bluuebunny/crossref_metadata_2025 huggingface dataset:
Full Surface Local Heat Transfer Coefficient Measurements in a Model of an Integrally Cast Impingement Cooling Geometry
Authors: Gillespie David R. H. , Wang Zuolan , Ireland Peter T. , Kohler S. Toby
Published: February 2015

Cast impingement cooling geometries offer the gas turbine designer higher structural integrity and improved convective cooling when compared to traditional impingement cooling systems which rely on plate inserts. In this paper, it is shown that the surface which forms the jets contributes significantly to the total cooling. Local heat transfer coefficient distributions have been measured in a model of an engine wall cooling geometry using the transient heat transfer technique. The method employs temperature sensitive liquid crystals to measure the surface temperature of large scale perspex models during transient experiments. Full distributions of local Nusselt number on both surfaces of the impingement plate, and on the impingement target plate are presented at engine representative Reynolds numbers. The relative effects of the impingement plate thermal boundary condition and the coolant supply temperature on the target plate heat transfer has been determined by maintaining an isothermal boundary condition at the impingement plate during the transient tests. The results are discussed in terms of the interpreted flow field.
Response of a Turbofan Engine Compression System to Disturbed Inlet Conditions
Authors: Abdel-Fattah Adnan M.
Published: February 2015

A generic code DYNTECC has been adapted to perform a parametric study of the effect of inlet flow distortion on the stability of the Pratt and Whitney TF30 engine. This code was developed at Arnold Engineering Development Center, USA, for single and dual spool systems. It was modified at AMRL to accommodate the particular geometry of the TF30 engine. The stage characteristics needed to operate DYNTECC were derived from experimental data for the fan and low pressure compressor. For the high pressure compressor they were derived using the STGSTK code developed at NASA Lewis Research Center. This program was modified at AMRL to include real flow effects that were in turn derived using yet another adapted code CASCAD. The code was primarily used at AMRL to predict the onset of system instability due to simulated full-face rapid inlet temperature ramps typical of those caused during armament firings. It was also run with sinusoidal total pressure oscillations of varying amplitudes and frequencies at the inlet. The code predictions were compared with available data whenever possible, and were found to be consistent with the observed experimental trends.
High-Accuracy Turbine Performance Measurements in Short-Duration Facilities
Authors: Haldeman Charles W. , Dunn Michael G.
Published: February 2015

This paper describes work done in preparation for the measurement of stage efficiency in a short-duration shock-tunnel facility. Efficiency measurements in this facility require knowledge of the flow path pressure and temperature, rotating system moment of inertia, and mass flow. This paper describes in detail an improved temperature compensation technique for the pressure transducers (Kulite) to reduce thermal drift problems, and measurements of the rotating system moment of inertia. The temperature compensation has shown that the conversion to pressure is accurate to within 0.689 kPa (0.1 psi) over the 40°C test range. The measurement of the moment of inertia is shown to be accurate to within 0.7% of the average value.
The Enhanced TF40B Engine: A Modular Upgrade
Authors: Metz Stephen D. , House Edward M. , Rubenstein Howard
Published: February 2015

The AlliedSignal TF40B engine is used on the U.S. Navy’s Landing Craft Air Cushion (LCAC) for main propulsion. The U.S. Navy is currently supporting the development of an Enhanced version of the TF40B engine which will increase airflow by 17%. There will be a 20% power increase to 5000 SHP and a 7% improvement of specific fuel consumption. The design stresses a kit concept which allows existing TF40B engines to be upgraded to the enhanced configuration and utilizes most of the existing hardware. The overall size and mounting configuration of the engine will not change. The Enhanced TF40B engine will provide capability for growth in many LCAC applications.
LM2500 High Pressure Turbine Blade Refurbishment
Authors: Driscoll Matthew J. , Descar Peter P. , Katz Gerald B. , Coward Walter E.
Published: February 2015

As a cost savings measure, aircraft engine users often have hot section components reconditioned and re-installed during engine rebuilds and overhauls. This paper discusses the United States Navy’s test program to determine the risk/reward potential of refurbishing LM2500 high pressure turbine (HPT) blades. In a parallel effort, various marinized HPT blade coatings will be tested and their performance evaluated. General Electric’s LM2500 gas turbine is the main propulsion engine aboard the US Navy’s newest surface combatants (FFG 7, DD 963, CG 47, AOE 6 and DDG 51 class ships).
Operational Experience With the World’s First Offshore Turboexpanders With Magnetic Bearings
Authors: Underbakke Harald
Published: February 2015

The first offshore turboexpanders with magnetic bearings have now been in operation on the Sleipner A platform in the North Sea since October 1993.

Four machines are installed, each at 3.3 MW, running at 16,500 RPM for natural gas dew point control.

During the commissioning phase and the first year of operation a number of problems were discovered, mainly due to the application of magnetic bearings in a new environment, and some unexpected bearing / process interaction phenomenon.

To solve the problems it was necessary to do modifications to electrical systems, mechanical parts, operational procedures and buffer gas systems.

