bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experiments With a Low Specific Speed Partial Emission Centrifugal Compressor
Authors: Rodgers Colin 
Published: March 2015

This paper describes experiments that were conducted several years ago on a single-stage open face centrifugal partial emission compressor with a non-dimensional specific speed of D.15 (19.3 dimensional). The purpose of the experiments was to experimentally evaluate the partial emission compressor as a possible candidate for a high speed low flow natural gas fuel pump, the alternative to which was a larger heavier reciprocating compressor.
A review and re-analysis of the test data were conducted. The used updated compressor data reduction performance procedures and flow models to redefine the experimental compressor as a reference case in the low specific speed range of single-stage centrifugal compressors.
Normalized performance characteristics are presented for the experimental compressor in terms of efficiencies, diffuser recovery, and head coefficients versus diffuser relative flow parameter, or choke margin. Peak efficiency obtained at a De Laval number of 1.16, and nondimensional specific speed of 0.15, was 34.5%.
Stage performance is found to be dominated by diffuser geometry and choke margin, plus windage losses.
MS7001F Prototype Test Results
Authors: Brandt D. E. 
Published: March 2015

The MS7001F heavy–duty gas turbine has been designed utilizing advanced analytical methods and a substantial array of component tests. The integrity of the system required that the prototype unit, with its accessories, be rigorously tested under load. The factory load test was completed on May 18, 1988 after 387 hours and 134 start/stop cycles.
The MS7001F prototype gas turbine was instrumented with more than 3000 pieces of instrumentation in order to record all critical temperatures, pressures, flows, strains, displacements, and other pertinent data. The load device was a modified MS7001E compressor, which also supplied the means by which the MS7001F prototype compressor’s pressure ratio was increased to provide for surge margin determination. Inlet throttling of the MS7001F compressor allowed for full firing temperature operation, at reduced load.
The results of this factory prototype load test are reported in the paper as are observations made during post test teardown.
Advanced Turbine Technology Applications Project (ATTAP): Overview, Status, and Outlook
Authors: Haley Philip J. 
Published: March 2015

The ATTAP aims at proving the performance and life of structural ceramic components in the hot gas path of an automotive gas turbine engine. This Department of Energy (DOE)-sponsored, NASA-managed program is being addressed by a General Motors (GM) team drawing expertise from the Advanced Engineering Staff (AES) and from Allison. The program includes design, process development and fabrication, rig and engine testing, and iterative development of selected key ceramic components for the AGT-5 engine. A reference powertrain design (RPD) based on this engine predicts acceleration, driveability, and fuel economy characteristics exceeding those of both current engines and the DOE goals.
A low-apsect-ratio ceramic turbine rotor design has been successfully engine-demonstrated at 2200°F and 100% speed, including survival of impact and other hostile flow path conditions. Turbine flow path components have been designed for the 2500°F cycle, using improved monolithic ceramics targeted for Year 2 fabrication. Major development/fabrication efforts have been subcontracted at Carborundum, GTE Labs, Corning Glass, Garrett Ceramic Components, and Manville. Feasibility studies were initiated with Ceramics Process Systems and Drexel University.
Dual Pressure Ratio Compressor
Authors: Paine Charles J. 
Published: March 2015

The dual pressure ratio centrifugal compressor was conceived and developed as part of an advanced auxiliary power unit (APU) program (Ref. 1). The objective was to provide relatively low pressure bleed flow and high pressure turbine flow from a single stage centrifugal compressor.
Concept feasibility was first demonstrated by modifying and rig testing an existing centrifugal compressor. Subsequently, a second compressor (reference compressor), meeting the overall APU power section and bleed cycle pressure ratio requirements was designed and rig tested. This configuration was then scaled and tested in an APU.
Test results showed that the compressor efficiency and pressure ratio were approximately as predicted for the flow split off to the turbine (referred to as the turbine flow side). The bleed flow side vaneless diffuser experienced a strong flow separation. Mechanical problems were also encountered with the flow splitter shroud.
Although further development was indicated to correct the mechanical and aerodynamic problems encountered, the experiment provided a benchmark for the dual pressure ratio compressor concept.
Development of an Integrated BEM for Hot Fluid-Structure Interaction
Authors: Dargush G. F. , Banerjee P. K. 
Published: March 2015

