bluuebunny/crossref_metadata_2025 huggingface dataset:
A Parametric Study of Heat Pipe Turbine Vane Cooling
Authors: Zuo Z. J. , Faghri A. , Langston L.
Published: December 2014

This work investigates the effects of various parameters (geometric dimensions, working fluid, external heating and cooling conditions) on heat transfer performance of the heat pipe turbine vane. This parametric study is based on a numerical model which includes an one-dimensional vapor flow and a three-dimensional wall heat conduction. Heat transfer performance of the heat pipe turbine vane is represented by several parameters including the overall heat transfer coefficient, the temperature ratio, the cooling ratio and the ratios of performance limitations. It is shown that these performance parameters are sensitive to geometric dimensions, working fluid, and external heat transfer coefficients of the heat pipe turbine vane. Information resulting from this study can be used as guidance for design, test and operation of the heat pipe turbine vane.
A Metal Matrix Composite Damage and Life Prediction Model
Authors: Ahmad Jalees , Santhosh Unnikrishnan , Hoff Sandra
Published: December 2014

A simple analytical model is derived for the prediction of time dependent deformation and damage response of metal matrix composites under fiber direction loading. The model can be used in conjunction with a number of viscoplastic constitutive models to describe the matrix material behavior. Damage in the form of progressive fiber fractures is incorporated using a mechanistic approach. The criterion for fiber fractures can be based on statistical information on fiber strength. When used in conjunction with a prescribed failure condition for a composite, the model provides a means for predicting composite life under general thermomechanical load conditions. Based on comparison of results with detailed finite element analyses and with laboratory test data, it appears that the simple model provides reasonably accurate predictions.
Studies on Wake-Disturbed Boundary Layers Under the Influences of Favorable Pressure Gradient and Free-Stream Turbulence: Part I — Experimetal Setup and Discussions on Transition Model
Authors: Funazaki Ken-ichi , Kitazawa Takashi , Koizumi Kazuyuki , Tanuma Tadashi
Published: December 2014

The objective of this study is to investigate effects of favorable pressure gradient as well as free-stream turbulence upon wake-induced boundary layer transition on a flat plate. Likewise in the previous study by Funazaki (1996), a spoked-wheel type wake generator is employed in this study. Two identical flat plates with sharp edge are used as test model. One of them is for measurement of boundary layers over the test plate by use of a single hot-wire probe, and the other is provided with thin stainless-steel foils on the surface to measure wake-affected heat transfer along the surface. Free-stream turbulence intensities are controlled with several types of turbulence grids. Pressure gradients over the test surface are adjusted by changing an inclination angle of the plate located opposite to the test model. In Part I, transition models proposed by Mayle and Dullenkopf (1990b) and Funazaki (1996a, 1996b) are compared with the experimental data obtained in this study to examine how such a model succeeds or fails in predicting the wake-induced boundary layer transition under the influences of favorable pressure gradient with a low free-stream turbulence.
The Impact of Machining Techniques on Centrifugal Compressor Impeller Performance
Authors: Childs P. R. N. , Noronha M. B.
Published: December 2014

A large proportion of modern centrifugal impellers are machined from solid forgings rather than made from cast metal. The CNC milling process offers options to manufacturers to minimise manufacturing costs whilst also enhancing performance of the impeller. Efficient manufacturing can result in cutter tool marks and paths and associated roughness remaining on the hub and blade surfaces of impellers as a result of minimising passes and maximising the cut. The goal of manufacturers is to allow these marks to be as deep as possible to minimise machining costs but without any negative effects in performance and possibly even enhancing it. There are existing modelling methods that predict the influence of roughness on compressor performance using the definition of an equivalent sand grain roughness. The purpose of this study is to relate the performance directly to the tool mark characteristics that are by-products of machining, namely cusp height, cutter path roughness and orientation of the cutter path relative to the local flow velocity, to review the current modelling techniques for predicting the influence of surface condition on compressor performance and to show the scope for optimisation of manufacturing and performance considerations.
Multivariate Experiments to Assess the Effect of Combustor Dome Geometry on Fuel Distribution and Stability
Authors: Arellano Leonel , Ateshkadi Arash , Fukushima Hirokazu , McDonell Vincent G. , Samuelsen Scott
Published: December 2014

The geometric and operational features of gas turbine engine combustors are receiving increased scrutiny due to a growing concern regarding environmental impact, performance, durability, and manufacturability. To minimize the risk associated with new projects, optimization of designs which are similar to those in current operation is attractive. To achieve this goal, a methodology that is efficient and can reveal interactions between parameters that affect performance is necessary. An approach which addresses these requirements is statistically designed experiments (e.g., multivariate experiments or “design of experiments”), which offers efficiency as well as the ability to identify interactions between variables. This approach was adopted and demonstrated in the present study utilizing a set of hardware specifically developed to allow multivariate experiments to be conducted. A radial mixer geometry consisting of four parameters (primary and secondary swirl vane angles, the presence of a venturi, and the co-/counter swirl sense) was examined. The design was developed to maintain constant effective area and overall dimensions. The responses selected for study were stability (i.e., reaction lean blow-out) and fuel distribution.

