas turbine engines to operate over wider ranges has resulted in today’s more sophisticated engines with multiple controls. Current control philosophy for such powerplants is to adopt separate control systems for each of the major components with the minimum of communication between them. Interactions between the various control parameters can, however, seriously degrade the performance, and a design strategy aimed to take account of these interactions — the multivariable approach — may be better. Although several multivariable design methods have been proposed, most are highly theoretical and a need exists for a more practical straightforward procedure. This paper aims to demonstrate such a procedure, based on the characteristic locus technique, for the design of a gas turbine multivariable controller.
Semi-Empirical Analysis of Liquid Fuel Distribution Downstream of a Plain Orifice Injector Under Cross-Stream Air Flow
Authors: Ming-hua Cao , Hong-kun Jiang , Ju-shan Chin
Published: April 2015

An improved semi-empirical analysis is presented for the liquid fuel distribution downstream of a plain orifice fuel injector under cross-stream airflow of uniform high velocity and constant ambient temperature. The analysis is based on a simplified “flat-fan spray” model (ε – ψ model). The ε – ψ model is proposed which assumes that the fuel injected through the orifice forms a flat-fan liquid sheet with an average fan angle 2 ψ0. Once the droplets have been formed, the trajectory of individual droplets determines the fuel distribution downstream. The validity of the analysis is confirmed by comparison of calculations based on the ε – ψ model and test data obtained from fuel distribution experiments under cross-stream air flow of ambient temperature. The agreement is shown to be very good. The semi-empirical analysis presented offers a very useful approach in the preliminary design of the fan air flow path portion of turbo-fan after-burners.
Unsteady Three-Dimensional Turbine Aerodynamics
Authors: Joslyn H. D. , Dring R. P. , Sharma O. P.
Published: April 2015

High response aerodynamic measurements were made in a large scale, axial, flow turbine model to study the unsteadiness and three dimensionality of the flow. High response velocity vector and total pressure data were acquired. A comparison was made of the results of phase lock, averaging both raw and reduced data (voltages and velocities). The velocity vector measurements showed that there were strong radial flows present as well as significant periodic changes in the flow field due to relative rotor and vane positions. Random, periodic, and total unsteadiness levels were computed from the instantaneous and phase lock averaged velocity data. Time averaged data were compared with an inviscid two-dimensional calculation. A comparison was also made of time averaged total pressure measurements obtained from high response and low response (steady-state) probes.
NASA Research in Aircraft Propulsion
Authors: Beheim M. A.
Published: April 2015

This report presents a broad overview of the scope of research presently being supported by NASA in aircraft propulsion. Aircraft systems work is performed to identify the requirements for the propulsion system that enhance the mission capabilities of the aircraft. It is an important source of innovation and creativity that drives the direction of propulsion research. In a companion effort, component research of a generic nature is performed to provide a better basis for design and provides an evolutionary process for technological growth that increases the capabilities of all types of aircraft. They are both important.
Feasibility of Modifying Large Gas Turbines for Integration With External Heat Sources
Authors: Kuo S. C. , Horton T. L. O. , Fisher E. R. , Bigger J. E.
Published: April 2015

This paper discusses the technical feasibility of modifying existing turbomachines for integration with external heat sources for electric power generation using renewable and/or alternate energy sources. One particular example is the use of a solar central receiver with a fossil combustor for hybrid solar thermal power conversion. The retrofit- and modification-of-turbomachinery approach would be applicable to both open- and closed-cycle operation with external heat sources. Therefore the open-cycle gas turbine modifications presented here are regarded as essential to closed-cycle applications as well. Four gas turbine models were selected as representative of the more attractive existing designs and sizes for solar thermal power applications, and the results of subsequent conceptual design modifications for near-term (20 to 50 MWe plant around 1990) and far-term (20 to 100 MWe plant after 1990) systems applications using turbine inlet temperatures of 840 C (1544 F) and 1100 C (2012 F), respectively, are presented.
Comparative Performance Study of Closed Cycle Gas Turbine Utilizing Cryogenic Cold
Authors: Lee W. H.
Published: April 2015

The re-evaporation of Liquefied Natural Gas (LNG) is capable of acting as a low temperature heat sink for power cycles, thereby enhancing the thermal efficiency of the cycle. Leaving aside the detail of the appropriate heat exchanger technology, the comparative performance of improved high and low temperature closed cycle gas turbines is investigated using non-dimensionalized performance analysis. It was shown that the effect of lowering the minimum cycle temperature on the efficiency is equivalent to raising the maximum cycle temperature by a multiple amount. The specific output, however, decreases to a fraction of that achieved by the cycle with the original minimum cycle temperature. Implications are drawn for the application of the closed cycle gas turbine utilizing cryogenic cold.
Demonstration of Ceramic Hot-Section Static Components in a Radial Flow Turbine
Authors: Arnold J. P. , McGovern W. , Napier J. C. , Batakis A. P.
Published: April 2015