A boundary element approach is developed for problems of hot fluid-structure interaction. The structure is idealized as a thermoelastic solid, and a time-domain, boundary-only integral formulation is described. Meanwhile, several approaches are discussed for the hot fluid. Integral equations are developed for both compressible and incompressible thermoviscous flow. Due to the presence of nonlinear convective terms in the governing differential equations, domain discretization is generally required. However, with the introduction of reference velocities, volume modeling often can be confined to regions near obstacles and walls.
All formulations are implemented for two-dimensional problems in GP-BEST, a general purpose boundary element computer program. An overview of this numerical implementation is provided, along with several illustrative examples. The present fluid formulations are appropriate in the low to medium Reynolds number ranges, however, some enhancements required for higher speed simulations are noted.
Injection Molding Development of Ceramic Turbine Components
Authors: Ohnsorg R. W. , Eyck M. O. Ten , Friedman W. D. , Engler P. , Havrilla G. J. , Armstrong E. E. 
Published: March 2015

Ceramic fabrication development of large static components has been an integral part of the U.S. Government sponsored gas turbine development programs. Carborundum has produced sintered alpha silicon carbide transition ducts which have been successfully tested in Garrett’s AGT 101 engine having a turbine inlet temperature of 2500°F. Injection molding as opposed to isopressing/green machining was chosen for the development project because of its near net shape capability and high volume potential.
Mold design is important to minimize internal flaws and provide uniform green density. Injection molding control variables also influence external surface quality as determined by knit lines and blisters. Statistically designed three level experiments were instrumental in isolating the control variables which influence part quality and to determine their optimum values. Flow modeling was used to verify field trials and optimize specific molding variables to minimize pressure, shear rate and shear stress gradients within the part as well as suggest gating options.
Destructive and nondestructive evaluation was then used to evaluate the quality of ducts at various processing steps. Dual energy tomography and X-ray fluorescence are being developed as techniques for measuring the density and composition of molded parts.
Small Cogeneration in Industry: Requirements and Solutions With an Efficient Gas Turbine
Authors: Benvenuti Erio , Stecco Sergio S. 
Published: March 2015

This paper examines some of the major problems connected with cogeneration in some typical industrial sectors. A prior study of the impact of monitorized energy consumption on the choice of cogeneration solution showed that:
- In the 0.5–3.0 MW range: Gas turbines with heat recovery represent an appealing solution in terms of overall plant costs.
- In the 0.5–0.8 MW range: Industry characteristics must be better clarified before dealing with competition from internal combustion (IC) reciprocating engines.
This study served to establish the design guidelines for the NuovoPignone PGT2 gas turbine, rated at 2 MW, with a 25% efficiency at the generator terminals. The design exhaust temperature of 550°C is well suited to cogeneration applications in the types of industry investigated (textile-, cement-, and paper-making). However, in other cases such as nonindustrial cogeneration, where very low electricity costs are desirable, the available regenerative cycle option has a potential electrical efficiency of over 28% at lower exhaust temperatures and heat levels.
The Effect of Density Ratio on the Heat Transfer Coefficient From a Film Cooled Flat Plate
Authors: Ammari H. D. , Hay N. , Lampard D. 
Published: March 2015