The results reveal that (1) the multivariate approach is effective in the present application, (2) the swirl sense between the primary and secondary swirlers play an influential role in determining the uniformity of the spray, (3) the size of the fuel spray area is affected by the mixer venturi and the swirl sense, (4) the symmetry of the fuel presentation is affected by the interaction of the swirler angles, (5) Lean Blow Out (LBO) is not affected by the parameters selected, and (6) the parameters affecting fuel distribution and combustion stability differ, indicating that the combustion performance is not described entirely by fuel distribution.
Progress on Comparison Study of the Erosion of Conventionally Machined and Macrolaminated Pressure-Swirl Atomizers
Authors: Harvey Rex J.
Published: December 2014

Gas turbine fuel atomization nozzles are subject to internal erosion damage caused by the flow of the liquid fuel and its inevitable contaminants. Nozzles must be sufficiently erosion resistant, or erosion tolerant, to insure acceptable performance throughout their design life. Recently developed macrolamination (ML) technology for construction of pressure-swirl nozzles shows potential performance, cost, and size benefits when compared to conventionally constructed nozzles. The objective of this study is to compare macrolaminated and conventional nozzles under identical accelerated erosive conditions to determine their relative wear characteristics. To date, twelve nozzles have been compared with some being disregarded because of anomalies. It is shown that erosion damage results in increased flow rates. Also, the tendencies shown are for conventional nozzles to erode to narrower spray angles and macrolaminated nozzles to erode to wider spray angles. ML nozzles exhibit some important failure modes that differ from nozzles of conventional design.
Current Status of CGT302 (Progressing to Final Phase)
Authors: Ichikawa Yoshihiro , Tatsumi Tetsuo , Nakashima Takashi , Takehara Isashi , Kobayashi Hirotake
Published: December 2014

In Japan, a 300kW Ceramic Gas Turbine (CGT) Research and Development program was begun in 1988 as a part of “the New Sunshine Project” promoted by the Ministry of International Trade and Industry (MITI). The final target of this program is to achieve 42% thermal efficiency at 1350°C turbine inlet temperature (TIT). Kawasaki Heavy Industries, Ltd. (KHI) has been taking part in this program developing the CGT302 (a regenerative two-shaft CGT) with Kyocera Corporation (KC) and Sumitomo Precision Products Co., Ltd. (SPP). Now the final phase of the Pilot CGT is underway. By the end of the fiscal year 1995, the CGT302 achieved 33.1% thermal efficiency at 1200°C TIT, and remarkably low NOx emissions using a premixed lean combustor equipped with a variable air valve. By January 1997, thermal efficiency was increased to 37.0% at 1282°C and fairly low NOx was recorded at 1250°C. The engine rotational speeds were reduced to avoid foreign object damage (FOD). Accordingly, the compressor, gas generator turbine (GGT), and power turbine (PT) blade airfoils were redesigned. Engine tests have been ongoing to accumulate total engine operating time and thereby confirm measured performance, access durability, and identify needed areas of improvement.
Development of a Low-Emission Combustor for a 100-kW Automotive Ceramic Gas Turbine (IV)
Authors: Sasaki Masafumi , Kumakura Hirotaka , Ichikawa Hiroyuki , Ohkubo Youichiro , Yoshida Yuusaku
Published: December 2014

A low emission combustor, which uses a prevaporization-premixing lean combustion system for the 100-kW automotive ceramic gas turbine (CGT), has been subjected to performance tests. A second combustor prototype (PPL-2). which incorporates improvements intended to overcome a flashback problem observed in an initiel combustor prototype (PPL-1), had been tested. Now combustors with further improvements accomplished to the PPL-2 prototype, is tested.

Test results of the PPL-2 combustor showed that, increasing the air distribution ratio in the lean combustion region to aviod flashback, and by providing a uniform flow layer at the entrance of the combustion region so as to supress flashback, were effective in expanding the stable combustion range by substantially improving the flashback characteristics.

To improve the flashback characteristics further more, we have redesinged the bluffbody and the swirl chamber so as to obtain uniform flow of the mixture, in the prevaporization premixing zone.

Test results shows that the flashback characteristics has been greatly improved, and a wide stable combustion range, needed to operate the 100-kW CGT engine, was obtained.
Facilities for Automotive Gas Turbine Ceramic Components
Authors: Avran Patrick , Leclair Alain , Payen Gérard
Published: December 2014

The first part of this paper describes the test facility to characterize the catalytic combustor. The combustion chamber is a LPP combustor (Lean Premixed Prevaporised), made of preheater, premix duct, catalytic part and after burner. Each component will be validated separately for the required conditions (steady state and transient conditions). All the measurements and data acquisition are described.

