bluuebunny/crossref_metadata_2025 huggingface dataset:
The Interaction Between the Axial Compressor and the Downstream Distorting Component
Authors: Tang Guo-Cai
Published: March 2015

An investigation is presented of the interaction between a compressor and a downstream distorting component, which is of increasing importance for modern aircraft turbine engines with compact size. The prediction is based on a time–marching method for compressible flow and large perturbation. The results show that the flow field of a compressor is modified by the interaction between the compressor and the downstream distorting component. Nonuniformity in the exit static pressure, maximum distortion at the last blade row implying possible critical source for instability are characteristic of the flow field with downstream distortion. A matching map is introduced to describe the whole flow process, giving clearer insight in the physical aspect to the influence of various factors on the propagation of the downstream distortion. The spacing between the compressor and the downstream distorting component is shown to have an influence of exponential type on the distortion at every axial position. The variation of the distortion with distortion coefficient is basically linear. Steeper characteristics of the compressor will produce stronger attenuation of the distortion. Compressors of multistages have an effect similar to the steeper characteristic.
An Investigation of the Dynamic Characteristic of Axial Flow Compressors
Authors: Tang Guo-Cai , Hu Bing , Zhang Hui-Ming
Published: March 2015

This paper reports an experimental investigation of the dynamic behaviour of an axial flow compressor when the flow rate is forced to vary quickly. The results are discussed in two aspects: general trends and special points. Generally, there is a deviation of the dynamic characteristic from the steady–state one, depending upon the algebraic sum of the inertial effect and the lag effect. For the present axial flow compressor, lightly–loaded, the dynamic characteristic goes above the steady–state one while closing the valve and below the steady–state one for opening the valve. Physical explanation is given to the general trend and also to the difference between the behavior of the axial flow compressor and that of the centrifugal compressor. Specially, the rapid closing of the valve will end up with an operating point end dynamic breaking into the instability limit while the throttle setting is somewhat away from the instability limit position for steady–state operation; and the rapid opening of the valve may produce an initial transient decrease in flow rate thus may have an initial dynamic breaking into the instability limit. Physical explanation is also given to these two special points, which are of great engineering interest with regard to the instability issue.
Aerothermal Boundary Layer Computation Including Strong Viscous-Inviscid Flow Interaction
Authors: Kulisa P. , Leboeuf F. , Klinger P. , Bernard J.
Published: March 2015

The high temperature level reached at the exit of combustion chambers of modern aircraft engines and the practical limitations of advanced materials, demand efficient cooling of turbine blades. Optimization of the cooling requires an accurate prediction of aerodynamic losses and heat transfer on turbine blades.

A new two-dimensional compressible, aerothermal boundary layer code has been developed. The formulation includes strong viscous-inviscid interaction, which enhances the stability properties of the code. The boundary layer equations associated with the energy equation are solved with an implicit Keller-box scheme. Viscous-inviscid flow coupling is performed by adding an interaction equation which has an elliptic character. The complete system of equations is solved by a multi-pass procedure. This technique contributes to the stabilization of the method and allows the computation of regions with strong adverse pressure gradients, separation bubbles and injections in case of film cooling.

Comparisons between experimental and theoretical results are provided. Flow characteristics including heat transfer were computed for several cases such as flat plates with strong pressure gradients, and turbine blade boundary layers. Good agreement between computation and experiment is observed, demonstrating the high accuracy and robustness of the code.
Prediction of the Aerodynamic and Thermal Environment in Turbines
Authors: Griffin Lisa W. , Belford Kelly A.
Published: March 2015

A numerical study of the steady, viscous flow prediction capabilities of the three-dimensional turbine stage code R0T0R3 is presented. Computations were performed with RAI3DC, a cascade version of R0T0R3 capable of being run in a planar or annular mode. Computed results are compared with experimental data obtained for Hodson’s cascade, Kopper’s cascade, and United Technologies Research Center’s Large Scale Rotating Rig (LSRR) first-stage stator. The code’s predictive capability is assessed in terms of the accuracy of predicted airfoil loadings, performance (including secondary flows in the LSRR case), boundary layers, and heat transfer. A grid refinement study was conducted in the LSRR case in an effort to more accurately model the boundary layers on the airfoil and endwall surfaces. The effects of the inlet total pressure profile in secondary flow prediction were also assessed.
The Effect of Backswept Blading on the Flow in a Centrifugal Compressor Impeller
Authors: Farge Talib Z. , Johnson Mark W.
Published: March 2015

A comparison is made between the flow in two impellers, one with radially ending blades and one with blades backswept by 30°. The two impellers have identical inducers. Measurements are made of the three velocity components and total pressures across five measurement stations within each impeller. The flow in the backswept impeller is dominated by a counter-clockwise vortex which reduces the severity of the shroud boundary layer separation and hence leads to a higher impeller efficiency. The wake is consequently smaller in the backswept impeller but adopts a similar position on the shroud surface at the impeller exit. Analysis of the secondary flow generation reveals the mechanisms responsible for the differences in the flow fields in the two impellers.
Unsteady Velocity- and Turbulence Measurements With a Fast Response Pressure Probe
Authors: Ruck G. , Stetter H.
Published: March 2015