Ceramic hot-section turbine components allow higher temperature for up-rated power and improved fuel economy. The methodology used in arriving at a successful 200-hr engine demonstration of an all ceramic nozzle is presented along with current progress in demonstrating the remaining ceramic hot-section static components.
Fuel Tolerance of Staged Combustors
Authors: Rosfjord T. J. , Sederquist R. A. , Angello L. C.
Published: April 2015

The work described herein was conducted under an Electric Power Research Institute contract, Evaluation of Synthetic Fuel Character Effects on Rich-Lean Stationary Gas Turbine Combustion Systems. The purpose of this program was to determine the effect of synthetic fuel properties on combustor emissions, performance, and durability. Four synthetic fuels and No. 2 petroleum distillate fuel were tested in a subscale combustor over a wide range of conditions with the purpose of expanding the fuels property base and range of conditions beyond that of preceding programs. Nox emissions were very low and insensitive to combustor pressure and fuel-bound nitrogen. Rich-lean results show some indication of increased smoke and liner heating with reduced fuel hydrogen content, although not as consistent as the trends for lean combustors.
Testing and Initial Operating Experience of the MS9001E Gas Turbine
Authors: Scheper G. W. , Orsino A. J.
Published: April 2015

A new 100-MW class gas turbine designed for world-wide 50-Hz utility application has been in operation at the Kirchlengern Station of the EMR power system in West Germany since December 1980. This paper describes the initial operating experience and the results of performance and other engineering test conducted at the customer site.
Design and Development of a 12:1 Pressure Ratio Compressor for the Ruston 6-MW Gas Turbine
Authors: Carchedi F. , Wood G. R.
Published: April 2015

This paper describes the design and development of a 15-stage axial flow compressor for a −6MW industrial gas turbine. Detailed aspects of the aerodynamic design are presented together with rig test data for the complete characteristic including stage data. Predictions of spanwise flow distributions are compared with measured values for the front stages of the compressor. Variable stagger stator blading is used to control the position of the low speed surge line and the effects of the stagger changes are discussed.
Time Resolved Measurements in a Low Aspect Ratio Transonic Compressor Stage
Authors: Epstein A. H. , Thompkins W. T. , Kerrebrock J. L. , Ng W. F.
Published: April 2015

The time resolved flowfield in a low aspect ratio transonic compressor stage has been studied using a high frequency response sphere probe with a bandpass of D.C. to 20 kHz in a blowdown compressor facility. Averaged over the compressor annulus, the data agree well with those measured with standard pilot type probes on the same stage in a conventional test rig. Not all the spanwise distributions agree, however. These differences are explained as errors in the pilot probe readings due to fluctuations in the flow. The experimental data are compared to the results of a three-dimensional inviscid Euler calculation.
CFD Technology for Propulsion Installation Design-Forecast for the 80’s
Authors: Paynter G. C.
Published: April 2015

Competition for the world aerospace market will continue to be intense through this decade. The aircraft industry will use CFD in this period to gain an advantageous market position by reducing the cost and risk of achieving viable configurations and removing the test derived data base as a design constraint. Use of CFD for design implies that parametric analysis will reduce reliance on parametric testing as the basis for configuration selection. Industry will increasingly emphasize development of the technology necessary to support this. Most of the industry will follow a zonal modeling strategy and take advantage of the large vector processing computers now commercially available. Areas which will pace the development of the necessary flow analysis technology include turbulence modeling, numerical error assessment and mesh generation, and experiments for code validation.
A Design Calculation Procedure for Shock-Free or Strong Passage Shock Turbomachinery Cascades
Authors: Tong Siu Shing , Thompkins W. T.
Published: April 2015

A previously described inviscid design technique has been substantially improved to allow the generation of either shock free, weak shock or low total pressure loss supersonic rotor cascade designs. Improvements have been introduced in inflow-outflow boundary conditions, imposition of geometric constraints and in shock pressure rise specifications. Calculation examples are presented for pre-compression type rotor designs.
A Three-Dimensional Turbulent Flow Analysis Method for the Rotating Channels of a Centrifugal Turbomachine
Authors: Fraser D. A. , Howard J. H. G. , Lennox W. C.
Published: April 2015