The second part deals with the test facility for the hot spin test of the ceramic wheel. The base of the test bench is a modified turbocharger (maximum rotating speed: 125000 r.p.m.). With this configuration it will be possible to test the ceramic radial wheel within the AGATA specifications; in this case the compressor is used like a brake.

The last part is devoted to two ceramic heat exchanger test rigs: the first rig is to evaluate the themomechanical stresses on the samples; the second rig to assess the performance compared to the AGATA specifications and to duplicate the transient and thermal shock conditions. In this program the heat exchanger is fixed.
Calculating the Flowfield Behaviour of High-Speed Multi-Stage Compressors
Authors: Longley John P.
Published: December 2014

This paper describes the development of a computational model for the moderate to long lengthscale flowfield behaviour of high-speed multi-stage compressors. The simulation is a time accurate solution of the fully compressible non-linear equations for fluid flow through an entire compressor. Flow in the non-bladed regions is calculated using a two-dimensional Euler solver whilst the individual blade rows are modelled using multiple one-dimensional flowfields with body forces. The body forces are chosen to give the required steady state blade row performance and a physically based circulation model is used to give the correct non-steady flow dynamics. The capabilities of the simulation are demonstrated in this paper by calculating how the flowfield breakdown of a four stage compressor is affected by operating speed and a range of different inlet flow distortions.
The Use of Cyclic Variations in Strut Stagger to Reduce Coupled Blade-Vane-Strut-Pylon Interaction and System Losses
Authors: Parry A. B. , Bailey R. H.
Published: December 2014

In this paper we extend previous work on fan-vane-pylon interaction to account for an additional row of struts between the vanes and the pylon(s). These struts have two effects: they generate their own potential field in addition to that generated by the pylon(s); and they also act to magnify the pylon generated field. The combined effect of the struts and pylon is to generate a nonuniform potential field which is much greater than that generated by the pylon(s) in isolation — and, indeed, much greater than that obtained by simple superposition of the pylon-alone and strut-alone fields — resulting in increased fan forcing and vane losses. We consider two engine configurations: one with struts positioned ahead of a pylon; and one with the struts integrated with two (unequal) pylons. Predictions are generated in two dimensions by using an inviscid CFD scheme for the struts and pylons, linked to a tandem actuator disc model to represent the fan and the outlet guide vanes (OGVs). The predictions are validated by comparison with some vane leading-edge static pressure measurements taken from a full scale engine. The OGV loss in the distorted flow is predicted by judicious use of OGV loss loops for uniform flow.

The predicted results for the first engine with separate struts and pylon show the magnification effect of the struts, and the increase in sectional losses due to the strut and pylon induced circumferential flow variations. It is shown that (at least) half of the increase in sectional losses can be recovered by cyclically staggering the struts with the strut stagger angles determined from a separate pylon-alone calculation. For the second engine with integrated struts and pylons the predictions show that there are even greater increases in the potential field transmitted through the vanes and in the sectional losses, which are two thirds higher than those for the OGVs in uniform flow. However, the predicted increase in OGV losses is reduced to only a fifth with a particular restaggered-strut design; moreover, the loss in the restaggered strut case is lower than that obtained for the isolated pylons with no integrated struts. The results also show that in determining the appropriate strut restagger angles it is important to take account of the back effect of the fan and OGVs.
Effect of a Mismatch Between the Buttons of Variable Stator Vanes and the Flowpath in a Highly Loaded Transonic Compressor Stage
Authors: Escuret J. F. , Veysseyre Ph. , Villain M. , Savarese S. , Bois G. , Navière H.
Published: December 2014

This paper presents both experimental and numerical results demonstrating the dramatic effect of a particular geometric discontinuity on the flow within a highly-loaded single-stage transonic compressor. This compressor features cantilevered variable-stagger stator vanes (VSV) with buttons at the outer radius partially standing out in the annulus, by a value of about 0.3 mm which amounts to 0.5% of vane height.

The first tests of this compressor revealed a very large corner flow separation at the stator outer radius. This feature could not be reproduced by steady 3D Navier-Stokes computations of the stator flow field with a smooth flowpath. However, using a simple numerical approach to account for the actual geometric discontinuity of the annulus, the computation then showed flow trends similar to that of the experiment. Also, a detailed analysis of the computed flow field indicated that the flow turning (both radial and tangential) due to the button blockage contributed toward strengthening the effect of secondary flows. Subsequently, after the button geometry was corrected to match the flowpath, further tests confirmed a much more satisfactory flow behaviour within the stator vanes leading to a one point improvement in compressor isentropic efficiency.