To investigate the three-dimensional unsteady flow and the turbulence intensities behind rotating blade rows of turbomachines, a procedure using a fast-response pressure probe has been developed. The integration of the cylindrical miniature pressure transducers into the probe head minimizes the risk of mechanical damage. The dynamic behaviour of the probe was analyzed. The application of the probe to the rotor exit flow of an axial compressor is described and results are presented.
Flow Investigation in a Small High Speed Impeller Passage Using Laser Anemometry
Authors: Ahmed N. A. , Elder R. L.
Published: March 2015

The paper describes experimental results obtained using laser velocimetry in a small high speed centrifugal impeller. The formation of wakes and the effect of varying speed and mass flow rate on the flow within the impeller passages are presented. In addition, an indication of the three dimensional nature of the impeller flow is discussed (the three dimensional results being obtained using a novel Doppler anemometer).
Semi-Inverse Design of Compressor Cascades, Including Supersonic Inflow
Authors: Kirschner A. , Stoff H.
Published: March 2015

A cascade design-method is presented which complements the meridional through-flow design procedure of turbomachines. Starting from an axisymmetric flow field and the streamline geometry in the meridional plane this simple method produces a solution for the quasi three-dimensional flow field and the blade-element geometry on corresponding stream surfaces. In addition, it provides intra-blade data on loss and turning required for a consistent design and a convenient means of optimizing blade loading. The purpose of this paper is to describe the theoretical basis of the method and to illustrate its application in the design of transonic compressors.
Gas Turbine Engine Test Cell Modeling
Authors: Salinas D. , Cooper E. E.
Published: March 2015

A numerical simulation of the aerothermal characteristics of a gas turbine engine test cell is presented. The three-dimensional system is modeled using the PHOENICS computational fluid dynamics code. Results predict the velocity field, temperatures, pressures, kinetic energy of turbulence, and dissipation rates of turbulent kinetic energy. Numerical results from two versions, a cartesian coordinate model and a body fitted coordinate model, are compared to experimental data. The comparison shows good quantitative and very good qualitative agreement, suggesting that numerical modeling would be useful in the preliminary design of gas turbine test facilities.
Influence of Periodically Unsteady Wake Flow on the Flow Separation in Blade Channels
Authors: Dibelius G. H. , Ahlers E.
Published: March 2015

The influence of periodically unsteady perturbations on the turbulent flow along the suction side of turbine blades is investigated in a test rig. The blade suction side is represented by a flat plate of 550 mm length. The pressure profile typically encountered in a turbine blade channel is generated by a curved wall opposite to the flat plate. The angle of the divergent part of the test channel and hence the pressure can be increased to induce flow separation on the flat plate. For simulation of the wakes from the upstream blade row the incoming flow is periodically disturbed by a wake generator consisting of five flat profiles arranged in front and parallel to the plate rotating with adjustable speed and phase angle.

A LDV with high spatial resolution is used to measure averaged and fluctuating components of the velocity inside the boundary layer flow down to a distance of y = 0,05 mm from the plate surface determining the boundary layer parameters as well as the wall shear stress. By Fourier analysis of the measured time related velocity distributions the stochastic and periodic parts of the overall turbulence are identified.

With a periodic wake flow the separation is shifted downstream as compared to the steady flow situation. This is due to the energization of the boundary layer flow associated with the conversion of periodic in stochastic parts of the turbulence. Conclusions resulting from the experimental findings for the theoretical understanding of the flow in turbine cascades are discussed in particular with respect to turbulence modelling.
An Experimental Investigation of Nozzle-Exit Boundary Layers of Highly Heated Free Jets
Authors: Lepicovsky J.
Published: March 2015

An experimental investigation of the effects of nozzle operating conditions on the development of nozzle-exit boundary layers of highly heated air free jets is reported in this paper. The total pressure measurements in the nozzle-exit boundary layer were obtained at a range of jet Mach numbers from 0.1 to 0.97 and jet total temperatures up to 900 K. The analysis of results shows that the nozzle-exit laminar boundary-layer development depends only on the nozzle-exit Reynolds number. For the nozzle-exit turbulent boundary layer, however, it appears that the effects of the jet total temperature on the boundary-layer integral characteristics are independent from the effect of the nozzle-exit Reynolds number. This surprizing finding has not yet been reported. Further, laminar boundary-layer profiles were compared with the Pohlhausen solution for a flat-wall converging channel and an acceptable agreement was found only for low Reynolds numbers. For turbulent boundary layers, the dependence of the shape factor on relative Mach numbers at a distance of one momentum thickness from the nozzle wall resembles Spence’s prediction. Finally, the calculated total pressure loss coefficient was found to depend on the nozzle-exit Reynolds number for the laminar nozzle-exit boundary layer, while for the turbulent exit boundary layer this coefficient appears to be constant.
Temporally and Spatially Resolved Flow in a Two-Stage Axial Compressor: Part 1 — Experiment
Authors: Stauter R. Charles , Dring Robert P. , Carta Franklin O.
Published: March 2015