The effect of density ratio of cooling films on the heat transfer coefficient on a flat plate is investigated using a heat-mass transfer analogy. The experimental technique employed uses a swollen polymer surface and laser holographic interferometry. A density ratio of 1.0 was achieved using air as the injectant. Density ratios of 1.38 and 1.52, representative of turbine operating conditions, were obtained by using foreign gases.
The coolant fluids were injected at various blowing rates through a single normal hole or through a row of holes spaced at three-diameter intervals, and inclined at 35° or 90° to the mainstream direction. The experiments were conducted under isothermal conditions in a subsonic, zero mainstream pressure gradient turbulent boundary layer. The results indicated large differences in behaviour between the two injection angles. For normal injection, the heat transfer coefficient at a fixed blowing parameter was insensitive to the variation of density ratio, whereas for 35° injection strong dependence was observed. Scaling parameters for the heat transfer data have been proposed so that use can be made of data obtained at density ratios not representative of gas turbine practice. In addition, a correlation for normal injection data has been formulated.
Application of a Low Reynolds Number k-ϵ Turbulence Model to High-Speed Rotating Cavity Flows
Authors: Morse A. P. 
Published: March 2015

A low turbulence Reynolds number k-ϵ model has been used in conjunction with an elliptic flow calculation procedure to obtain finite-difference solutions for radial outflow in the cavity formed between two plane corotating discs and an outer peripheral shroud. Air enters the cavity axially through a central hole in one of the discs and is assumed to leave via a uniform sink layer adjacent to the shroud.
The main emphasis of the paper is the extension of the solution procedure to cover high rotational speeds, with rotational Reynolds numbers up to 107. As a necessary prerequisite to this exercise, the turbulence model is validated by its good predictive accuracy of existing experimental data up to a maximum rotational Reynolds number of 1.1 × 106.
Aerodynamics of Cooling Jets Introduced in the Secondary Flow of a Low Speed Turbine Cascade
Authors: Bario F. , Leboeuf F. , Onvani A. , Seddini A. 
Published: March 2015

The aerodynamic behaviour of cold discrete jets in a cold secondary flow is investigated. Configurations including single jets and rows of jets are studied.
These jets are introduced through the side wall of a low speed nozzle turbine cascade. The experimental set up and the jet behaviour are fully described.
The effects of location with respect to the blades, mass flow ratio, yaw and incidence angles on the aerodynamics of single jets are investigated. The influence of neighbouring jets is detailed in the case of multiple jet configurations. The interaction with the secondary flow is presented. The local pressure and velocity fields, trajectories and visualizations are discussed. The measuring apparatus includes a five hole probe and an hot wire for intermittency measurements.
Experimental Investigation Into the Effects of Rotating and Static Bolts on Both Windage Heating and Local Heat Transfer Coefficients in a Rotor/Stator Cavity
Authors: Millward J. A. , Robinson P. H. 
Published: March 2015

Experiments have been carried out over fully representative ranges of Rotational Reynolds Number ρωr2μ and Throughflow Reynolds Number m.μr into the effects of single row and multi rows of bolts on both windage and local disc surface heat transfer coefficients. Experiments were carried out on the following combinations; single row rotating, single row static, double row rotating and combined rotating and static. Different sizes of bolts were tested as was variation in pitching and the effects of various bolt shields.
The Adiabatic Wall Temperature (AWT) was measured locally at various positions on the rotor surface both between adjacent bolts and at different pitch circle diameters. Using measured AWT and local rotor surface temperatures the local Nusselt numbers were obtained. In addition an effective Nusselt number for heat transfer into the disc through an actual bolt was obtained by the use of specially instrumented bolts.
In the course of the testing, surprising results were obtained for one particular disc profile. A considerable reduction in windage due to the shape of the disc surface near the rim was measured.
The paper describes the experimental technique used and presents a selection of the windage and heat transfer results.
Simulation of Cooling Film Density Ratios in a Mass Transfer Technique
Authors: Ammari H. D. , Hay N. , Lampard D. 
Published: March 2015