This study leads to the conclusion that ensuring a smooth flowpath can be critically important for the high stage leadings characteristic of advanced military applications. Moreover, the predictive value of 3D Navier-Stokes computations for the simulation of technological effects, such as VSV buttons / flowpath mismatch, is clearly demonstrated.
The Unsteady Pressure Field Over a Turbine Blade Surface: Visualisation and Interpretation of Experimental Data
Authors: Moss Roger W. , Ainsworth Roger W. , Sheldrake Colin D. , Miller Robert
Published: December 2014

The unsteady static pressure field over a turbine rotor has been measured in the Oxford Rotor Facility using 78 flush-mounted miniature pressure transducers. This extensive surface coverage allows ensemble-averaged data to be displayed as an animated image. At the mid-height plane the fluctuations are well predicted using the UNSFLO 2-D unsteady code: away from mid-height the data shows large fluctuations.

12 transducers mounted on the blade leading edge show the relative total pressure field entering the blade row; these plus area traverse measurements at rotor exit are used to interpret the surface flow features. Rotor-mounted hot wires show large variations in blade incidence during the wake-passing cycle and allow conversion of blade-relative data into the absolute frame. Large pressure fluctuations in the root region may be explained in terms of a loss core associated with the NGV wake.
Predicting Bypass Transition: A Physical Model Versus Empirical Correlations
Authors: Johnson Mark W. , Ercan Ali H.
Published: December 2014

A boundary layer transition model is presented which relates the near wall velocity fluctuations to the formation of turbulent spots. This model is used to determine the turbulent intermittency within a boundary layer integral code. Comparisons are made between the code predictions and established empirical correlations for the adverse pressure gradient transition experiments performed by Gostelow and co-workers. Similarly good accuracy was achieved by both the model and empirical correlation for start of transition. However, empirical correlations were less reliable than the model for predicting end of transition. The model was also able to predict the evolution of the measured intermittency considerably more accurately than the Narasimha empirical correlation. The current modelling approach is thus demonstrated to be more reliable than empirical correlation for the modelling of transitional boundary layers.
Experimental Investigation of a Cooling System Entrance for an Annular Gas Turbine Combustion Chamber
Authors: Lindqvist Lars O. , Nilsson Ulf E. , Hylén Jonas N.
Published: December 2014

A cooling entrance region for a modern annular combustor has been successfully tested. Because of high heat load at the entrance part of the liner, a good design is very important. The design presented here offers ultra-low dilution, robustness and high performance. The cooling system includes convective, film and impingement techniques, which were experimentally investigated in a plastic (perspex) model of a full scale 60° sector of a simplified combustor design. The importance of a high performance entrance is obvious. It generates low pressure drop, better combustion (circumferential even flow for the liner cooling) and it gives lower flame temperature (maximizes the air in the flame). Guidelines for the design of such an entrance are presented in this paper.
Navier-Stokes Analysis of Unsteady Transonic Flows Through Gas Turbine Cascades With and Without Coolant Ejection
Authors: Tanuma T. , Shibukawa N. , Yamamoto S.
Published: December 2014

An implicit time-marching higher-order accurate finite-difference method for solving the two-dimensional compressible Navier-Stokes equations was applied to the numerical analyses of steady and unsteady, subsonic and transonic viscous flows through gas turbine cascades with trailing edge coolant ejection. Annular cascade tests were carried out to verify the accuracy of the present analysis. The unsteady aerodynamic mechanisms associated with the interaction between the trailing edge vortices and shock waves and the effect of coolant ejection were evaluated with the present analysis.
Development of a High Pressure Ratio Centrifugal Compressor for 300kW-Class Ceramic Gas Turbine
Authors: Sakai T. , Tohbe Y. , Fujii T. , Tatsumi T.
Published: December 2014

Research and development of ceramic gas turbines (CGT), which is promoted by the Japanese Ministry of International Trade and Industry (MITI), was started in 1988. The target of the CGT project is development of a 300kW-class ceramic gas turbine with a 42 % thermal efficiency and a turbine inlet temperature (TIT) of 1350°C. Two types of CGT engines are developed in this project. One of the CGT engines, which is called CGT302, is a recuperated two-shaft gas turbine with a compressor, a gas-generator turbine, and a power turbine for cogeneration. In this paper, we describe the research and development of a compressor for the CGT302.

Specification of this compressor is 0.89 kg/sec air flow rate and 8:1 pressure ratio. The intermediary target efficiency is 78% and the final target efficiency is 82%, which is the highest level in email centrifugal compressors like this one.

We measured impeller inlet and exit flow distribution using three-hole yaw probes which were traversed from the shroud to the hub. Based on the measurement of the impeller exit flow, diffusers with a leading edge angle distribution adjusted to the inflow angle were designed and manufactured. Using this diffuser, we were able to attain a high efficiency (8:1 pressure ratio and 78% adiabatic efficiency).
Experimental and Numerical Analysis of Compressor Inlet Volutes
Authors: Michelassi V. , Giachi M.
Published: December 2014