A three-dimensional turbulent flow analysis method is described based on transformations of the equations to follow an arbitrary curved passage center-line and allowing for passage area and aspect ratio variations. The numerical method is arranged to allow either parabolic or partially parabolic solution methods in the main passage direction. The method has been tested for radial turbomachine elements and comparisons are included with measured internal passage flows in a radial impeller.
The Gas Turbine Heat Exchanger in the Fluidized Bed Combustor
Authors: Holt C. F. , Boiarski A. A. , Carlton H. E.
Published: April 2015

In a current research and development program a coal fired atmospheric fluidized bed combustor is being designed to supply the heat to a closed cycle gas turbine cogeneration system. The major technical effort is directed towards the design of the in-bed heat exchanger, which is required to operate near bed temperature. This high temperature (850 C) exposes the heat exchanger tubes to potentially severe sulfidation. The corrosion behavior depends upon the intimate details of the bed environment and may be related to the occurrence of localized areas of low oxygen partial pressure and high sulfur partial pressure. This paper describes a series of measurements of oxygen partial pressure at various locations within a fluidized bed. The bed, containing densely packed heat exchanger tubes, was operated under various conditions to observe the effect of coal mixing and devolatilization on local oxygen activity. Substantial variations of oxygen partial pressure (below 10−14 atmospheres) were observed. It was noted that these locally severe variations could be substantially modified by changes in coal mixing (as through coal port design). The experiments with varying coal size suggest that rapid devolatilization is desirable and would reduce the extent of locally corrosive environments.
Unconditionally Stable Calculation of Transonic Potential Flow Through Cascades Using an Adaptive Mesh for Shock Capture
Authors: Caspar J. R.
Published: April 2015

This paper describes an unconditionally stable procedure for calculating practical transonic potential flows through two-dimensional cascades. The full potential equation is cast in conservation form and approximated in physical space with centered control area techniques. Discrete analogs of nonphysical weak solutions are eliminated by the introduction of artificial viscosity in supersonic regions using artificial compressibility in which the density is evaluated a certain distance upstream from where it is to be applied. An explicit treatment of the density causes standard iterative procedures to diverge except on relatively coarse meshes on which shocks are poorly captured. Instead, the insight of a model problem analysis is used to treat the density partially and implicitly.
Finite Element Analysis of the Dynamics of Flexible Disk Rotor Systems
Authors: Palladino J. A. , Rossettos J. N.
Published: April 2015

The trend towards higher speeds and lighter weight rotor designs, particularly in gas turbine applications, has brought about the need to consider the flexibility of the total shaft-disk-blade system in the calculation of system frequencies and whirl modes. It has been traditional to assume that blades and disks are rigid, although recent work has been aimed at evaluating the assumption of rigid disks. These works have used Laplace transform and Liapunov methods and have been limited to simple geometries. This paper describes the development of a special shaft finite element which incorporates analytical solutions for disk dynamics and approximations of blade effects. It is shown that the addition of disk and blade dynamics does not increase the size of system matrix and that this approach can consider multiple disks. Because of the versatility of the finite element approach, complex configurations and boundary conditions can be considered.
The Constant Volume Gas Turbine Cycle According to Karavodine
Authors: Vandermeulen H.
Published: April 2015

The basic distinction between the constant volume cycle and the well known constant pressure cycle for gas turbines is the method of heat supply, which necessitates a system of combustion chamber valves to contain the fluid. The object of the proposed cycle analysis, which is mainly based on the fundamental laws of mass and energy, will consider a solution for the discrepancies between the former theory and practice of constant volume gas turbines. The overall performance characteristics which emerge from this analysis show the distinct superiority of the one-valve Karavodine cycle. Evaluation by experiment for this cycle variant shows, however, besides a refinement of the model, a marginal superiority in performance for the Brayton gas turbine at low pressure ratios. Any application could probably be justified by incorporating it in Brayton turbines to diminish starting power and to improve part load performance.
A Study of Viscous Flow in Stator and Rotor Passages
Authors: Sheoran Y. , Tabakoff W.
Published: April 2015

A numerical technique to predict the viscous flow behavior in the three-dimensional domain of rotating and stationary blade passages is presented. The analysis is based upon the numerical integration of the incompressible Navier-Stokes equations. An approach is taken to combine the three momentum equations and the continuity equation into two sets of vorticity transport-stream function equations. These equations are expressed along families of arbitrarily defined orthogonally intersecting surfaces placed within the blade passage. Unlike the stream surfaces, the arbitrary surfaces allow fluid to flow across. The numerical code employs a nonorthogonal body fitted coordinate system on each of the intersecting surfaces. The solution process involves the iterative combination of the solutions on the two families of intersecting surfaces for a complete solution. The results of flow in thin blade stationary and rotating polar ducts is presented.
Experimental Evaluation of Double Circular Arc Cascade Performances
Authors: Zhen-ya Gao , Gang Cheng , Yuan-ying Sun
Published: April 2015