A systematic investigation of the influence of molecular Schmidt number on cooling film mass transfer coefficient has been conducted using a swollen polymer technique and laser holographic interferometry. A variation in Schmidt number by about 28% was accomplished by injection of a foreign gas and gas mixtures through a single normal hole at a blowing rate of one. The experiments were performed at a constant temperature in a subsonic, zero mainstream pressure gradient turbulent boundary layer on a flat plate.
The experimental results indicate that Schmidt number has a negligible effect on cooling film mass transfer coefficient within the range examined. Consequently, measurement of cooling film mass transfer coefficients at non-unity density ratios using a mass transfer method with foreign gas injection is experimentally validated.
Advanced Core Technology: Key to Subsonic Propulsion Benefits
Authors: Glassman Arthur J. , Snyder Christopher A. , Knip Gerald 
Published: March 2015

A study was conducted to identify the potential performance benefits and key technology drivers associated with advanced cores for subsonic high-bypass turbofan engines. Investigated first were the individual sensitivities of varying compressor efficiency, pressure ratio and bleed (for turbine cooling); combustor pressure recovery; and turbine efficiency and inlet temperature on thermal efficiency and core specific power output. Then, engine cycle and mission performance benefits were determined for systems incorporating all potentially achievable technology advancements.
The individual thermodynamic sensitivities are shown over a range of turbine temperatures (at cruise) from 2900 to 3500 °R and for both constant (current technology) and optimum (maximum thermal efficiency) overall pressure ratios. It is seen that no single parameter by itself will provide a large increase in core thermal efficiency, which is the thermodynamic parameter of most concern for transport propulsion. However, when all potentially achievable advancements are considered, there occurs a synergism that produces significant cycle and mission performance benefits. The nature of these benefits are presented and the technology challenges associated with achieving them are discussed.
Mechanical and Process Design of the Flevo Power Station Conversion Project
Authors: Feenstra J. , Kamminga P. 
Published: March 2015

EPON operates a number of power stations in the north of the Netherlands. At some of these the forced-draught-fans have been replaced by gas turbines. Unit 3 of Flevo Power Station was the latest repowering project in the Netherlands.
This paper gives a description of the most important points of the mechanical, and process design of the combined cycle unit and the influence of the gas turbine on the starting procedure.
A Basic Analysis of Cogeneration Economics
Authors: Collet P. J. 
Published: March 2015

The economics of small scale gas turbine based cogeneration systems are analyzed on the basis of avoided costs for an electric utility exploiting such systems. This concerns a theoretical study in which the cogeneration system as a means for electricity generation is assumed to supplant the building of new central electricity generating plant.
The results show that with increasing oil and gas price levels, the economics of cogeneration will become more favourable when the supplanted capacity is for peak load rather than for base load electricity generation. This implies a preference for applications with cogeneration operation taking place mainly during on-peak hours of the electricity demand.
Effects of Adverse Pressure Gradients on the Nature and Length of Boundary Layer Transition
Authors: Walker G. J. , Gostelow J. P. 
Published: March 2015

Existing transition models are surveyed and deficiencies in previous predictions, which seriously overestimate transition length under an adverse pressure gradient, are discussed. A new model for transition in an adverse pressure gradient situation is proposed and experimental results are provided which confirm its validity. A correlation for transition length is advanced which incorporates both Reynolds number and pressure gradient effects.
Under low free-stream turbulence conditions the basic mechanism of transition is laminar instability. There are, however, physical differences between zero and adverse pressure gradients. In the former case transition occurs randomly, due to the breakdown of laminar instability waves in sets. For an adverse pressure gradient the Tollmien-Schlichting waves appear more regularly with a well-defined spectral peak. As the adverse pressure gradient is increased from zero to the separation value the flow evolves continuously from random to periodic behavior and the dimensionless transition length progressively decreases.
An Euler Solution for Unsteady Flows Around Oscillating Blades
Authors: He L. 
Published: March 2015