The fluid dynamics of turbomachines are extremely complex, due in part to the aerodynamic interactions between rotors and Stators. It is necessary to acquire fluid dynamic data that reflect the interactive nature of a turbomachine to correlate with the fluid dynamics predicted from modern analyses. The temporal and spatial variations in the midspan aerodynamics of the second stage of a two-stage compressor have been studied with a two-component LDV system. Spatial variations were examined by traversing the LDV probe volume through a dense matrix of both axial and circumferential positions while temporal resolution was achieved by acquiring all data as a function of the instantaneous rotor position. Hence, the data set reveals rotor and Stator wake structure and decay in both the stationary and rotating frames of reference. The data also compared very favorably with extensive pneumatic measurements previously acquired in this compressor. In Part 2 of the paper, the data are used in the assessment of a prediction of the flow in the compressor using a time-accurate, thin-layer, two-dimensional Navier-Stokes analysis.
Inviscid and Viscous Solutions for Airfoil/Cascade Flows Using a Locally Implicit Algorithm on Adaptive Meshes
Authors: Hwang C. J. , Liu J. L.
Published: March 2015

A numerical solution procedure, which includes a locally implicit finite volume scheme and an adaptive mesh generation technique, has been developed to study airfoil and cascade flows. The Euler/Navier-Stokes, continuity and energy equations, in conjunction with Baldwin-Lomax model for turbulent flow, are solved in cartesian coordinate system. To simulate physical phenomena efficiently and correctly, a mixed type of mesh, the unstructured triangular cell for the inviscid region and structured quadrilateral cell for the viscous, boundary layer and wake regions, is introduced in this work. The inviscid flows passing through a channel with circular arc bump, and the laminar flows over a flat plate with/without shock interaction are investigated to confirm the accuracy, convergence and solution-adaptibility of the numerical approach. To further prove the reliability and capability of the present solution procedure, the inviscid/viscous results for flows over the NACA 0012 airfoil, NACA 65-(12)10 compressor and one advanced transonic turbine cascade are compared to the numerical and experimental data given in related papers and reports.
An Experimental Study of the Effects of Liquid Properties on the Breakup of a Two-Dimensional Liquid Sheet
Authors: Stapper B. E. , Sowa W. A. , Samuelsen G. S.
Published: March 2015

The breakup of a liquid sheet is of fundamental interest in the atomization of liquid fuels. The present study explores the breakup of a two-dimensional liquid sheet in the presence of co-flow air with emphasis on the extent to which liquid properties affect breakup. Three liquids, selected with varying values of viscosity and surface tension, are introduced through a twin-fluid, two-dimensional nozzle. A pulsed laser imaging system is used to determine the sheet structure at breakup, the distance and time to breakup, and the character of the ligaments and droplets formed. Experiments are conducted at two liquid flow rates with five flow rates of co-flowing air. Liquid properties affect the residence time required to initiate sheet breakup, and alter the time and length scales in the breakup mechanism.
Transient Stress Response of a Turbine Blade Under Non-Linear Damping Effects
Authors: Rao J. S. , Vyas N. S.
Published: March 2015

A numerical technique to compute the stress response of a turbine blade with non-linear damping characteristics, during transient operations of the rotor has been proposed. Damping is defined as a function of vibratory mode, rotor speed and strain amplitude. The technique is illustrated by computing the stress-levels at instantaneous resonant rotor speeds for a typical step-up operation of a turbomachine.
Generalized High Speed Simulation of Gas Turbine Engines
Authors: Sugiyama Nanahisa
Published: March 2015

This paper describes a real-time or faster-than-real-time simulation of gas turbine engines, using an ultra high speed, multi-processor digital computer, designated the AD100. It is shown that the frame time is reduced significantly without any loss of fidelity of a simulation. The simulation program is aimed at a high degree of flexibility to allow changes in engine configuration. This makes it possible to simulate various types of gas turbine engines, including jet engines, gas turbines for vehicles and power plants, in real-time. Some simulation results for an intercooled-reheat type industrial gas turbine are shown.
Enhanced On-Line Machinery Condition Monitoring Through Automated Start-Up/Shutdown Vibration Data Acquisition
Authors: Harker Roger G. , Handelin Gary W.
Published: March 2015

There are many benefits available through on-line machinery condition monitoring during steady state operation. However, certain dynamic vibration data is only available during a machine’s start-up and shutdown. In the past, we have limited acquisition and reduction of this dynamic data to start-up commissioning, or while troubleshooting a specific problem. This paper explores new techniques available to automate start-up and shutdown dynamic data acquisition. It then describes an effective on-line machinery information system using these techniques.
Economic Considerations of Aircraft Turbines Manufacturing
Authors: Alonso Jacinto J.
Published: March 2015

Aircraft gas turbines manufacturing started just fifty years ago; its production experienced one of the fastest evolutions of the world manufacturing industry. The purpose of this paper is to briefly describe some of the most important factors that currently affect the economic production of aircraft turbines.