This paper presents a brief introduction of the test rig and the instrumentation, the test results and the preliminary analysis of variable passage cascades, and describes the effects of Axial Velocity Density Ratio (AVDR) on the major cascade performance parameters such as the incidence angle, deviation angle, critical Mach number and pressure loss. And the paper puts forward a correction method to take those effects into account. About 40 sets of the DCA cascade test data are correlated, the systematic calculation and process are made with the maximum critical Mach number as the datum point, and the correlative curves are given for design and analysis. The application of the correction method is described and the comparison is made between this method and the classical NASA method.
Penetration and Break-Up Studies of Discrete Liquid Jets in Cross Flowing Airstreams
Authors: Hussein G. A. , Jasuja A. K. , Fletcher R. S.
Published: April 2015

Penetration and breakup characteristics of a discrete liquid jet injected into a high-velocity cross flowing airstream were investigated as a basis of plain-jet airblast atomizer design. The main variables covered in this phase were, airstream velocity (from about 35 to 150 m/s), liquid jet velocity (from about 5 to 25 m/s) and injection orifice diameter (from about 0.5 to 2.5 mm). The tests were conducted under conditions of normal atmospheric pressure and temperature using still photography for penetration profile and a laser light scattering technique for mean dropsize determination. The experimental penetration data is shown to agree, reasonably accurately, with a relatively simple model developed in the paper. The analysis of the experimental breakup data reveals the airstream velocity as exercising the strongest influence upon Sauter Mean Diameter.
Fabrication of Turbine Components and Properties of Sintered Silicon Nitride
Authors: Neil J. T. , French K. W. , Quackenbush C. L. , Smith J. T.
Published: April 2015

This paper presents a status report on the injection molding of sinterable silicon nitride at GTE Laboratories. The effort involves fabrication of single axial turbine blades and monolithic radial turbine rotors. The injection molding process is reviewed and the fabrication of the turbine components discussed. Oxidation resistance and strength results of current injection molded sintered silicon nitride as well as dimensional checks on sintered turbine blades demonstrate that this material is a viable candidate for high temperature structural applications.
Low Heating Value Fuel Burning Capabilities of General Electric Industrial Gas Turbines
Authors: Battista R. A. , Pandalai R. P. , Hilt M. B.
Published: April 2015

The advent of higher fuel prices and operational costs associated with energy production have had a profound impact on the application of the gas turbine as a prime mover. This paper describes an extensive program carried out by the General Electric Company to demonstrate the ability of both the heavy-duty and aircraft-derivative gas turbines to operate satisfactorily while burning a wide range of lower heating value fuels, typical of industrial process or gas conditioning plants. Analytical predictions of flammability limit changes due to fuel composition variations, and combustion inlet air temperature effects are compared with small scale atmospheric burner tests. Finally, full scale single burner and sector test results are presented which demonstrate the capability of present generation combustion systems to operate on lower heating value fuels.
Performance Improvement Features of General Electric Turbofan Engines
Authors: Lennard D. J. , Fasching W. A.
Published: April 2015

Soaring fuel costs have triggered the development of a new generation of aircraft propulsion systems as well as performance modifications to current systems. This paper presents performance improvement features for General Electric turbofan engines that have either been developed or are being developed for commercial use. A number of these performance improvement features were the direct result of technology developed under the sponsorship of the National Aeronautic and Space Administration’s Engine Component Improvement (ECI) Program and the evolution of some of these performance improvement features is traced through current and future engines. Discussions will be directed toward performance features such as fan and exhaust nozzle aerodynamics improvements, improved turbomachinery clearance control, reduced flowpath losses, and high efficiency turbine cooling.
Interim Review of the Energy Efficient Engine (E3) Program
Authors: Gardner W. B. , Hannah W. , Gray D. E.
Published: April 2015

The status of the NASA sponsored Energy Efficient Engine Program, being conducted by Pratt & Whitney Aircraft, is reviewed. The current performance status is discussed; and the results of three technology programs, the shroudless fan, the segmented combustor and the mixer are reviewed. A projection is presented of the performance potential of the Energy Efficient Engine technology.
Three-Dimensional Effects in Supersonic and Transonic Compressor Rotors: An Experimental and Computational Study
Authors: Broichhausen K. D. , Gallus H. E.
Published: April 2015