After a 1.5 year period of modifications, all 4 machines are now running with 99 % availability.
Joining of Wrought Ni-Base Combustor Alloys
Authors: Ritter A. M. , Jackson M. R. , Abuaf N. , Lacey M. A. , Feitelberg A. S. , Lang P.
Published: February 2015

In many advanced combustor concepts, such as the RQL (rich-quench-lean) combustor, the requirement of low NOx emission makes film cooling of the hot gas path surfaces undesirable. Double-walled structures with relatively low aspect ratio (height/width) rectangular passages and with well-controlled thin hot gas side metal walls are an alternative to film cooling. The additional application of other cooling techniques, such as impingement and surface enhancements, make efficient use of the limited cooling air available. However, the use of cooling channels to increase heat transfer coefficients on the coolant side may ultimately require well-bonded structures. Alternate methods of bonding have been considered for Ni-base alloy HA230-to-HA230 joints in thin-walled structures, with emphasis on bonds produced by hot isostatic pressing and by laser welding. For hot isostatic pressed (HIPed) structures, mechanical strength and ductility have been measured as a function of temperature for structures prepared after a number of different surface cleaning treatments prior to joining. The surface cleanliness has been characterized by scanning electron microscopy, and the after-HIP bond line microstructure has been evaluated as formed and after mechanical testing. Characterization of laser welds produced at Laserdyne for Acraline Products has consisted of scanning electron microscopy of the weld surfaces and metallography of weld/substrate cross-sections, looking at solidification/heat affected features and defects.
Three Dimensional Analysis of Advanced Swirl Vane/Nozzle Assemblies
Authors: Micklow Gerald J. , Benjamin Michael
Published: February 2015

The performance of high shear axial inflow/radial outflow airblast fuel injectors for advanced gas turbine combustors is highly dependent on the design of the swirl vanes. Curved vanes usually exhibit lower losses but straight vanes are also used due to lower cost and ease of manufacture. These type of vanes often operate under highly stalled conditions with high total pressure loss and a highly non-uniform exit velocity profile. This may produce poor fuel atomization with a non-uniform combustor fuel distribution resulting in lowered combustor efficiency and increased pollutant emissions.

Properly designed vanes result in a greatly reduced total pressure loss. The exit velocity distribution is more uniform and higher in magnitude which can result in improved fuel atomization and distribution in the combustor.

The present study investigates two curved swirler/nozzle shroud configurations operating at 1 and 10 atmospheres pressure for the same inlet temperature of 293°K. The first configuration was a twisted curved vane with thickness where the turning angle varied non-linearly from hub to tip with a maximum turning at the tip of 70 degrees. The second configuration was a curved vane with a linear variation of turning with 70 degrees turning at the tip. The results from a three dimensional viscous numerical flow simulation of these configurations shows similar performance for all cases investigated. The non-linear twisted vane however, had an approximately 3% higher mass flow rate than the vane with the linear variation in turning for the same exit static pressure at the hub. One problem which existed for all the conditions analyzed was a high loss region near the vane tip. This was due to the interaction with the shroud. As the flow exits the vane row and progresses along the nozzle outer lip, the flow area increases. This condition along with the streamline curvature effect of the outer nozzle lip causes an adverse pressure gradient to be formed in this region. This adverse pressure gradient causes the flow to separate from the vane suction surface. The problem initiated in the region of 70% span and increased in magnitude to the vane tip.
Reynolds Stress Tensor Measurements in a Centrifugal Compressor Vaned Diffuser
Authors: Pinarbasi Ali , Johnson Mark W.
Published: February 2015

Measurements of the full Reynolds stress tensor have been made throughout the vaned diffuser of a low speed centrifugal compressor. Results are presented close to the impeller exit plane and the vane leading edge plane at three inter vane positions. The results show that the vanes have a significant influence on the flow in the vaneless space. The mixing out of the blade wakes is enhanced and hence the Reynolds stress levels drop rapidly between the impeller exit and the vane leading edge. The flow also exhibits high levels of anisotropicity, particularly at the mid-vane position. This suggests that standard turbulence models are inadequate for modelling these flows using CFD and full Reynolds stress turbulence models are required.
Westinghouse Combustion Turbine Performance in Coal Gasification Combined Cycles
Authors: Newby Richard A. , Bannister Ronald L. , Miao Frank
Published: February 2015

Combustion turbines, designed for conventional turbine fuels, are adaptable to low- and medium-Btu coal syngases if appropriate fuel gas cleaning is provided. Evaluations have been conducted on the performance of integrated gasification combined cycles (IGCC) using Westinghouse 501F and 501G combustion turbines, and the next-generation Westinghouse combustion turbine system, the ATS. Several major IGCC process variations have been considered. The estimated cycle efficiencies are competitive with alternative coal-fueled power generation technologies when using conventional cold syngas cleaning. Optimized coal gasification combined cycle air and steam integration is key to achieving competitive plant efficiency and economics.
Application of Advanced Experimental Techniques in the Development of a Cooled Turbine Nozzle
Authors: Moon H. K. , Glezer B.
Published: February 2015