A typical compressor inlet volute is studied by using both experimental and numerical approaches. The highly distorted and complex flow pattern is measured in two typical configurations. Measurements include velocity, flow angle, Mach number and losses. The same geometries are analyzed by using a computer code which solves the three-dimensional Navier-Stokes equations. Turbulence effects are modeled by a two-equation turbulence model. The set of measurements shows the flow distortion induced by the volute, and also highlights how this distortion can be controlled or largely reduced by small modifications to the geometry. The computational results indicate an overall good agreement with the measurements and allow reproducing the changes in the pattern induced by the changes in volute geometry. Both the measurements and computations prove the importance of the optimal design of this component which controls the uniformity of the flow approaching the compressor impeller.
Experimental and Numerical Investigation of Boundary-Layer and Wake Development in a Transonic Turbine Cascade
Authors: Michelassi V. , Rodi W. , Gieß P.-A.
Published: December 2014

The flow in a transonic turbine rotor cascade is investigated by both experimental and numerical methods. Measurements include pressure profiles on the blade, total pressure profiles in the blade vane, boundary-layer and wake profiles. Computations are performed by two different solvers with different turbulence models and three different transition models. Results indicate that the introduction of transition models is necessary to have a realistic description of the flow field. Transition is shown to affect also the blade pressure distribution and shock strength mostly on the pressure side boundary layer. Experiments indicate the presence of trailing edge vortex shedding which is not captured by the steady computations. The transition models seem adequate for predicting the shock-boundary layer interaction which induces a small flow separation on the suction side.
A Unique Application of Gas Turbine Engines in a High Speed Marine Vessel
Authors: Higgins Timothy M. , Freuler Richard J. , Blount Donald L. , Thames Janna M.
Published: December 2014

A high speed marine vessel, powered by three LM1600 gas turbine engines, is being converted from a high speed racing vessel to a luxury yacht. The vessel’s geometry is being modified to include a centerline walkway to provide passage to the aft deck.

A scale model of the vessel’s air intake system was tested to determine if the modified design complied with performance specifications determined by the engine manufacturers. It was found that the total pressure loss and distortion of the engine inlet air was within performance limits. However, the swirl angles of the inlet air for the center engine exceeded limits locally.

System modifications were devised and tested to improve the quality of intake air. The modifications decreased swirl angle magnitudes to generally within engine manufacturer’s specifications. Additionally, the expansion of spaces devoted to the other ship systems did not significantly impair the aerodynamic performance of the air intake systems.
Thermal Spray Manufacturing Issues in Coating IGT Hot Section Components
Authors: Sahoo P. , Carr T. , Martin R. , Dinh F.
Published: December 2014

The desire to improve the performance and efficiency of gas turbine engines has led to higher operating temperatures in the turbine sections of the engine. Present materials and materials under development for hot section turbine blades and vanes are not inherently resistant to hot corrosion, and therefore require protective coatings. In the past two decades this has led to increased use of thermally sprayed MCrAlY coatings, both as stand-alone overlay and as a bond coat for thermal barrier coatings.

This paper reviews the issues involved in thermally sprayed MCrAlY and TB coatings onto hot section blades and vanes of industrial gas turbines. The generation of a specification for coating acceptance and its practical implications are discussed. The issues in applying such coatings will be discussed, along with references to manufacturing issues on the shop floor. The difficulties inherent in applying a line-of-sight coating to complex geometric shapes will be discussed, with particular reference to robotics spraying. The utility of using a design-of-experiment approach to satisfy the user will be reviewed. The testing, evaluation, and performance characteristics of typical coatings are discussed.
Heat Transfer-Friction Characteristic Comparison in Rectangular Channel Arrays of Attached, Detached, and Alternate Attached-Detached Ribs on Two Opposite Walls
Authors: Hwang Jenn-Jiang
Published: December 2014

Experiments are conducted to study the effect of three types of rib-arrays, namely composite, fully-attached, and fully-detached ribs, on friction factors and center-line heat transfer coefficients in rectangular channels. Two opposite walls are roughened by alternate attached and detached in-line rib-arrays for the composite ribs. The Reynolds number (Re) based on channel hydraulic diameter ranges from 12,000 to 70,000; whereas the rib pitch-to-height ratio varies from 10 to 30. The rib-to-channel height ratio (or rib height-to-channel hydraulic diameter ratio), and the ratio of the rib clearance to height are fixed at h/2B = 0.2 (h/De = 0.125), and c/h = 0.5, respectively, with a channel aspect ratio (W/B) of 4.0. It takes a longer distance from the channel inlet to set the local heat transfer coefficient into a periodic constant-value distribution for the composite-ribbed wall due to the more complex turbulent transportation. In the fully developed flows, the composite rib-roughened wall yields the highest heat transfer augmentation, and gives moderate pressure-drop penalty among the three types of ribbed walls. Performance evaluation under the constant pumping-power constraint reveals that the composite-ribbed channel performs best of the three ribbed arrangements. Semi-empirical correlations for friction and heat transfer in composite-ribbed channels are developed to account for rib spacing and Reynolds number for the design of gas turbine blade cooling passages.
Process Optimization of an Integrated Combined Cycle — The Impact and Benefit of Sequential Combustion
Authors: Jury Walter , Searles David E.
Published: December 2014