Lead time for design and development of new turbines has increased with size and complexity, which makes the start of new projects much more difficult where a close liason is necessary between design and manufacturing departments. Interaction of so many activities will require a considerable coordination effort.

Estimating production costs and labour time standards will be also key factors for economic production of aircraft turbines. The effect of production quantity will be analysed using the learning curve approach which can be applied for direct and indirect labour time, material costs and material and labour burdens.
Marine Support Concepts for Aero Derivative Turbine Engines
Authors: Curry C. E. , Keppel P. W.
Published: March 2015

Aero derivative turbine engines have been developed for both commercial and military marine applications. The “field” support for these installations has been effectively derived from aircraft support systems, and, in some cases, enjoy substantial commonality in the area of operational support. This paper describes an approach used by the Allison Gas Turbine Division of General Motors to logistically support Aero derivative marine engines.
The Rolls-Royce/Turbomeca Adour: The Optimum Trainer Engine
Authors: Ferguson Michael
Published: March 2015

The Rolls-Royce/Turbomeca Adour turbofan is the most successful engine in the highly competitive market to power modern trainer and light strike aircraft. Now in use in five different aircraft types, in every corner of the world, the Adour continues to be developed to meet future evolving requirements. Over three million hours of safe, reliable operation lie behind this development. This paper reviews the current status of the engine, and looks at the near-term future of the Adour family.
Testing at the US Navy’s Gas Turbine Systems Engineering Complex
Authors: Preisel John H.
Published: March 2015

The United States Navy has developed a facility to support full scale testing of gas turbine propulsion systems. The first site at this facility is based on the gas turbine propulsion system for the newest class of surface combatants, the USS Arleigh Burke (DDG 51). The plant consists of two LM 2500 gas turbines, combined with a newly designed reduction gear, and supported by a gas turbine generator for electrical power.

This paper describes the design of the propulsion plant, and gives special emphasis to propulsion and electrical testing. The digital control system, and multiplexed communications system is described. Preliminary component, system and full scale integration test results are presented and discussed. The paper includes lessons learned from the installation of the propulsion train and the electrical systems. Finally, a brief description of the machinery control system software maintenance process, and our initial experiences with large scale software integration testing will be given.

This paper reaffirms the value of full scale systems integration testing. It also points out the fundamental role that electronics, computers, and software play in marine gas turbine systems.
Measurement and Calculation of End Wall Heat Transfer and Aerodynamics on a Nozzle Guide Vane in Annular Cascade
Authors: Harvey N. W. , Jones T. V.
Published: March 2015

Detailed measurements of surface static pressures and heat transfer rates on the aerofoil and hub end wall of an annular nozzle guide vane (in the absence of a downstream rotor) are presented. Heat transfer rates have been measured using thin film gauges in an annular cascade in the Pyestock Isentropic Light Piston Cascade. Test Mach numbers, Reynolds numbers and cascade geometry are fully representative of engine conditions. The results of 3-D calculations of surface Mach number and 2-D calculations of aerofoil heat transfer are presented and compared with the measurements.

A new method of calculating end wall heat transfer using the axisymmetric analogue for three-dimensional boundary layers is described in detail. The method uses a 3-D Euler solver to calculate the inviscid surface streamlines along which heat transfer coefficients are calculated. The metric coefficient which describes the lateral convergence or divergence of the streamlines is used to include three-dimensional effects in the calculation. The calculated heat transfer rates compare well with the measured values. Reference is made to surface flow visualization in the interpretation of the results.
3D Flow Analysis in a Linear Cascade Using a Navier-Stokes Finite Element Code
Authors: Combes J. F. , Chabard J. P. , Metivet B.
Published: March 2015

In order to solve industrial flow problems in complex geometries, a finite element code, N3S, has been developped at Electricité de France. For an incompressible unsteady flow, the Reynolds-averaged Navier-Stokes equations, with a k-ε turbulence modelling, are split into a set of equations for transport, for diffusion and a Generalized Stokes Problem. In this paper, we briefly describe the algorithms chosen to solve each step, the k-ε treatment and the boundary conditions (wall functions).

We present also the results of a flow calculation in a linear cascade at normal and high incidence and compare them with the measurements of Yamamoto (ASME papers 86-GT-185 and 88-GT-110). The main flow features and the secondary flows (i.e., the passage and the horseshoe vortex) are qualitatively well predicted by the code but some discrepancies exist in the prediction of the losses.
Ceramic Small Gas Turbine Technology Demonstrator
Authors: Bornemisza Tibor
Published: March 2015

Requirements for increased power density, improved fuel economy, and rapid start demand higher turbine inlet temperatures and turbine wheel tip speeds, resulting in the need for materials with high strength to weight ratio at temperatures in excess of 2000°F. High performance ceramics appear to be the most promising substitutes for the current cobalt-nickel based superalloys.