A computation method for the three-dimensional rotational flow through transonic and supersonic rotors is described and discussed by means of a comparison with experimental results. The computation treats subsonic and supersonic flows with different algorithms. The compression shocks are calculated as real three-dimensional discontinuities on the basis of the Rankine-Hugoniot-equations. The experimental data result from measurements in transonic and supersonic compressor rotors. A comparison of the data shows to what extent these three-dimensional effects are covered by the described theory.
Critical Speed in Centrifugal Pumps
Authors: Gopalakrishnan S. , Fehlau R. , Lorett J.
Published: April 2015

In high pressure centrifugal pumps the magnitude of the critical speed is strongly affected by the presence of liquid in the close clearance spaces of sealing rings and throttle bushings. The stiffening and damping effect resulting from the non-axisymmetric pressure drop across such gaps is often large compared with the elastic stiffness of the shaft. In many cases it raises the critical speed far above the “dry” value, and in some cases it eliminates the critical speed altogether. As a consequence, design specifications based on shaft critical speeds, calculated disregarding the effects of the fluid, become quite meaningless. In this paper simplified equations are derived for the calculation of the effect of the fluid gap. The results have been verified by measurements on a test pump. Sample calculations for a typical multistage boiler feed pump are included as illustration.
Nonlinear Bearing Effects on Rotor Dynamic Analysis
Authors: Colsher R. , Anwar I. , Obeid V.
Published: April 2015

Nonlinear effects due to fluid film bearings become significant when vibratory amplitudes are large. To include these effects in rotor dynamic analysis requires conducting time-transient response analysis, where the fluid film forces are estimated at each time step. The present paper describes an approach where a unique treatment of bearing forces results in an efficient computational scheme for performing time transient analysis. The method developed is applicable to a flexible-rotor system with multi-degrees of freedom. A study conducted on a canned annulus motor pump using tilting pad bearings for the rotor support is described in this paper. The results showed severe loading at the bearings due to the canned annulus forces. Nonlinear effects due to the bearings were found only at large rotor unbalance loads.
Engine Dynamic Analysis With General Nonlinear Finite Element Codes: Part II — Bearing Element Implementation, Overall Numerical Characteristics and Benchmarking
Authors: Padovan J. , Adams M. , Fertis D. , Zeid I. , Lam P.
Published: April 2015

In an attempt to increase jet engine efficiences, typically smaller rotor-stator-running clearances are being employed. Because of this and the ever present need to improve maintenance, reliability and structural integrity under various modes of operation, more sophisticated analyses tools are required to model the engine. Due to the wide-spread usage of general purpose finite element codes, this report seeks to adapt the procedure to use in modeling turbine rotor-bearing-stator structure. The work outlined in this report covers the second phase of work on a three-phase NASA Lewis sponsored research grant on engine dynamic simulation by developing strategies which enable the use of available finite element codes.
Ceramic Turbine Housings
Authors: McLean A. F.
Published: April 2015

Ford’s research and development of ceramic flowpath components for uncooled, 1370°C (2500°F), vehicular turbine engines has become well known over the past decade. This paper, for the first time, describes parallel and associated developments to apply ceramics to engine inner housings. Design concepts are reviewed and compared to conventional sheet metal or cast iron structures to provide internal hot gas transition ducts. Candidate ceramic material properties are compared, leading to selection and development of lithium-aluminum-silicate. Forming processes such as slip casting and glass forming are reviewed along with problems experienced with such a relatively large ceramic component. Evaluation methods are presented and salient engine and rig testing is reviewed to establish the potential for ceramic turbine housings.
Experience Gained in Operation of the GTS Finnjet Gas Turbines and Improvements in Ship’s Fuel Economy
Authors: Pylkkänen O. , Saunamäki J.
Published: April 2015

This paper briefly describes the use of gas turbines of the GTS Finnjet, matters concerned with maintenance and repair as a result of four years’ experience (45,000 engine hours) in service, using light distillate fuel. The research and modifications required for changeover to blended residual fuel oils in gas turbines are then reviewed, as well as the first experiences (4,000 engine hours) in using the blended fuel oils during the summer of 1981. Finally we describe how the fuel economy was further improved by installing a diesel-electric machinery on the car deck to be used for manoeuvring and low season journeys.
A Procedure for Evaluating Fuel Composition Effects on Combustor Life
Authors: Foltz H. L. , Kenworthy M. J.
Published: April 2015