In spite of very significant progress in analytical and numerical methods during recent years, experimental techniques are still essential tools for the development of cooled turbine nozzles. This paper describes the major elements of the development process for cooled turbine nozzles with a primary emphasis on advanced experimental heat transfer techniques. Thermochromic liquid crystals were used to measure the internal (coolant side) heat transfer coefficients of a practical vane cooling design which has a combination of different heat transfer augmenting devices. A comparison of the results and analytical predictions provided validations of existing correlations which were developed from the generic cases (usually one type of augmenting device). The overall cooling design was evaluated in a full-scale annular hot cascade which maintained heat transfer similarity. The freestream turbulence level was measured with an in-house developed heat flux probe. Cooling effectiveness distribution was evaluated from the surface metal temperatures mapped with an in-house developed wide range temperature pyrometer. The test results led to the fine-tuning of the nozzle vane cooling design.
Optimization of Transient Heat Transfer Measurements Using Thermochromic Liquid Crystals Based on an Error Estimation
Authors: Höcker Rainer
Published: February 2015

An analytical investigation has been made to identify and quantify critical parameters influencing the final result of a transient heat transfer experiment. The aim was to obtain a set of dimensionless parameters, that describe the interaction of the individual measured quantities in a compact form.

Among the wide variety of different kinds of heat transfer measurement techniques, the transient method, employing thermochromic liquid crystals, is very useful. It gives much detailed heat transfer information with a minimum effort in experimental time. The present paper focuses on this technique, although it is not the only choice for all kinds of applications, but it is the currently most frequently used one.

This paper provides the means to lay out an experiment, so that it yields acceptable results with respect to the constraints for a set of test boundary conditions.
PIV Measurements of Periodically Forced Flat Plate Film Cooling Flows With High Free Stream Turbulence
Authors: Gogineni Sivaram P. , Trump Darryl D. , Rivir Richard B. , Pestian David J.
Published: February 2015

Two color double pulsed Particle Image Velocimetry (PIV) measurements of simulated turbine film cooling flows have been made for blowing ratios of 0.5, 0.7, and 1.0 in the near field of the film cooling hole, x/d≤2.5. The effect of the vane wake on the rotor film cooling flow is simulated by periodically forcing the film cooling flows at the nnn dimensional reduced frequency. Phase locked measurements at 45 deg. increments of the periodic film forcing (0, 45, 90, 135, 180, 225, 270, and 315 deg.) for free stream turbulence levels of 1 and 17% have been made. The effects of reduced frequencies of 20 and 80, at free stream turbulence levels of 1 and 17% on the spreading of the film cooling jet are investigated. Increases in the jet spread with forcing and free stream turbulence are > 2 times those in the unforced 1% free stream turbulence case.
Comparisons of Rig and Engine Dynamic Events in the Compressor of an Axi-Centrifugal Turboshaft Engine
Authors: Owen A. Karl , Mattern Duane L. , Le Dzu K.
Published: February 2015

Steady state and dynamic data were acquired in a T55-L-712 compressor rig. In addition, a T55-L-712 engine was instrumented and similar data were acquired. Rig and engine stall/surge data were analyzed using modal techniques. This paper compares rig and engine preliminary results for the ground idle (approximately 60% of design speed) point. The results of these analyses indicate both rig and engine dynamic events are preceded by indications of traveling wave energy in front of the compressor face. For both rig and engine, the traveling wave energy contains broad band energy with some prominent narrow peaks and, white the events are similar in many ways, some noticeable differences exist between the results of the analyses of rig data and engine data.
Invariant Coordinate Systems for Compressor Control
Authors: Batson B. W.
Published: February 2015

To protect a compressor from surge, it is necessary to accurately calculate the location of the interface between stable operation and surge. Describing the Surge Limit Interface in certain coordinate systems results in a surface which is invariant to compressor suction conditions such as temperature and molecular weight. We refer to these coordinates as invariant coordinates. We explore these invariant coordinate systems and some nearly invariant systems useful for antisurge control. Some of them are commonly used in the industry, others are quite novel. This work serves to point out the unifying basis of them all.

The applications for these methods are mainly industrial compressors. Varying molecular weight represents the main challenge since a real-time measurement for this parameter is unavailable.