The numerous advantages of ceramics are coupled with several unfavorable properties, such as the brittleness, the low reliability of the ceramic pans, and the lack of established design, manufacturing and inspection techniques. The development of reliable components requires a close cooperation between the user and the manufacturer of the high performance ceramics.

Sundstrand Power Systems has been involved with the development of ceramic gas turbine components since 1972. The current Research and Development effort involves the demonstration of ceramic turbine components operating at 2200°F turbine inlet temperature.

Silicon nitride turbine wheel and stationary components were designed and subjected to a series of tests in the Gemini small gas turbine modified for this purpose. Engine start to full speed in 2.5 seconds and continuous operation at 2300°F was demonstrated.

The successful testing of the ceramic turbine components demonstrated the feasibility of the currently available structural ceramic materials for non-flight-critical and unmanned turbine applications.
Second-Generation Low-Emission Combustors for ABB Gas Turbines: Tests Under Full-Engine Conditions
Authors: Aigner M. , Mayer A. , Schiessel P. , Strittmatter W.
Published: March 2015

An experimental rig was constructed which made it possible to research the influence of air mass flow, pressure, preheating temperature, and fuel/air ratio on the behavior of a full-scale burner. Because the investigations were carried out in the high pressure test facility at the DLR in Cologne, and not in a real gas turbine, the parameters could be varied independently of one another. Based on these systematic measurements, it is possible to predict flame stability limits and emissions for any gas turbine under any operating condition. For example, it can be shown that NOx emissions from the GT8 with ABB’s new second-generation premixing burners will not exceed 25 ppm (for 15% O2) and COwet will be less than 8 ppm at full load (16 bar, 420°C). In addition, the data measured were compared to results obtained from correlations frequently used, such as that NOx is proportional to p0.5. It was shown that this equation is too optimistic even if the flame type remains unchanged.
Nozzle Guide Vane Shock Wave Propagation and Bifurcation in a Transonic Turbine Rotor
Authors: Johnson A. B. , Oldfield M. L. G. , Rigby M. J. , Giles M. B.
Published: March 2015

A study of the propagation of a Nozzle Guide Vane (NGV) trailing edge shock wave through a transonic turbine rotor passage is presented. The work was based on experimental tests carried out in the Isentropic Light Piston Tunnel in Oxford University using a rotating bar NGV shock wave simulator, together with schlieren photography and wide band width surface pressure and heat transfer rate measurements.

The study identifies a previously unexplained interaction between the incoming wave and the rotor leading edge, which causes the nucleation of a Vortical Bubble. This bubble has been shown to enhance the thermal loading on the early pressure surface of the blade. A method of controlling this bubble and heat loading is also considered.

A previously unseen “Lambda” interaction between the shock wave and the rotor pressure surface is also identified.
Numerical Prediction of Turbine Profile Loss
Authors: Xu L. , Denton J. D.
Published: March 2015

A simple numerical method for predicting the profile loss of turbine blades in subsonic and transonic flows is presented. A time marching Euler solver is used to obtain the main flow through the blade passages, the loss due to the surface friction is calculated using an integral boundary layer method, the total mixed out loss is evaluated from the mass flow and momentum balances between the trailing edge plane and an imaginary downstream plane where the flow is uniform. The base pressure acting on the trailing edge of the blade is calculated directly from the inviscid calculation without empirical correlations. The spurious numerical loss in the Euler calculation is separated from the real loss. The rationality of the approach is justified by the agreement of the prediction with a wide range of experimental measurements.
Off-Design Performance of a Linear Cascade of Turbine Blades
Authors: Tremblay B. , Sjolander S. A. , Moustapha S. H.
Published: March 2015

A recent survey of the literature showed a clear need for additional experimental results on the off-design performance of turbines, particularly for airfoils of recent design. This study presents measurements of the low-speed two-dimensional performance of a linear cascade of turbine blades with a turning angle of 87 degrees. The incidence was varied between −25 and +25 degrees in 5 degree steps. The blade surface pressures, total pressure loss coefficients and trailing-edge deviations are presented for all values of incidence. The influence of incidence on the critical Reynolds number is also examined. Surface flow visualization is presented for different values of Reynolds number and incidence to aid in the physical interpretation of the measurements. The measured total pressure losses agree very well with the new off-design correlation introduced by Moustapha et al. (1989).
Non Invasive Measurement of Strain and Temperature by Neutron Diffraction
Authors: Holden T. M. , Root J. H. , Tennant D. C. , Kroeze D. E. , Leggett D.
Published: March 2015

Two methods have been developed to determine temperature non-invasively within engineering components by neutron diffraction. The integrated intensity of a diffraction line depends on temperature through the Debye-Waller factor. The angular position of the line, in the absence of an applied load, depends on temperature through the thermal expansion coefficient. Temperature may thus be determined by accurate relative intensity measurements with respect to a reference temperature and, alternatively, by accurate measurement of the interplanar spacings. It was also shown to be feasible to measure the strain response to an applied load at elevated temperatures. Measurements were made on Waspalloy and the Ti alloy AMS 4928. For Waspalloy, for example, the thermal expansion at zero stress gave the average temperature with a precision of ± 4 K and agreed with thermocouple measurements to within 5 K on average. The intensity data suggests that temperature can be measured with a precision of ± 10 K in a loaded component.
The Influences of Fintube Characteristics on the Manufacturing and Operation of Waste Heat Recovery Boilers (W.H.R.B.) Behind Turbines
Authors: Desmet P. A.
Published: March 2015

The technological developments in the steam boiler field, induced by changes in the use of different fins and the need to save energy, has its consequential effects on the heat transfer techniques.