A generalized method is presented for estimating the effects of fuel composition on liner life. This method avoids the detail temperature and stress distribution calculations required when using conventional cyclic material property charts. The simplified approach became possible when it was found that cyclic life ratios due to fuel change were very similar when correlated with a convenient temperature parameter that had already been used in the past to correlate fuel composition with metal temperature change. This life ratio was found to be relatively independent of: (1) the peak temperature existing with the base fuel; (2) the coolant temperature; and (3) the actual detailed stress calculation. A trend of increased life ratio effect at longer cyclic lives for crack initiation was found. This trend can be incorporated into life ratio estimates from the prepared curves by using the actual observed service life without the need for a calculated absolute life.
Development of a Low Cost Performance Monitoring System for Use on Board Naval Vessels
Authors: Matthee F. A. H. , Saravanamuttoo H. I. H.
Published: April 2015

The availability of modern programmable calculators permits the development of low cost performance monitoring systems for onboard use on ships. Any system developed must be acceptable to normally qualified marine engineers, and a simple system using existing ship’s instrumentation to produce trend plots has been developed. Although extremely simple in concept, a diagnostic capability is provided; the level to which diagnosis can be carried out is dependent on the level of instrumentation provided. Tests have been carried out both on shore and at sea and the system shows great promise.
Heat Transfer Optimised Turbine Rotor Blades: An Experimental Study Using Transient Techniques
Authors: Nicholson J. H. , Forest A. E. , Oldfield M. L. G. , Schultz D. L.
Published: April 2015

Conventionally, high pressure turbine blading is optimized for aerodynamic performance without any film cooling applied to the surfaces of the blades. It is considered that modern boundary layer prediction techniques are now sufficiently accurate to allow the heat transfer to be considered at the profile design stage. Two turbine rotor profiles were designed, each with a heat-transfer-optimised pressure surface, and a detailed experimental study using transient techniques in the Oxford cascade tunnel was made. The results show that significant reductions in pressure surface heat transfer can be achieved by boundary layer optimization without compromising the aerodynamic efficiency of the blades. A description of the profiles is given, together with transfer rate measurements, pressure distribution, and aerodynamic loss measurements (a technique developed to measure aerodymanic loss in a transient cascade is described) and flow visualisation photographs.
On the Thermal Stresses Generated in Cylindrical Shells With Application to Gas Turbine Combustors
Authors: Nied H. A.
Published: April 2015

The thermal stresses generated in a cylindrical shell due to axisymmetric temperature fields, which vary in the longitudinal direction, are examined by using an influence function formulation. Closed form solutions for the longitudinal, hoop and shear stresses are derived for any axially varying temperature distribution expressible by a Fourier expansion. The thermal stresses generated in a typical cylindrical gas turbine combustor cooled by periodically spaced circumferential bands of cooling holes are investigated using the derived solutions. It is shown that a critical pitch in the cooling hole spacing can create high bending stresses at the cooling holes which could contribute to thermal fatigue failure.
A Short-Duration Blowdown Tunnel for Aerodynamic Studies on Gas Turbine Blading
Authors: Baines N. C. , Oldfield M. L. G. , Jones T. V. , Schultz D. L. , King P. I. , Daniels L. C.
Published: April 2015

A blowdown tunnel has been constructed for testing large-scale models of gas turbine blading to measure pressure distributions and losses, and for fundamental studies of boundary layers and secondary flows. It can accommodate cascades of approximately 100-mm chord, 300-mm span, and sufficient passages to achieve periodicity, or larger blades up to about 300-mm chord with fewer passages. The exit Reynolds number per metre range is 3 × 105 to 6 × 107 at unity exit Mach number, and the maximum exit Mach number is typically 1.45. These limits are well in excess of likely developments in gas turbine technology in the foreseeable future. The tunnel has a running time of 3–5 sec, which means that a small and inexpensive compressor plant is sufficient to supply the system. A pressure regulator produces a constant supply presssure regardless of line pressure fluctuations. The cascade exit pressure is controlled by tandem ejector pumps which produce sub-atmospheric conditions. The cascade Reynolds and Mach numbers may thus be independently and continuously varied.
An Advance in Reversing Transmissions for Ship Propulsion
Authors: Clements H. A. , Fortunato E.
Published: April 2015

In 1979, a paper was presented at the A.S.M.E. Gas Turbine Conference introducing a new design of reversible converter-coupling which is used in combination with a direct drive clutch to provide a compact reversing gearbox. This latest paper describes the tests and development work carried out on a full-size reversible converter-coupling, following the model testing reported earlier. This paper also describes various types of reversing gearboxes incorporating the reversible converter-coupling and compares such designs with other methods of ship manoeuvring.
Rotational Flow Calculations in Three Dimensional Blade Passages
Authors: Lacor C. , Hirsch Ch.
Published: April 2015