We present compressor maps constructed from test data in these coordinates. The validity of this approach is well supported by these data.
Actuator Placement for Active Surge Control in a Multi-Stage Axial Compressor
Authors: Montazeri-Gh. M. , Allerton D. J. , Elder R. L.
Published: February 2015

This paper describes an actuator placement methodology for the active control of purely one-dimensional instabilities of a seven-stage axial compressor using an air bleeding strategy. In this theoretical study, using stage-by-stage non-linear modelling based on the conservation equations of mass, momentum, and energy, a scheduling LQR (Linear Quadratic Regulator) controller is designed for several actuator locations in a compressor from the first stage to the plenum. In this controller design, the LQR weighting matrices are selected so that the associated cost function includes only air bleeding mass flow leading to the minimisation of the air bleed. The LQR cost function represents a measure of the consumption of air bleeding and can be calculated analytically using the solution of an Algebraic Riccati Equation. From analysis of the cost at different compressor stages, the location of an air bleeding actuator is selected at the stage with the minimum cost. Finally, using an ACSL simulation program, the scheduling controller has been integrated with a non-linear. stage-by-stage model and the time response of the air bleeding mass flow at different locations has been obtained to confirm the results from the analytical approach. Results are presented to show actively stabilised compressor flow beyond the surge point where the air bleed is minimised. These results also indicate the preferred location of the actuator at the compressor downstream stages for both low and high compressor speeds.
Experimental Research on the Aerodynamic Performances of 2-D Lobed Exhaust Ejector Systems
Authors: Hu Hui , Liu Huoxing , Li Li , Wu Shousheng
Published: February 2015

Experimental research for seven exhaust ejector system combinations, including four two-dimensional (2-D) lobed nozzles and three 2-D mixing tubes, has been conducted to investigate the effect of the lobe structure on the aerodynamic performances of the ejector systems. Test results show that: 2-D eligned lobed nozzles have better pumping and mixing enhancement abilities than the 2-D staggered lobed nozzles, but they also cause bigger pressure losses; the 2-D lobed nozzle with equal lobe width have better aerodynamic performances than the 2-D lobed nozzle with bigger inner lobe width. 2-D aligned scalloped lobed nozzle has the best pumping and mixing enhancement performances, but it also has the biggest pressure loss coefficient. Among the tested combinations, the combination of 2-D staggered lobed nozzle with equal lobe width and 2-D mixing tube with multiple-ring cooling structure has the best combined aerodynamic performances.
Hydrogen-Fueled Combustion Turbine Cycles
Authors: Bannister Ronald L. , Huber David J. , Newby Richard A. , Paffenbarger John A.
Published: February 2015

As part of its World Energy Network (WE-NET) Program, the Japanese New Energy and Industrial Technology Development Organization (NEDO) is funding a Westinghouse-led team to develop conceptual designs of hydrogen-fueled combustion turbine power plants capable of greater than 60% high heating value (HHV) thermal efficiency. The conceptual design task is taking place in the second year of the 28-year program, which has the goal of developing a hydrogen-based renewable energy economy. Due to the requirement that the power plant must be environmentally benign, special closed cycles are being investigated which will meet the requirements of the program while allowing for pilot plant testing in the near future. This paper investigates a variety of possible cycle configurations and working fluids and describes the selection methodology used to identify the best candidate. Optimization of the selected cycle is then described, which results in the basis for the conceptual design.
Passage Flow Structure and its Influence on Endwall Heat Transfer in a 90° Turning Duct: Turbulent Stresses and Turbulent Kinetic Energy Production
Authors: Wiedner Brian G. , Camci Cengiz
Published: February 2015

The complex interaction between three-dimensional passage flow structure and endwall convective heat transfer in a square cross section, 90° turbulent duct flow has been experimentally investigated. Fine details of the momentum and heat transport process in a laboratory model that simulated a high Reynolds number three-dimensional passage flow are presented. The specific flow and heat transfer mechanisms are frequently encountered in the hot mainstream of axial flow turbines and internal coolant passages. Similar physical phenomena may also be observed in many other fluid machinery systems. The mean radius to duct width ratio was 2.3 and the Reynolds number based on inlet center line velocity, duct width, and ambient conditions was approximately 360,000. The complete Reynolds stress tensor was measured using a triple sensor hot wire. The turbulent normal and shear stresses, turbulent kinetic energy, and production of turbulent kinetic energy are presented. A steady state heat flux measurement technique and liquid crystal thermography were used to determine the character of the endwall heat transfer in the form of a high resolution heat transfer map. The flow field was dominated by strong counter rotating secondary flows characteristic of 90° turning ducts. The flow structure also included areas of strong streamwise accelerations and decelerations, high vorticity, local regions of significant total pressure loss, and a complex turbulent flow field structure. The development of the turbulent features of the 90° turning duct flow field and the influence of the turbulent flow field on the endwall convective heat transfer distribution are discussed. The multi-dimensional flow and high resolution heat transfer results are currently being incorporated in computational aerothermal models under development at Penn State University. The results are also available as a data base for future aerothermal model validation studies.
Impact of Rotor Wakes on Steady-State Axial Compressor Performance
Authors: Deregel P. , Tan C. S.
Published: February 2015

This paper addresses the causal link first described by Smith between the unsteady flow induced by the rotor wakes and the compressor steady-state performance. As an initial step, inviscid flow in a compressor stage is examined. First of a kind numerical simulations are carried out to show that if the rotor wakes are mixed out after (as opposed to before) the stator passage, the time-averaged overall static pressure rise is increased and the mixing loss is reduced. An analytical model is also presented and shown to agree with the numerical results; the model is then used to examine the parametric trends associated with compressor design parameters.
Cooling and Sealing Air System in Industrial Gas Turbine Engines
Authors: Reichert A. W. , Janssen M.
Published: February 2015