As the extended surface tube is one of the important components of the steam boilers and particularly of waste heat recovery boilers (WHRB) behind turbines, we want to draw the attention to recent developments in the field of finned tubes, opening new possibilities for the optimization of construction costs of WHRB on one hand and reducing the fouling problem by a new geometry of the helically wound fins on the other hand.
A Comparative Evaluation of Advanced Combined Cycle Alternatives
Authors: Bolland Olav
Published: March 2015

This paper presents a comparison of measures to improve the efficiency of combined gas and steam turbine cycles. A typical modern dual pressure combined cycle has been chosen as a reference. Several alternative arrangements to improve the efficiency are considered. These comprise the dual pressure reheat cycle, the triple pressure cycle, the triple pressure reheat cycle, the dual pressure supercritical reheat cycle and the triple pressure supercritical reheat cycle. The effect of supplementary firing is also considered for some cases. The different alternatives are compared with respect to efficiency, required heat transfer area and stack temperature. A full exergy analysis is given to explain the performance differences for the cycle alternatives. The exergy balance shows a detailed breakdown of all system losses for the HRSG, steam turbine, condenser and piping.
A New Method of Predicting the Performance of Gas Turbine Engines
Authors: Yonghong Wang
Published: March 2015

This paper points out that the turbine performance computation method used widely at present in solving the performance of gas turbine engines is a numerically instable algorithm. So a new method, namely inverse algorithm, is proposed.

This paper then further proposes a new mathematical model of solving the stable performance of gas turbine engines. It has the features of not only being suitable for inverse algorithm for turbine performance, but also having less dimensions than existing models. So it has the advantages of high accuracy, rapid convergence, good stability, less computations, and so forth. It has been fully proven that the accuracy of the new model is much greater than that of the common model for gas turbine engines. Additionally, the time consumed for solving the new model is approximately 1 / 4 ∼ 1 / 10 of that for the common model. Therefore, it is valuable in practice.
Corrosion and Degradation of Ceramic Particulate Filters in Direct Coal-Fired Turbine Applications
Authors: Sawyer John , Vass R. J. , Brown N. R. , Brown J. J.
Published: March 2015

High temperature ceramic filters show considerable promise for efficient particulate removal from coal combustion systems. Advanced coal utilization processes such as direct coal-fired turbines require particulate free gas for successful operation. This paper describes the various ceramic particulate filters under development and reviews the degradation mechanisms expected when operated in coal combustion systems.
MS3002 Advanced Tech Upgrade Application and Operating Experience
Authors: Grondahl Clayton M. , Guiler Marvin E.
Published: March 2015

Modernization of MS3002 gas turbines produced by GE from 1951 to 1973 has been accomplished with the application of advanced technology components in a redesigned turbine hot section. Texas Eastern installed the first modernization package in 1986 and now have 10 units in service totalling more than 135,000 operating hours.

This paper presents the user’s motivation to refurbish 30 year old gas turbines, including details of the uprate installation and subsequent operating experience. Specifics of the advanced technology components in these units are provided including their impact on unit performance and reliability.
Mixing in Axial-Flow Compressors: Conclusions Drawn From 3-D Navier-Stokes Analyses and Experiments
Authors: Leylek J. H. , Wisler D. C.
Published: March 2015

Extensive numerical analyses and experiments have been conducted to understand mixing phenomena in multistage, axial-flow compressors. For the first time in the literature the following are documented: detailed 3-D Navier-Stokes solutions, with high-order turbulence modeling, are presented for flow through a compressor vane row at both design and off-design (increased) loading; comparison of these computations with detailed experimental data show excellent agreement at both loading levels; the results are then used to explain important aspects of mixing in compressors. The 3-D analyses show the development of spanwise and cross-passage flows in the stator and the change in location and extent of separated flow regions as loading increases. The numerical solutions support previous interpretations of experimental data obtained on the same blading using the ethylene tracer-gas technique and hot-wire anemometry. These results, plus new tracer-gas data, show that both secondary flow and turbulent diffusion are mechanisms responsible for both spanwise and cross-passage mixing in axial-flow compressors. The relative importance of the two mechanisms depends upon the configuration and loading levels. It appears that using the correct spanwise distributions of time-averaged inlet boundary conditions for 3-D Navier-Stokes computations enables one to explain much of the flow physics for this stator.
An Experimental Study of Local Wall Shear Stress, Surface Static Pressure and Flow Visualization Upstream, Alongside, and Downstream of a Blade Endwall Corner
Authors: Abdulla A. K. , Bhargava R. K. , Raj R.
Published: March 2015