Advanced gas turbine designs require revisiting the optimization process to provide maximum competitiveness of new generating installations. This counts specifically for those designs created for combined cycle applications. Gas turbine performance and its associated exhaust temperature has been increasing at a rapid pace over recent years. The conventional method of selecting a GT based upon price and performance, and then designing a complex bottoming cycle does not provide sufficient solutions for power generation in an open access marketplace. The optimal solution takes into account the interrelation between the GT and WS cycle, leading to a more efficient, simplified and flexible power plant. This analysis shows how different levels of GT exhaust energy lead to different optimum cycle solutions. It shows, as postulated above, that considering the WS cycle demands in gas turbine design leads to a simpler cycle with inherent advantages in efficiency, reliability and flexibility.
Start Up Analysis of a H2-O2 Fired Gas Turbine Cycle
Authors: Funatsu T. , Fukuda M. , Dohzono Y.
Published: December 2014

The new thermodynamic cycle using hydrogen energy is now under investigation by many engineers. The Japanese World Energy Network research program is also hydrogen technology development program. One of the target of the program is to develop the high thermal efficiency power plant without emissions. The H2-O2 fired gas turbine is the key technology of the project and the new RANKINE cycle is suggested as one of the most effective cycle.

The new RANKINE cycle is based on the direct steam expansion cycle and the performance calculation has been examined to find the optimal operating point. For the cycle development, further investigations of the component development, the operational ability, and the cost competitiveness are important. Among these investigations, this paper reports the operational ability, especially the start up performance.

In this analysis, the algorithm and flow line for start up is developed. And the investigation finds that the new RANKINE cycle has the good possibility for the practical use.
Development of High Temperature Gas Sensor Technology
Authors: Hunter Gary W. , Chen Liang-Yu , Neudeck Philip G. , Knight Dak , Liu C. C. , Wu Q. H. , Zhou H. J.
Published: December 2014

The measurement of engine emissions is important for their monitoring and control. However, the ability to measure these emissions in-situ is limited. We are developing a family of high temperature gas sensors which are intended to operate in harsh environments such as those in an engine. The development of these sensors is based on progress in two types of technology: 1) The development of SiC-based semiconductor technology. 2) Improvements in micromachining and microfabricarion technology. These technologies are being used to develop point-contact sensors to measure gases which are important in emission control especially hydrogen, hydrocarbons, nitrogen oxides, and oxygen. The purpose of this paper is to discuss the development of this point-contact sensor technology. The detection of each type of gas involves its own challenges in the fields of materials science and fabrication technology. Of particular importance is sensor sensitivity, selectivity, and stability in long-term, high temperature operation. An overview is presented of each sensor type with an evaluation of its stage of development. It is concluded that this technology has significant potential for use in engine applications but further development is necessary.
Wake Decay: Effect of Freestream Swirl
Authors: Brookfield J. M. , Waitz I. A. , Sell J.
Published: December 2014

A study of the effects of freestream swirl on the decay characteristics of wakes shed from a rotating blade row is presented. The freestream swirl behind the rotor causes the wakes to skew tangentially, stretching the wakes as they are convected from the rotor to the stator. The effect of stretching on wake decay is illustrated using a simplified two-dimensional model. The model is described and the results are compared to 1) measurements from a two-dimensional cascade facility where no stretching or skewing of the wakes occurs, 2) solutions obtained using a three-dimensional, Reynolds-averaged Navier-Stokes solver, and 3) experimental wake measurements taken behind a low hub-to-tip ratio fan.

For typical fan geometries with hub-to-tip ratios of approximately 0.5 and rotor-stator spacings of one to two rotor chord lengths, the wake can be stretched by over 50 percent. The stretching increases the mixing rate which leads to a reduction in the mean wake velocity deficit of approximately thirty percent and a widening of the wake of about fifteen percent. These effects account for much of the difference seen between cascade wake measurements and those taken behind rotating fan blade rows. It is therefore important to include such effects when using cascade data for prediction of fluid mechanic, acoustic, or structural phenomena associated with fan wakes. Finally, the study also suggests a potential for small (< 3 dB) reductions in wake-stator interaction noise through tailoring the fan loading distribution to produce particular span wise wake decay characteristics.
Catalytic Combustor Development for Ultra-Low Emissions Industrial Gas Turbines
Authors: Dutta P. , Yee D. K. , Dalla Betta R. A.
Published: December 2014