Siemens heavy duty Gas Turbines have been well known for their high power output combined with high efficiency and reliability for more than 3 decades. Offering state of the art technology at all times, the requirements concerning the cooling and sealing air system have increased with technological development over the years. In particular the increase of the turbine inlet temperature and reduced NOx requirements demand a highly efficient cooling and sealing air system. The new Vx4.3A family of Siemens gas turbines with ISO turbine inlet temperatures of 1190°C in the power range of 70 to 240 MW uses an effective film cooling technique for the turbine stages 1 and 2 to ensure the minimum cooling air requirement possible. In addition, the application of film cooling enables the cooling system to be simplified. For example, in the new gas turbine family no intercooler and no cooling air booster for the first turbine vane are needed.

This paper deals with the internal air system of Siemens gas turbines which supplies cooling and sealing air. A general overview is given and some problems and their technical solutions are discussed. Furthermore a state of the art calculation system for the prediction of the thermodynamic states of the cooling and sealing air is introduced. The calculation system is based on the flow calculation package Flowmaster (Flowmaster International Ltd.), which has been modified for the requirements of the internal air system. The comparison of computational results with measurements give a good impression of the high accuracy of the calculation method used.
Fully-Developed Buoyancy-Affected Flow and Heat Transfer in an Axially Rotating Annular Channel With Longitudinal Partitions
Authors: Khodak Andrei E. , Kirillov Alexander I. , Ris Vladimir V. , Smirnov Evgeni M.
Published: February 2015

Navier-Stokes equations written in the Boussinesq’s approximation are solved numerically for simulation of the laminar and turbulent flows of the cooling air through a long gap between two co-rotating cylinders kept at different temperatures. Flow situations with Grashof numbers up to 107, are considered. Data on velocity and temperature fields as well as on local Nusselt number distributions and averaged heat transfer have been obtained for a 60° sector. It has been established that the spanwise size of buoyancy-driven vortices developing in a 60° sector channel changes significantly over the gap in case of laminar flow and remain nearly constant for turbulent flow. For the laminar regime, the cross flow intensity is approximately ten times higher than for turbulent flows at the Reynolds numbers of the order of 104. Some computations have been performed using a simplified single-cell formulation.
Jet, Wake and Intrinsic Motion in Impellers of Centrifugal Compressors
Authors: Chen Y. N. , Seidel U. , Haupt U. , Rautenberg M.
Published: February 2015

It was shown in a previous paper of the authors (1991) that jet and wake in the flow of the impeller of the centrifugal compressor are developed from the Dean’s type vortex pair formed in the curvature of the blade channel. The jet rotating against the sense of the impeller is weakened, and the wake rotating in the sense of the impeller is enhanced during travelling with the flow toward the outlet. This property is attributed to the conservation of the potential vorticity of the vortex. The experimental result obtained by Krain (1984) has confirmed this theory.

The secondary flows found by Farge and Johnson (1990) enable the determination of the vorticity of the wake at the outlet of the impeller. It amounts to 6.9 Ω and 5.8 Ω for the radial-blading and the 60°-backswept blading impeller, respectively. The intensity of the vortex jet is weakened to undetectable value for both the impellers. The patterns of these secondary flow fields are also quite different between these two kinds of impellers. Whilst that of the former is controlled by the intrinsic motion, that of the latter is governed by the relative velocity along the blades.

Furthermore, the experimental result obtained by the injection of colored dye at the impeller outlet and the measured velocity field around the impeller reveal an intense reverse flow in the radial blading impeller, travelling from the outlet toward the inlet, along the shroud. It can be shown that this reverse flow is caused by the intrinsic motion occuring in this impeller and impinging on the leading edge of the diffuser vane. As the rotating stall is introduced by the reverse flow, the low-solidity vaned diffuser, and still better the vaneless diffuser can therefore shift the stall line to a very low flow rate.
Stage-by-Stage Dynamic Compression System Modeling for Split Core and Bypass Systems
Authors: Lindau Jules W. , O’Brien Walter F.
Published: February 2015

A method for solving a set of equations for one-dimensional stage-by-stage dynamic compression system modeling was applied to a two-dimensional post-stall model. The model is suitable for capturing the flow during surge in split flow systems such as tuibofans and, possibly, in centrifugal compressors. The modeling requires the solution of a modified form of the Euler equations in axisymmetric form. A robust solution method was facilitated by the use of a special form of upwind flux, flux difference splitting with source terms (FDSS), and implicit time integration. The modeling method was applied to the simulation of a split flow-path fan system and results are presented.
Role of Environmental Deposits in Spallation of Thermal Barrier Coatings on Aeroengine and Land-Based Gas Turbine Hardware
Authors: Borom Marcus P. , Johnson Curtis A. , Peluso Louis A.
Published: February 2015

Thermal barrier coating (TBC) spallation on power generation combustors was compared with TBC spallation observed both in military turboshaft engines, and in commercial turboprop engines. In each case, irrespective of operating conditions or geographic location, spallation was linked to the presence and infiltration of high temperature molten phases of similar composition. Electron microprobe analysis found that, from all the possible oxides available in the external environment, only CaO, MgO, Al2O3 and SiO2 (CMAS) are incorporated in the molten phase that infiltrates the TBC microstructure. Iron and nickel oxides from turbine components and zirconia and yttria from the TBC were also found in varying amounts in the molten phase.

