bluuebunny/crossref_metadata_2025 huggingface dataset:
Industrial Design Optimization of Small and Large Size Axial Turbines
Authors: Massardo Aristide , Satta Antonio
Published: March 2015

This paper discusses the possibility of integrating optimization techniques with the design and analysis codes normally utilized in the industrial turbine design works.

The mathematical minimization procedure presented by the Authors in previous works is coupled here with industrial design codes of multistage axial flow turbines (small and large size) utilized by two Italian Companies.

The new industrial optimization procedures allow increases in the efficiency of the turbines to be obtained without the need for modifications in the industrial technology normally utilized to build the machines. The assumed initial turbine design is generally coincident with the conventional — non mathematically optimized — industrial project. In all cases the optimization is achieved by utilizing the blade profiles or “Masters” of the Companies. The results obtained for the optimization of multistage turbines are presented; the advantages concerning the design time and the usefulness of the procedures are discussed.
The Effect of Low Reynolds Number on Straight Compressor Cascades
Authors: Citavy Jan , Jilek Jaromir
Published: March 2015

New low-speed experimental results are presented concerning the effect of very low Reynolds number on the aerodynamic performance of a straight compressor cascade having 65 - 12 10 profile. The effect of Reynolds number on loss coefficient, deviation angle, pressure distribution and AVR within the range of Re = 104 − 105 is demonstrated including 3D effects. Blade surface flow visualisation has also been obtained. The results are compared with previous ones, e. g. by Roberts and are used for constructing a new model of very low Re effect on incompressible flow in a straight compressor cascade.
An Engine Demonstration of Active Surge Control
Authors: Williams J. E. Ffowcs , Graham W. R.
Published: March 2015

Epstein, Ffowcs Williams and Greitzer presented in 1986 arguments that, provided small perturbation stability models were relevant to engine surge and rotating stall, then both could be avoided by active control. The idea was tested and validated on turbocharger compression systems at MIT and Cambridge University. Engine experiments are more difficult, the surge more violent and the signals usually contaminated by noise. This paper describes the early results obtained on a gas turbine engine subjected to the same control strategy. The control system can be switched on when the engine operates in violent surge and smooth operation is restored. This proof that the technique has practical relevance is interesting enough to report in advance of detailed investigations of its scope. This paper reports the experimental details, describes the relevant theoretical model and gives the first positive test results.
Analysis of Experimental Time-Dependent Blade Surface Pressures From an Oscillating Turbine Cascade With the Influence-Coefficient Technique
Authors: Fransson T. H.
Published: March 2015

A two-dimensional section of the last stage of a steam turbine has been investigated experimentally in an annular non-rotating cascade facility as regards to its steady-state and time-dependent aerodynamic characteristics at design and off-design conditions.

The unsteady experimental data obtained with the blades vibrating in the “travelling wave” mode indicate that one of the main reasons for the flutter susceptibility of the cascade lies in the high expansion and following shock wave close to the blade suction surface leading edge and the corresponding high unsteady loading. The decomposition of the experimental data into unsteady aerodynamic influence coefficients validates this conclusion and gives also that another reason for the flutter susceptibility can be found in the fact that the cascade is overlapped for a part of the blade surface where the local flow velocities are close to sonic.

The unsteady aerodynamic influence coefficients show that the instability arises because of the time dependent aerodynamic coupling effects between, essentially, the reference blade and its immediate suction surface and, to a lesser extent, pressure surface neighbors.
Three Dimensional Design of a High Speed Radial-Inflow Turbine by a Novel Design Method
Authors: Zangeneh M.
Published: March 2015

This paper is concerned with the design of a high speed, 5 inch diameter radial-inflow turbine for medium-sized diesel engine turbocharger applications. The turbine was designed by a newly developed fully three dimensional compressible inverse design method, in which the blade shapes are computed for a specified distribution of rV¯θ. The designed blades had non-radial blade filaments and therefore the impeller was carefully analysed for its structural integrity. This was achieved by the iterative use of a three dimensional structural and vibration analysis program and the design method.