An experimental study reported in this paper was intended to acquire information on the distribution of wall shear stress and surface static pressure in a blade endwall corner. The blade endwall corner region investigated was divided into three sections: 0.4 chord length upstream of the blade leading edge, inside the endwall corner region, and one-chord length downstream of the blade trailing edge. Maximum increase in the values of wall shear stress were found to exist on the endwall, in the corner region, between the blade leading edge and the location of maximum blade thickness (≈140% maximum increase, compared to its far upstream value, at x/D=6). Surface flow visualization defined the boundaries of the vortex system and provided information on the direction and magnitude of the wall shear stress. The acquired results indicated that the observed variations of wall shear stress and surface static pressure were significantly influenced by the interaction of secondary flows with pressure gradients induced by the presence of blade curvature.
Shop Test of the 501F a 150 MW Combustion Turbine
Authors: Entenmann D. T. , Fukue I. , North W. E. , Muyama A.
Published: March 2015

The 501F is a 150 MW-class 60 Hz engine jointly developed by Westinghouse Electric Corporation and Mitsubishi Heavy Industries, Ltd. This paper describes the full load shop test program for the prototype engine, as carried out in Takasago, Japan. The shop test included a full range of operating conditions, from startup through full load at the 1260°C (2300°F) design turbine inlet temperature. The engine was prepared with more than 1500 instrumentation points to monitor flow path characteristics, metal temperatures, displacements, pressures, cooling circuit characteristics, strains, sound pressure levels, and exhaust emissions. The results of this shop test indicate the new 501F engine design and development effort to be highly successful. The engine exceeds power and overall efficiency expectations, thus verifying the new concepts and design improvements.
Integrated Propulsion System Requirements for Control of STOVL Aircraft
Authors: Gallops G. W. , Weiss C. F. , Carlton R. A.
Published: March 2015

This paper describes an evaluation of propulsion system requirements and capability for a Short Take Off / Vertical Landing (STOVL) aircraft employing modulation of the propulsive lift distribution for pitch and roll control in hover. The effects of propulsive lift nozzle configuration and propulsion system dynamic response were evaluated using a combined system simulation consisting of a six degree of freedom aircraft model, engine model and integrated flight/propulsion control. The response and stability of propulsive lift control is compared with control by reaction jets supplied by engine bleed. Aircraft performance is demonstrated in simulated STOVL maneuvers using a dynamic pilot model. The conclusion of this study is that propulsive lift control of aircraft pitch and roll is feasible and can provide as much as a 10 percent increase in engine lift rating over systems which employ reaction control alone. The dynamic response of practical propulsive lift configurations, however, is less than that of reaction control configurations which must be offset through integration of the propulsion system and its control.
Coal-Derived Gas Utilization in Combined Gas-Steam Cycle Power Plants
Authors: Tuccillo R. , Fontana G. , Jannelli E.
Published: March 2015

In this paper, a general analysis of combined gas-steam cycles for power plants firing with both hydrocarbons and coal derived gas is reported.

The purpose of this paper is to study the influence on power plants performance of different kind of fuels and to evaluate the most significant parameters of both gas and combined cycle.

Results are presented for plant overall efficiency and net specific work, steam to gas mass flow ratio, dimensionless gas turbine specific speed and diameter, CO2 emissions etc., as functions of gas cycle pressure ratio and of the combustion temperature.

Furthermore, for an existing power plant with a 120 MW gas turbine, the authors try to establish in which measure the combined cycle characteristic parameters, the gas turbine operating conditions, and the heat recovery steam generator efficiency, are modified by using synthetic fuels of different composition and calorific value.

The influence is also analyzed either of bottoming steam cycle saturation pressure or — in a dual pressure steam cycle — of dimensionless fraction of steam mass flow in high pressure stream.

The acquired results seem to constitute useful information on the criteria for the optimal design of a new integrated coal gasification combined cycle (IGCC) power plant.
Combined Cycles Permit the Most Environmentally Benign Conversion of Fossil Fuels to Electricity
Authors: Haupt Guenther , Joyce John S. , Kuenstle Konrad
Published: March 2015

The environmental impact of unfired combined-cycle blocks of the GUD® type is compared with that of equivalent reheat steam boiler/turbine units. The outstandingly high efficiency of GUD blocks not only conserves primary-energy resources, but also commensurately reduces undesirable emissions and unavoidable heat rejection to the surroundings.

In addition to conventional gas or oil-fired GUD blocks, integrated coal-gasification combined-cycle (ICG-GUD) blocks are investigated from an ecological point of view so as to cover the whole range of available fossil fuels. For each fuel and corresponding type of GUD power plant the most appropriate conventional steam-generating unit of most modern design is selected for comparison purposes. In each case the relative environmental impact is stated in the form of quantified emissions, effluents and waste heat, as well as of useful byproducts and disposable solid wastes.