Melting of environmental deposits in conjunction with infiltration was found to result in: densification of the TBC, an increase in its Young’s modulus and an increase in the room temperature compressive stress in the TBC. Delamination of the TBC during thermal cycling is, thereby, attributed to changes in the mechanical properties and associated changes in the stress state of the coating due to infiltration of the environmental deposit.
Silicon Nitride Components for AGATA: A European Gas Turbine for Hybrid Vehicles
Authors: Lundberg Robert , Adlerborn Jan
Published: February 2015

The European EUREKA project, EU 209, otherwise known as AGATA (Advanced Gas Turbine for Automobiles), is a programme dedicated to the development of three critical ceramic components — a catalytic combustor, a radial turbine wheel and a static heat exchanger — for a 60 kW turbogenerator in an hybrid electric vehicle. These three components, which are of critical importance to the achievement of low emissions and high efficiency, will be designed, developed, manufactured and tested as part of a full scale feasibility study. AGATA is a joint project conducted by eight commercial companies and four research institutes in France and Sweden. Silicon nitride ceramics play an important role both in the development of the catalytic combustor and for the radial turbine wheel. This paper outlines the main results of the AGATA project with special emphasis to the development of Si3N4 combustor and turbine wheel.
Multivariable Control of Industrial Gas Turbines: Field Test Results
Authors: Rajamani Ravi , Norman Bruce G.
Published: February 2015

Rejecting, or reducing, the effect of external disturbances on process parameters is an important problem in control design. In this paper we apply multivariable control techniques to reduce the effect of input disturbances, such as variations in the line frequency, on key internal parameters of an industrial gas turbine. The parameter we are most interested in is the combustion reference temperature, an estimated variable that is used by the controller to schedule division of fuel to various fuel nozzles and determine switching points between combustion modes. The dynamic response of this parameter correlates well with the dynamic response of fuel air ratio inside the combustor. Therefore, an important step in improving combustor performance is better regulation of the combustion reference temperature. We show that the use of a multivariable controller in place of the existing decentralized controller makes the disturbance rejection problem much easier to solve. As the gas turbine is inherently a multivariable system — i.e. the inputs, fuel and air, are coupled to the outputs, power and exhaust temperature — this result is not entirely surprising. We use a frequency domain, control design technique known as the Edmund’s method. The linear models are obtained using system identification techniques. We present results from a field test of the controller (implemented on a GE Frame 7E turbine) in the form of data comparing the response of the multivariable controller with that of the existing (decentralized) controller. These results clearly show that by using a multivariable controller the effects of the external disturbances can be reduced by a factor of 3 when compared with the existing design.
User-Oriented Gas Turbine Research at KEMA
Authors: Rooth R. A.
Published: February 2015

In the 80’s and early 90’s, in the Netherlands 11 combi blocks with prefitted gas turbines have been built. This repowering programme increased the efficiency of the units involved by several percentage points. Additionally, the commissioning of the five 335 MWe units at the Eems power station is in progress and plans exist for a farther seven 250 MW heat and power stations. This means that by 2002 the generating industry will be operating seventy-five gas turbines with a total gas turbine power of 5700 MWe. These data serve to illustrate mat gas turbines will be the workhorse of the Dutch generating industry in the coming decades, and that security of supply, efficiency, emissions and generating cost will to a large extent be determined by the gas turbine. However, the introduction of the gas turbine, driven by the possibility of high-efficiency electricity generation in e.g. combined cycle units, the increase in scale of the machines and the fact that they are increasingly being used in base load units have also led to problems and forced unavailability, as will be shown under goals of the project. The problems are related to creep, thermal stresses and fatigue of combustion chambers, turbine rotor blades, rotors etc. Apart from these problem areas, other subjects of interest are optimization of inlet air filtering and compressor cleaning. It is the Dutch Electricity Production industry who realized that a substantial R&D effort is necessary to solve those user related problems and formulated the execution of the target project Gas Turbines.
Design of the Tempest Industrial Gas Turbine
Authors: Scott Kevin R. , Amos Ian G. , Garbett Paul D. P. , Wells Roger G.
Published: February 2015

The Tempest is the most recent power generation package produced by European Gas Turbines in England. It is currently in the evaluation phase of a 3 year program leading to production in 1996 at 7.5MWe and single-shaft configuration.

The machine has been designed for base load operation using gas and liquid fuels and is particularly suitable for combined heat and power applications. It is a development of the existing Typhoon and Tornado family of engines but includes a number of features to enhance its performance.