The impeller was made by a casting process. The performance of the new impeller was measured and then compared with three other impellers, one conventional and two experimental. The new impeller performed substantially better than all the baseline turbines and showed a 5.5% improvement in the total-to-static efficiency over the conventional turbine, 2.5% of which was attributable to the aerodynamically superior blade shape computed by the three dimensional inverse design method. The improvement in efficiency was not just confined to the design point and an appreciable improvement could be observed at off-design conditions.
Developments Leading to an Axial Flow Compressor for a 25 MW Class High Efficiency Gas Turbine
Authors: Kashiwabara Y. , Katoh Y. , Ishii H. , Hattori T. , Matsuura Y. , Sasada T.
Published: March 2015

In this paper, the development leading to a 17-stage axial flow compressor (pressure ratio 14.7) for the 25 MW class heavy duty gas turbine H-25 is described. In the course of developing the H-25’s compressor, extensive measurements were carried out on models. Experimental results are compared with predicted values. Aerodynamic experiments covered the measurements of unsteady flows such as rotating stall and surge as well as the steady-state performance of the compressor.

Based on the results of these tests, the aerodynamic and mechanical design parameters of the full scale H-25 compressor were finalized on the basis of two model compressors.

Detailed measurements of the first unit of the H-25 gas turbine were carried out. Test results on the compressor are presented and show the achievement of the expected design targets.
Development of a Compact, Light Weight Magnetic Bearing
Authors: Meeks Crawford , Spencer Victor
Published: March 2015

A novel magnetic bearing design was created that uses permanent magnets to generate the primary magnetic field and attraction electromagnets for stabilization and control. This approach uses a geometrically efficient arrangement with a combination of axially flowing permanent magnet field and a circumferentially flowing electromagnetic field. This design was compared analytically with other types of magnetic bearing designs. The design comparison showed the new design to be 50% lighter weight and 50% lower in power consumption than all electromagnetic designs of equivalent performance. A demonstration model of this new approach was built and tested for performance at low shaft speeds. This test model successfully demonstrated the feasibility of this new approach.
Potential Applications of Structural Ceramic Composites in Gas Turbines
Authors: Parks W. P. , Ramey R. R. , Rawlins D. C. , Price J. R. , Van Roode M.
Published: March 2015

A Babcock and Wilcox - Solar Turbines Team has completed a program to assess the potential for structural ceramic composites in turbines for direct coal-fired or coal gasification environments. A review is made of the existing processes in direct coal firing, pressurized fluid bed combustors, and coal gasification combined cycle systems. Material requirements in these areas were also discussed.

The program examined the state-of-the-art in ceramic composite materials. Utilization of ceramic composites in the turbine rotor blades and nozzle vanes would provide the most benefit. A research program designed to introduce ceramic composite components to these turbines was recommended.
A Zonal Approach for Navier-Stokes Computations of Compressible Cascade Flow Fields Using a TVD Finite Volume Method
Authors: Furukawa M. , Yamasaki M. , Inoue M.
Published: March 2015

A new zonal approach for computation of compressible viscous flows in cascades has been developed. The two-dimensional, Reynolds-averaged Navier-Stokes equations are discretized spatially by a cell-centered finite volume formulation. In order to make the present approach robust, the inviscid fluxes at cell interfaces are evaluated using a highly accurate TVD scheme based on the MUSCL-type approach with the Roe’s approximate Riemann solver. The viscous fluxes are determined in a central differencing manner. To simplify the grid generation, a composite zonal grid system is adopted, in which the computational domain is divided into non-overlapping zones, and structured grids are generated independently in each zone. The zonal boundary between two zones is uniquely defined by cell interfaces of one zone, which ensures the uniqueness of the zonal boundary. The communication from one zone to the other is accomplished by numerical fluxes across the zonal boundary. It should be noted that the complete conservation of the numerical fluxes across the zonal boundary can be satisfied by directly evaluating the numerical fluxes using the finite volume method and by ensuring the uniqueness of the zonal boundary. In order to demonstrate the versatility of the present zonal approach, numerical examples are presented for viscous flows through a transonic turbine cascade.
Aero/Aeroderivative Engines: Internal Transducers Offer Potential for Enhanced Condition Monitoring and Vibration Diagnostics
Authors: Werner Malcolm J.
Published: March 2015