A method to calculate the three-dimensional, inviscid, rotational flow in blade passages is described. The three-dimensional flow is separated into a potential part and a rotational part. For a certain class of inlet flows, this rotational part can be described by a single additional function. The solution method can be seen as an extension of the procedure for solving the three-dimensional potential flow. The Finite Element technique is used and the method is illustrated by calculations of the flow in a rectangular elbow with 90 degrees of turning. Comparisons are made with experimental data and other calculation methods.
Base Pressure on a Blunt Base in Transonic Flow: Some Effects of Base Geometry and Bleed Air
Authors: Motallebi F. , Edwards S. J. , Norbury J. F.
Published: April 2015

An experimental investigation has been carried out on an aerofoil-like body having a thick square-cut trailing edge. Measurements of base pressure have been made for a range of mainstream Mach numbers from 0.6 to 1.3. The results also include measurements of vortex shedding frequency and schlieren photographs. Bleed air was discharged through the blunt base using three different configurations: (i) A wide two-dimensional slot; (ii) A narrow two-dimensional slot; (iii) A series of accurately bored discrete holes, equal in total area to the narrow slot. As the rate of discharge of bleed air was increased from zero the base pressure was found to rise to a maximum value before falling again at higher rates of discharge. At zero incidence the three configurations gave similar results but when incidence was applied the results were markedly different for the wide and narrow slots.
Experimental Investigations on the Flow in the Impeller of a Centrifugal Fan
Authors: Caignaert G. , Desmet B. , Stevenaert D.
Published: April 2015

A centrifugal research fan facility, designed for pressure measurements on the impeller blades is described in this paper. Results of mean and fluctuating pressures are presented, showing how the flow is three-dimensional and rather unsteady. An analysis of rotating stall at low flow rates is also presented.
The Influence of Flow Rate on the Wake in a Centrifugal Impeller
Authors: Johnson M. W. , Moore J.
Published: April 2015

Three-dimensional flows and their influence on the stagnation pressure losses in a centrifugal compressor impeller have been studied. All 3 mutally perpendicular components of relative velocity and stagnation pressure on 5 cross-sectional planes, between the inlet and outlet of a 1 m dia shrouded impeller running at 500 rpm were measured. Comparisons were made between results for a flow rate corresponding to nearly zero incidence angle and two other flows, with increased and reduced flow rates. These detailed measurements show how the position of separation of the shroud boundary layer moved downstream and the wake’s size decreased, as the flow rate was increased. The wake’s location, at the outlet of the impeller, was also observed to move from the suction surface at the lowest flow rate, to the shroud at higher flow rates.
Secondary Flow Effects and Mixing of the Wake Behind a Turbine Stator
Authors: Binder A. , Romey R.
Published: April 2015

In highly loaded turbines with large hub/tip ratios there is a marked increase in secondary flow effects. The optimization of the turbine flow requires detailed knowledge both of three-dimensional cascade flow and of the wake impinging on the downstream rows of airfoils. Therefore, in the DFVLR, thorough investigations of a single-stage turbine with cold air flow were performed. The stator of this turbine was designed for transonic flow and has a hub/tip ratio of 0.756 and an aspect ratio of 0.56. First, measurements were taken without the rotor in several sections behind the turbine stator with special regard to the mixing of the wakes and secondary vortices. Distributions of total pressure loss coefficient and flow direction give the order of magnitude of the mixing losses. Also, position, intensity, structure, and development of secondary vortices are shown. Some complementary measurements were carried out using five-hole probes. They confirm the above described results from two-dimensional measurements.
Kawasaki Gas Turbine Engines for Generator Sets
Authors: Otsuki Y. , Nishihara Y. , Ito E. , Hoshino A. , Inobe I.
Published: April 2015

Since 1972, Kawasaki Heavy Industries, Ltd., in Japan has been promoting development of a series of smaller size industrial gas turbine engines. Kawasaki now has eight models of their own gas turbines in production. These models, which include increased power types and twin types, consist of three base series ranging in output power from 260 PS to 4,000 PS. All of these engine models were successfully completed in a short period with the aid of the scale-up and -down design development method. They are assembled as a prime mover into a series of Kawasaki gas turbine generator sets. A bout 360 units are now in service with a large variety of customers. This paper gives a general description of these Kawasaki development industrial gas turbines with some of the features highlighted.
An Examination of the Mechanism of Flame Stabilization by the Interaction of a Rich Two-Phase Combustible Mixture Jet With a Counter Air Stream
Authors: Wierzba I.
Published: April 2015