GUD blocks possess the advantage that they allow primary measures to be taken to minimize the production of NOx and SOx, whereas both have to be removed from the flue gases of conventional steam stations by less effective and desirable, albeit more expensive secondary techniques, e.g. flue-gas desulfurization and DENOX systems. In particular, the comparison of CO2 release reveals a significantly lower contribution by GUD blocks to the greenhouse effect than by other fossil-fired power plants.
Modified Exhaust-Heated Gas Turbine Cycle With Increased Thermal Efficiency and its Prospect for Industrial Application
Authors: Golinski Joseph A.
Published: March 2015

A kind of developed exhaust-heated cycle arrangement comprising two or three reheaters and three intercoolers as well as an extra primary air blower (atmospheric combustion) is proposed. As far as classical exhaust-heated cycle is concerned, its thermal efficiency is quite low (15–20%) and therefore, a conception of a developed system provided with additional heat exchangers and combustion chambers has been worked out. The proposed installation operates on natural gas, which is becoming more and more popular now. A numerical example of calculation of a plant of 5250 kW effective power is presented. The “free-shaft” principle has been adopted. All the compressors are driven by a set of two turbines and the other two turbines are used for driving the electric generator. (Extra power that could be obtained from natural gas expander was not taken into account). In general it may be stated that the modified exhaust-heated cycle arrangement may compete with closed cycle turbine arrangements (e.g. Escher Wyss type). Moreover it may — to some extent — be superior to semi-closed cycle arrangements, since in the system proposed all the turbines are driven by compressed air whereas in the semi-closed cycle two turbines are driven by combustion gases.
Gas Turbine Component Fault Identification by Means of Adaptive Performance Modeling
Authors: Stamatis A. , Mathioudakis K. , Smith M. , Papailiou K.
Published: March 2015

The method of adaptive modelling of Gas Turbine performance, proposed in the past by the present authors, is finding a new application in component fault detection. An appropriate choice of component characteristic parameters gives the possibility of characterizing their “health condition”, by appropriate processing of selected measured quantities according to the principles of adaptive modelling. Both a general deterioration of components and identification (kind, location) of component faults can be achieved. The proposed methodology is presented together with an experimental investigation of Gas Turbine faults. A commercial Gas Turbine has been used as a test vehicle and various kinds of faults have been implanted. An analysis of the results of the investigation provides information about the influence of the occurrence of such faults on engine performance. On the other hand, these data provide a basis for demonstrating the capabilities of the above mentioned methodology, as a powerful tool for diagnostic applications.
Coal Gaseous Fueled, Low Fuel-NOx Gas Turbine Combustor
Authors: Sato M. , Ninomiya T. , Nakata T. , Yoshine T. , Yamada M. , Hisa S.
Published: March 2015

From the view point of future coal utilization technology for the thermal power generation systems, the coal gasification combined cycle system has drawn special interest recently. In the coal gasification combined cycle power generation system, it is necessary to develop a high temperature gas turbine combustor using a low–BTU gas (LBG) which has high thermal efficiency and low emissions.

In Japan a development program on the coal gasification combined cycle power generation system has started in 1985 by the national government and Japanese electric companies. In this program, is planned to develop the 1300 °C class gas turbines. However, in the case of using a hot type fuel gas cleaning system, the coal gas fuel to be supplied to gas turbines will contain ammonia. Ammonia will be converted to nitric oxides in the combustion process in gas turbines. Therefore, low fuel–NOx combustion technology is one of the most important research subjects.

This paper describes low fuel–NOx combustion technology for 1300 °C class gas turbine combustor using low BTU coal gas fuel.

Authors have showed that the rich–lean combustion method is effective to decrease fuel–NOx (1). In general in rich–lean combustion method, the fuel–NOx decreases, as the primary zone becomes richer. But flameholding becomes very difficult in even rich primary zone. For this reason this combustor was designed to have a flameholder with pilot flame.

Combustion tests were conducted by using a full scale combustor used in 150 MW gas turbine at the atmospheric pressure condition.
Analysis of Viscous Flowfield Over Tactical Aircraft Forebody and Inlets
Authors: Tseng W. , Findlay D.
Published: March 2015

As the performance requirements of advanced tactical aircraft increase and additional design constraints are imposed, the integration of the engine-airframe becomes critical because it is difficult to provide efficient external aerodynamics, low drag and high maneuverability along with high quality internal flow (i.e high thrust, adequate engine stall margin). To identify or provide warnings about the nonlinear detrimental flow interaction effects associated with engine inlet flow rate, inlet geometry, forebody shape and integration, a computational methodology has been developed to augment the engine-airframe integration process. This paper discusses the use of this methodology to investigate the flow field of the F/A-18 forebody, the X-31A inlet, the YF-16 inlet and the integrated forebody-inlet flow of the YF-16.

First, a discussion of the preprocessor will be presented which prepares the input grid for the flow solver and generates a graphic display of the model for viewing examination. Second, the solution methodology of the governing equation is discussed. Finally, four configurations were analyzed, namely the F/A-18 forebody, X-31A inlet, YF-16 inlet and the YF-16 integrated forebody-inlet with results presented utilizing a post-processor.