This paper discusses the design techniques and describes the gas turbine engine core. It also presents the design validation and service recommendations.
Development of Advanced Gas Turbine
Authors: Matsuzaki H. , Suto Y. , Kanazawa Y. , Sato M. , Kobayashi I. , Kobayashi Y.
Published: February 2015

There is a strong demand for efficient and clean power generation systems which can cope with the energy shortage and the global environmental problems.

As one of the measures to meet this demand, Tohoku Electric Power Company, in cooperation with the three domestic gas turbine manufacturers, has been developing since 1989 the key technologies for the next generation high efficiency gas turbine of a 1,500°C class of firing temperature.

The aim is to achieve over 55% (LHV) thermal efficiency in a LNG comhined cycle power plant.

In this research, Tohoku Electric Power Company have developed: (1) advanced cooling schemes for 1st stage vanes and blades, (2) heat resistant materials for 1st stage vanes and blades and (3) high temperature low NOx combustor, which are the key technologies required for realizing a 1,500 °C class high efficiency gas turbine with a potential for practical use.
Numerical Simulation of Particulate Two-Phase Flows in Curved Pipeline Geometries
Authors: Naik S.
Published: February 2015

The flow of particulate two-phase flow mixtures occur in several components of solid fuel combustion systems, such as the Pressurised Fluidised Bed Combustors (PFBC) and suspension fired coal bailers. A detailed understanding of the mixture characteristics in the conveying component can aid in refining and optimising its design. In this study, the flow of an isothermal, dilute two-phase particulate mixture has been examined in a high curvature duct, which can be representative of that transporting the gas-solid mixture from the hot clean-up section to the gas turbine combustor in a PFBC plant.

The numerical study has been approached by utilising the Eulerian-Lagrangian methodology for describing the characteristics of the fluid and particulate phases. By assuming that the mixture is dilute, the governing particle momentum equations have been solved with appropriately prescribed boundary conditions. The influence of the turbulence on the particle dispersion was represented by a stochastic model.

For the turbulent flow condition examined, it was observed that mixtures with small particle diameters had low inter-phase slip velocities and low impaction probability with the pipe walls. Increasing the particle diameters (> 50 um) resulted in higher inter-phase slip velocities and as expected their impaction probability with the pipe walls was significantly increased. The particle dispersion is significant for the smaller sizes whereas the larger particles are relatively insensitive to turbulence. The main particle impaction region, and location most prone to erosion damage, is estimated to be within an outer duct length of 2 to 5 times the duct diameter.
Manufacturing Methods, Random Defects and Quality Assurance in Relation to the Reliability of Turbine Components
Authors: Mitchell A.
Published: February 2015

The present methods for life prediction in rotating parts rely heavily on an assumed distribution of potential crack initiation sites, corresponding to a distribution of properties which is determined from laboratory testing of samples of the alloy. However, as the expectations of the designer extend into increasing reliable life and also come closer to the limits of alloy performance, we also approach the limits of validity of the statistical methods used in property specification, raising the problem of the rare random defect which may be present in spite of the installed production control methodologies. This type of defect may be found in all alloys, but the specific form depends on the alloy and on the manufacturing method. In this work we give examples for high-strength steels, superalloys and titanium alloys.

We propose that the most effective solution to this problem lies in the more vigorous application of process control within manufacturing fixed practices, ensuring the absence of this type of defect through control and data acquisition techniques which can identify a process anomaly and trigger rejection or down-grading of the product.
Flow in a Rotating Cavity With a Peripheral Inlet and Outlet of Cooling Air
Authors: Gan Xiaopeng , Mirzaee Iraj , Owen J. Michael , Rees D. Andrew S. , Wilson Michael
Published: February 2015

In some engines, corotating gas–turbine discs are cooled by air introduced at the periphery of the system. The air enters through holes in a stationary peripheral casing and leaves through the rim seals between the casing and the discs. This paper describes a combined computational and experimental study of such a system for a range of flowrates and for rotational Reynolds numbers of up to Reϕ = 1.5 × 106. Computations are made using an axisymmetric elliptic solver, incorporating the Launder–Sharma low–Reynolds–number k–ε turbulence model, and velocity measurements are obtained using laser–Doppler anemometry.

The stationary peripheral casing creates a recirculation region: there is radial outflow in boundary layers on the discs and inflow in the core between the boundary layers. The radial extent of the recirculation region increases as the flow rate increases and as the rotational speed decreases. In the core, the radial and tangential components of velocity, Vr and Vϕ, are invariant in the axial direction, and the measured values of Vϕ conform to a Rankine–vortex flow. The agreement between the computed and measured velocities is not as good as that found for other rotating–disc systems, and deficiencies in the turbulence model are believed to be responsible.
Development of an Aeroelastic Code Based on an Euler / Navier-Stokes Aerodynamic Solver
Authors: Bakhle Milind A. , Srivastava Rakesh , Stefko George L. , Janus J. Mark
Published: February 2015