The goal of the Advanced Turbine Systems (ATS) program is to develop a high thermal efficiency industrial gas turbine with ultra-low emissions (<10 ppmv NOx, CO and UHC @ 15% O2) over the 50 to 100% load range. Catalytic combustion was chosen as an approach likely to meet ATS emissions goals. A subscale catalytic combustor development program was designed to develop a technical knowledge base for catalyst design (catalyst construction, length), performance (ignition, activity and emissions) and operating limitations (fuel-air turndown and sensitivity to combustor operating variables). A novel catalyst design with preferential catalyst coating to limit substrate temperatures was used in the tests. The catalytic combustor consists of a fuel-air premixer, catalytic reactor and a post-catalyst zone for completion of homogeneous gas phase reactions. In situ measurements of mean fuel concentrations at the exit of the premixer were completed to characterize fuel-air premixing levels. Performance of the catalyst was monitored through global emissions measurements at the exit of the post-catalyst combustor under simulated engine conditions, and measurement of catalyst substrate temperatures. Ultra-low emissions were achieved for relatively uniform fuel-air premixing (<10% peak to peak variation in fuel concentration) with higher inhomogeneities (>10% peak to peak variation) leading to either locally high or low substrate temperatures. Regions with low substrate temperatures led to high CO and UHC emissions. Modeling of post-catalyst homogeneous reactions using a standard stationary, one-dimensional, laminar premixed flame formulation showed good agreement with measurements. In short term tests, the catalysts showed the desired chemical activity and ability for multiple light-off. The subscale combustor development work provided the necessary technical information for full scale catalytic combustion system development for the ATS gas turbine.
A Bernoulli-Euler Stiffness Matrix Approach for Vibrational Analysis of Spinning Linearly Tapered Beams
Authors: Hashemi S. M. , Richard M. J. , Dhatt G.
Published: December 2014

This paper presents a Dynamic Finite Element (DFE) formulation, based on the Dynamic Stiffness Matrix (DSM) approach, for vibrational analysis of spinning beams. The constituent members are considered to be linearly tapered as well as centrifugally stiffened. A non-dimensional formulation is considered, and the frequency dependent trigonometric shape functions are used to find a single frequency dependent element matrix (called DSM) which has both mass and stiffness properties. An adapted bisection method based on a Sturm sequence root counting technique, is used to find the first four out-of-plane flexural natural frequencies of a cantilevered linearly tapered (in height) beam for different non-dimensional rotating speeds. The results have been compared to those found by finite elements method using Hermite beam elements. Much better convergency rates are found by this method when comparing to conventional finite element methods.
An Experimental Investigation of Vibration Localization in Bladed Disks: Part II — Forced Response
Authors: Kruse Marlin J. , Pierre Christophe
Published: December 2014

The results of an experimental investigation on the effects of random blade mistuning on the forced dynamic response of bladed disks are reported. Two experimental specimens are considered: a nominally periodic twelve-bladed disk with equal blade lengths, and the corresponding mistuned bladed disk, which features slightly different blades of random lengths. Both specimens are subject to traveling-wave excitations delivered by piezo-electric actuators. The primary aim of the experiment is to demonstrate the occurrence of an increase in forced response blade amplitudes due to mistuning, and to verify analytical predictions about the magnitude of these increases. In particular, the impact of localized mode shapes, engine order excitation, and disk structural coupling on the sensitivity of forced response amplitudes to blade mistuning is reported. This work reports one of the first systematic experiments carried out to demonstrate and quantify the effect of mistuning on the forced response of bladed disks.
Radial Planar Magnetic Bearing Analysis With Finite Elements Including Rotor Motion and Power Losses
Authors: Rockwell R. D. , Allaire P. E. , Kasarda M. E. F.
Published: December 2014

No literature is currently available which has evaluated finite element power loss models for magnetic bearings and compared the results to experimental results. In this paper a finite element model of the magnetic and electric fields in magnetic bearings, including the motion of the magnetic material in the rotor, is developed. It evaluates the two dimensional magnetic vector potential, magnetic flux density, electric field, eddy current, and power losses in an example magnetic bearing configuration. Results were obtained for both a solid rotor and a laminated rotor. For a solid rotor, both the magnetic flux density and eddy current plots at high rotational speeds are concentrated at the outer edge of the rotor. The ratio of calculated solid to laminated losses is found to be in the range of measured results by other authors. An effective axial conductivity was employed to model a laminated rotor and compared to experimental loss measurements. The correlation between measured and calculated results is quite good for a range of rotor speeds, magnetic flux density, and air gap thickness.
Design and Experiment of Reverse Osmosis Seawater Desalination Unit for Water Supply System of Heat Recovery Boiler of Steam Injection Gas Turbine (STIG) Plant
Authors: Limin Niu , Qun Zheng
Published: December 2014

STIG power plant is a competitive choice for commercial use because of its inherent characteristics and high efficiency. But if it was to be a marine propulsive engine, a fresh water supplying system should be provided for the heat recovery boiler. A two stage experimental reverse osmosis (RO) sea water desalination system which consist of an RO membrane and fine filter and super fine filter etc. is established. The experiments on the system and measurements of the desalination water quality indicate that the RO desalination system is suitable for marine STIG power plant. Some design and experimental problems and experimental results are presented and discussed in this paper.
An Experimental Study of Steam Injection in an Aeroderivative Gas Turbine
Authors: Meyer Jean-Louis , Grienche Guy
Published: December 2014

The injection of steam into a gas turbine allows a reduction in nitrogen oxide (NOx) emissions and an increase in power and efficiency. In this way, and due especially to their lower investment costs, massive steam injection cycles could represent an interesting concept for intermediate-load power plants.