A time-marching Euler calculation for 2-D and quasi 3-D unsteady flows in oscillating blade rows is presented, based on a finite volume scheme with cell-vertex discretization in space and 2-step Runge-Kutta integration in time.
Extra fluxes due to the deformation of the moving finite volumes are directly included in the conservation equations in the physical coordinate system. A zonal moving grid technique is used, in which only sub-regions near oscillating blades are moved to fit both the moving (blade) boundaries and fixed regions.
For phase-shifted periodic conditions, the conventional ‘Direct Store’ method is used as a basis for comparison. Two alternative methods to save computer storage are proposed and preliminary demonstrations of their usefulness are given in the present calculations.
Calculated results for unsteady flows in an oscillating flat plate cascade are in good agreement with those from two well-established linear methods, LINSUB and FINEL. The unsteady pressure distribution and aerodynamic damping calculated by the present method for a turbine blade test case (Aeroelasticity Workshop Standard Configuration No.4 cascade) agree well with the corresponding experimental data. Computations for an oscillating biconvex cascade in transonic flow conditions are performed, which show some strong nonlinear behavior of shock wave movement.
A Variable-Geometry Power Turbine for Marine Gas Turbines
Authors: Karstensen Karl W. , Wiggins Jesse O. 
Published: March 2015

Gas turbines have been accepted in naval surface ship applications, and considerable effort has been made to improve their fuel consumption, particularly at part-load operation. This is an important parameter for shipboard engines because both propulsion and electrical-generator engines spend most of their lives operating at off-design power. An effective way to improve part-load efficiency of recuperated gas turbines is by using a variable power turbine nozzle.
This paper discusses the successful use of variable power turbine nozzles in several applications in a family of engines developed for vehicular, industrial, and marine use. These engines incorporate a variable power turbine nozzle and primary surface recuperator to yield specific fuel consumption that rivals that of medium speed diesels. The paper concentrates on the experience with the variable nozzle, tracing its derivation from an existing fixed vane nozzle and its use across a wide range of engine sizes and applications. Emphasis is placed on its potential in marine propulsion and auxiliary gas turbines.
Computation of the Flow Field and Heat Transfer in a Rectangular Passage With a Turbulator
Authors: Becker Bryan R. , Rivir Richard B. 
Published: March 2015

A detailed numerical study of the aerothermal mechanics within a short straight section of a turbine blade internal cooling passage with a single turbulator is described. The two dimensional, transient, Reynolds averaged Navier Stokes, continuity and energy equations are iterated to a steady state solution using the MacCormack explicit predictor-corrector algorithm. Turbulence closure is achieved through the use of the Baldwin-Lomax algebraic two layer eddy viscosity model.
Axial distributions of local skin friction coefficient, local Stanton number and local Nusselt number are given. Profiles of velocity and temperature are presented as well as contours of streamfunction and temperature which display complex details of the flow structure. It was found that the widely used Reynolds Analogy greatly underpredicts the heat transfer rate as given by a direct calculation using Fourier’s law. Finally, the numerical results are found to compare favorably to the experimental results published by Han et al (1986).
Through Flow Theory for Nonaxisymmetric Turbomachinery Flow: Part II — Assessment
Authors: Dring Robert P. , Oates Gordon C. 
Published: March 2015

Through flow theory has been limited in its applicability and in its accuracy by the fact that it has not historically been cast in a form which can account for the nonaxisymmetries that naturally arise in turbomachinery flow due to the presence of finite numbers of rotor and stator airfoils. The attempt to circumvent this limitation by the introduction of an aerodynamic blockage factor has been demonstrated in earlier work to produce fundamental inconsistencies in the calculation which lead to significant errors in the regions of the flow where the nonaxisymmetries are severe. The formulation in Part I of the present work is a derivation of a system of through flow equations for nonaxisymmetric flow.
A benchmark data base is used in Part II to provide input to the calculation and to help identify the dominant terms. It is demonstrated that the dominant effect of nonaxisymmetry is contained in two terms that relate the total pressure of the averaged flow to the mass averaged total pressure. It is also demonstrated that the present formulation produces a result which is more accurate than that obtained with the historical blockage-based formulation.