This paper describes the development of an aeroelastic code (TURBO-AE) based on an Euler / Navier-Stokes unsteady aerodynamic analysis. A brief review of the relevant research in the area of propulsion aeroelasticity is presented. The paper briefly describes the original Euler / Navier-Stokes code (TURBO) and then details the development of the aeroelastic extenstons. The aeroelastic formulation is described. The modeling of the dynamics of the blade using a modal approach is detailed, along with the grid deformation approach used to model the elastic deformation of the blade. The work-per-cycle approach used to evaluate aeroelastic stability is described. Representative results used to verify the code are presented. At the present stage of development, the aeroelastic code is limited to in-phase blade motions. The paper concludes with an evaluation of the development thus far, and some plans for further development and validation of the TURBO-AE code.
The Design and Evaluation of a 14 Stage, 16:1 Pressure Ratio Compressor for an Industrial Gas Turbine
Authors: Saadatmand Mohammad R.
Published: February 2015

The aerodynamic design process leading to the production configuration of a 14 stage, 16:1 pressure ratio compressor for the Taurus 70 gas turbine is described. The performance of the compressor is measured and compared to the design intent. Overall compressor performance at the design condition was found to be close to design intent. Flow profiles measured by vane mounted instrumentation are presented and discussed.

The flow through the first rotor blade has been modeled at different operating conditions using the Dawes (1987) three-dimensional viscous code and the results are compared to the experimental data. The CFD prediction agreed well with the experimental data across the blade span, including the pile up of the boundary layer on the corner of the hub and the suction surface. The rotor blade was also analyzed with different grid refinement and the results were compared with the test data.
Sea Trials/Commissioning of a Gas Turbine Powered High Speed Passenger Vessel
Authors: Waldhelm Chris , Warren Nigel
Published: February 2015

The demand for higher vessel speeds and passenger comfort have led to the development of improved hull designs in conjunction with power plants of high specific power and low emissions capabilities inherent in gas turbines. In early 1993, FBM Marine began design and construction of a 45 meter Solent class hulled catamaran with a partial third hull, named TriCat, for 332-passenger service at greater than 45 knots. The power plant selected consists of two Solar Turbines Taurus 60M industrial derivative marine gas turbines driving KaMeWa AB Series 90S11 waterjets through Philadelphia Gear Corporation 1000 VMGH-HP2S speed reduction drives for a total shaft output power of 10.2 MW (equivalent ISO with inlet and exhaust losses).

The Taurus 60M gas turbines, each ISO rated at 5250 kW MCR (without losses), the gearbox and control system were type approved and certified by Det Norske Veritas (DNV) in 1994 prior to issuance of the Certificate of Conformity of the total propulsion package. The sea trials of the TriCat were initiated late 1994 off the Isle of Wight in the UK. After Honk Kong Marine Department approval in early 1995, the owner/operator of the five vessels, CTS-Parkview, began passenger service in June 1995 between Hong Kong and Macau.

This paper discusses the sea trials and commissioning process including improvements incorporated prior to initiation of passenger service on the TriCat.
Endurance Testing of Marine Gas Turbines for the Royal Navy
Authors: McCartney Clive , Hughes Robin D.
Published: February 2015

Royal Naval policy since 1967 has been to employ gas turbines for major surface warship propulsion. In support of this policy, all new engines have been subject to endurance testing at DTEO Pyestock.

Marinised Tyne and Olympus aero engines were tested during the 1960s and 70s which confirmed their initial suitability for RN service and uprated performance. Lessons learnt in formulating the test process were applied to the Spey SMIA engine programme in 1982. Further refinements, following comparison of sea operating experience with test bed results were applied to the 3000 hour endurance trial of the 18 MW Spey SMIC engine, which completed in 1993.

The current testing at Pyestock is of the 21.6 MW Intercooled Recuperated (1CR) WR21 engine, presently under development for the USN in cooperation with the RN. The endurance trials being planned will require a further change in emphasis in order to address the unique operating regimes of an 1CR engine.

The paper describes the evolution of endurance testing techniques, highlighting the particular requirements for complex cycle engines and discusses the opportunities that arose for piggyback trials during typical endurance testing regimes.
Partial Regenerative Steam Injected Gas Turbine
Authors: Uji Shigekazu
Published: February 2015

Steam injection has been employed in gas turbines for over twenty-five years for power increase (more than 50% on some gas turbines) and efficiency improvements (more than 20%). For further improvement of efficiency on steam injected gas turbine, Partial Regenerative Steam Injected Gas Turbine was studied.

Cycle analysis was carried out for the evaluation of efficiency among three systems, Steam Injected Gas Turbine, Regenerative Steam Injected Gas Turbine and Partial Regenerative Steam Injected Gas Turbine. Results of the analysis show that Partial Regenerative Steam Injected Gas Turbine can realize higher efficiency than other two systems.

In addition to the cycle analysis, the effect of applying the concept of Partial Regenerative Steam Injected Gas Turbine to the actual engine Allison gas turbine model 501-KH was evaluated. And the effect of integrating compressor inter-cooling process in Partial Regenerative Steam Injected Gas Turbine was also evaluated.