When EDF and TURBOMECA jointly decided to carry out an experimental study of the consequences of steam injection into a gas turbine, two test phases were defined: firstly, a limited steam injection phase to assess the effect of steam on combustion, and secondly, a massive injection phase to assess the behavior and the performance capabilities of the machine. This second phase also aimed at identifying the critical points likely to appear when adapting a heavy-duty gas turbine to massive steam injection. This publication summarizes the main results of these two phases of tests.
Performance Assessment of Steam Injection Gas Turbine With Inlet Air Cooling
Authors: Bartolini Carlo M. , Salvi Danilo
Published: December 2014

The steam generated through the use of waste heat recovered from a steam injection gas turbine generally exceeds the maximum mass of steam which can be injected into steam injection gas turbine. The ratio between the steam and air flowing into the engine is not more than 10–15%, as an increase in the pressure ratio can cause the compressor to stall. Naturally, the surplus steam can be utilized for a variety of alternative applications.

During the warmer months, the ambient temperature increases and results in reduced thermal efficiency and electrical capacity. An inlet air cooling system for the compressor on a steam injection gas turbine would increase the rating and efficiency of power plants which use this type of equipment. In order to improve the performance of steam injection gas turbines, the authors investigated the option of cooling the intake air to the compressor by harnessing the thermal energy not used to produce the maximum quantity of steam that can be injected into the engine. This alternative use of waste energy makes it possible to reach maximum efficiency in terms of waste recovery. This study examined absorption refrigeration technology, which is one of the various systems adopted to increase efficiency and power rating. The system itself consists of a steam injection gas turbine and a heat recovery and absorption unit, while a computer model was utilized to evaluate the off design performance of the system. The input data required for the model were the following: an operating point, the turbine and compressor curves, the heat recovery and chiller specifications. The performance of an Allison 501 KH steam injection gas plant was analyzed by taking into consideration representative ambient temperature and humidity ranges, the optimal location of the chiller in light of all the factors involved, and which of three possible air cooling systems was the most economically suitable. In order to verify the technical feasibility of the hypothetical model, an economic study was performed on the costs for upgrading the existing steam injection gas cogeneration unit. The results indicate that the estimated pay back period for the project would be four years. In light of these findings, there are clear technical advantages to using gas turbine cogeneration with absorption air cooling in terms of investment.
Package Design for a 5500 BHP Aeroderivative Industrial Gas Turbine
Authors: Wenzel Douglas L. , Elmore Jeffrey M.
Published: December 2014

The Cooper-Bessemer Rotating Products group of Cooper Energy Services has designed an all-new industrial gas turbine / compressor package based upon the Allison Engine Company 501-KC5 gas generator with a two-stage industrial power turbine. The latest project management techniques were employed to reduce design cycle time while optimizing total product quality, manufacturability, and reliability. The resulting gas turbine / compressor package is a low-risk, technologically conservative approach, designed to avoid the problems often associated with new product development.
The 6000 shp Class Allison 501-KC5S
Authors: Porter Ronald P. , Lampi Robert A.
Published: December 2014

The 6000 shp class Allison 501-KC5S gas turbine will be introduced to the industrial power generation market in 1997 as a low-risk upgrade of the 501-KC5 engine. The aero-derivative and industrial background of the 501-KC5 engine is discussed along with the 501-KC5S product definition and product description. In addition, near-term horsepower increase plans for a 501-KC7 are outlined.
A Projection of Advancements in Aeroderivative Gas Turbine Technology for the Next Two Decades (With Specific Emphasis on Off-Shore Applications)
Authors: Spector R. B. , Patt R. F.
Published: December 2014

This paper presents the authors’ perspective regarding the growth of gas turbine technology as applied to the industrial market for the next two decades. Although emphasis is placed on off-shore (platform and floating production) applications, the effects of the advance in technology of gas turbines for land based operations is included. Past trends in the advancement of basic gas turbine technology are utilized as the basis to establish this forecast.

An introduction and a description of the Air Bottoming Cycle, the Intercooled Gas Turbine Cycle, and a hybrid gas turbine combining aeroderivative and heavy frame design are also included.
Modularized, Combined LM2500 PE and Plus Package for Power Generation and Mechanical Drive
Authors: Jahr Knuth
Published: December 2014

This paper presents the Kværner design concept for an LM2500 Gas Turbine Package, with combined engine interfaces for both the LM2500 PE and the LM2500 Plus. The paper also presents the Kværner Modularized Auxiliary System concept, where the lube oil module and the fuel modules are located in separate compartments integrated in the turbine skid, protected from soak-back heat and blade-out conditions.