An extensive investigation was made of the mechanism of flame stabilization by the interaction of a rich two-phase (vapor-liquid) mixture jet with a counter air stream. It was found that the ratio of the mass velocity of the main stream to that of the jet (m) is a very important parameter determining the main features of the flow and flame structures. Moreover, the similarity of the flow with respect to the mass velocity ratio in the region of the interaction between the air-fuel jet and the air stream was a significant finding. Different mechanisms of flame stabilization were recognized in the vicinity of the rich and lean limits.
Generator Design Criteria for Large Gas Turbine Power Plants
Authors: Brown J. M. , Slanker E. J. , Charron M. A.
Published: April 2015

Experience with large gas turbine power plants shows a trend of increasing operating hours, which demonstrates that for mid-range and baseload applications there is a need to consider efficiency as well as maintenance and environmental factors in the generator selection criteria. Three types of generators: open ventilated air-cooled, totally enclosed water-to-air-cooled, and totally enclosed hydrogen-cooled, are discussed, along with the classes of user operations which are defined as peaking, mid-range and baseload. Information is presented that shows the hydrogen-cooled generator (long the preferred type for steam plants) as the recommended choice for most installations operating in excess of 1500 hr per year.
The Last-Stage Test Stand as a Facility to Investigate the Phenomena in the LP-Part of Large Steam Turbines
Authors: Wachter J. , Eyb G.
Published: April 2015

Improvements of large steam turbines require results from experimental investigations on real turbines. At the Institute fur Thermische Stromungsmaschinen a new Last-Stage test stand has been built providing extended facilities for investigations of flow, steam moisture and vibration phenomona. This contribution presents a description of the test stand with its various set-up configurations for the evaluation of the data to be obtained. The measurement, data acquisition and evaluation systems are explained.
The AGT101 Advanced Automotive Gas Turbine
Authors: Rackley R. A. , Kidwell J. R.
Published: April 2015

The Garrett/Ford Advanced Gas Turbine Powertrain System Development Project, authorized under NASA Contract DEN3-167, is sponsored by and is part of the United States Department of Energy Gas Turbine Highway Vehicle System Program. Program effort is oriented at providing the United States automotive industry the technology base necessary to produce gas turbine powertrains competitive for automotive applications having: (1) reduced fuel consumption, (2) multi-fuel capability, and (3) low emissions. The AGT101 powertrain is a 74.6 kW (100 hp), regenerated single-shaft gas turbine engine operating at a maximum turbine inlet temperature of 1644 K (2500 °F), coupled to a split differential gearbox and Ford automatic overdrive production transmission. The gas turbine engine has a single-stage centrifugal compressor and a single-stage radial inflow turbine mounted on a common shaft. Maximum rotor speed is 10,472 rad/sec (100,000 rpm). All high-temperature components, including the turbine rotor, are ceramic. AGT101 powertrain development has been initiated, with testing completed on many aerothermodynamic components in dedicated test rigs and start of Mod I, Build 1 engine testing.
Combustion Turbine Deposition Observations From Residual and Simulated Residual Oil Studies
Authors: Whitlow G. A. , Lee S. Y. , Mulik P. R. , Wenglarz R. A. , Sherlock T. P. , Cohn A.
Published: April 2015

Burning residual oil in utility combustion turbines and the consequent deposition on blades and vanes may adversely affect reliability and operation. Corrosion and deposition data for combustion turbine materials have been obtained through dynamic testing in pressurized passages. The deposition produced by the 1900°F (1038°C) combustion gases from a simulated and a real residual oil on cooled Udimet 500 surfaces is described. Higher deposition rates for the doped fuel than for the real residual oil raised questions of whether true simulation with this approach can be achieved. Particles 4–8 μ m in dia predominated in the gas stream, with some fraction in the 0.1–12 μ m range. Deposition rates seemed to be influenced by thermophoretic delivery of small molten particles, tentatively identified as magnesium pyro and metavanadates and free vanadium pentoxide, which may act to bond the larger, solid particles arriving by inertial impaction to turbine surfaces. Estimated maintenance intervals for current utility turbines operating with washed and treated residual oil agreed well with field experience.
100-MW Combustion Turbines in Combined Cycles and Peaking in Ireland
Authors: Kelly A. G.
Published: April 2015

Six 100-MW combustion turbines, two of them in combined cycle, are added to the system of the Electricity Supply Board of Ireland. The combined cycle plants use existing old steam turbines and the first is operating since 1979. The reasons for the choice of this plant on a 3600-MW isolated utility are described with operating experiences to date.