Gas turbine aero engines and their ground based derivatives can benefit greatly from the enhanced condition and diagnostic data available from internal vibration transducers. This paper discusses transducer selection, illustrates typical transducer locations and mounting, and describes some of the rotor malfunctions that can be diagnosed from the vibrations data.
Control System Retrofit Completes 10 Years of Gas-Turbine Reliability Enhancements
Authors: Kohlmiller A. A. (Fred) , Piercy W. Brian
Published: March 2015

In 1979, planners at the Arkansas City, Kansas Refinery of Total Petroleum, Inc. investigated expanding the capacity of their fluidized catalyst cracking unit (FCCU). The expansion plan required additional wet gas compression. Also, the volume of air needed for catalyst regeneration would have to be increased. The three existing wet gas compressors were driven by gas-fueled reciprocating engines and the blower, by an electric induction motor. Increasing the capacity of either compressor train required additional horsepower.
Correlated Fuel Property Effects on an F402-RR-406A (Pegasus) Engine Combustor
Authors: Low H. C. , Scott C. J. , Veninger A.
Published: March 2015

An F402-RR-406A (Pegasus) engine has been subjected to extensive sea-level and altitude operation on a wide range of viable emergency fuels. Sea-level main engine starting was successful for all six fuels and windmilling altitude relight tests were equally flawless, even outside the flight envelope. Cold soak sea-level starting was achieved with DFM of viscosities up to 12 centistokes. Clear inter-relationships between combustor metal temperatures, primary zone flame radiation and optically measured exhaust Smoke Numbers demonstrate a common dependence of these parameters upon the indeterminable primary zone soot concentration. Correlations against fuel properties illustrate the dominance of fuel chemistry over physical properties, even with respect to changes in carbon monoxide and unburned hydrocarbon emissions (and hence combustion inefficiency) at low power. The degrees of premixing and prevaporisation within the Rolls-Royce ‘vaporiser’ fuel injector are considered responsible for the diminished significance of physical properties relative to influences upon conventional fuel atomiser behaviour.
Design Considerations in the Development of a 38 MW Gas Turbine Cogeneration Facility
Authors: Hall Andrew D. , Hauhe William E.
Published: March 2015

Cogeneration has proven to be an ideal application for gas turbines, one which subsidiaries of Texaco Producing Inc. and Mission Energy Company have developed in three successful projects to date. The 38 MW Mid-Set project is the latest, having been commissioned for commercial operation in April, 1989.

Several of the Mid-Set design features were developed from past operating experience, while other design features were employed to meet requirements specific to the project. Strict pollution control required the use of water injection, selective catalytic reduction, continuous emissions monitoring and minimal production of waste water. Other design considerations were plant availability, operability and efficiency for the continuous, base load operation of a turbine-generator. The design features and initial operating history of the Mid-Set cogeneration plant are described in this paper.
Free Convection Phenomena in a Ribbed Wall
Authors: Maravegias N. S. , Georgiou D. P. , Papailiou D. D.
Published: March 2015

The present study reports on experimental information regarding the turbulent free convection flow and thermal field structure, along an isothermally heated vertical flat plate with ribs. The hight to distance ratio of the ribs was equal to 0.1.

The obtained experimental data consist of visualization of the flow, as well as detailed mean temperature and turbulent intensity distribution measurements covering the ribbed part of the heated plate. Heat transfer rates and their enhancement, due to the presence of the ribs, have been estimated from the obtained temperature profiles and by using Newton’s cooling law. Comparisons with corresponding measurements in forced convection reported in the literature, are also made.

The described experiments constitute a first approach towards a more detailed investigation regarding the significant free convection currents existing under certain conditions in cooled channels. However, they also reveal some physical aspects of the heat transfer enhancement processes in ribbed surfaces which are believed to be applicable in more general situations and could lead to establishing some design criteria for ribbed surfaces.
FT8A, a New High Performance 25 MW Mechanical Drive Aero Derivative Gas Turbine
Authors: Prario Aldo , Voss Heinrich
Published: March 2015

This paper describes the FT8A, an advanced state of the art, high performance aeroderivative gas turbine under development for variable speed mechanical drive industrial applications. The gas generator, common to the recently developed FT8, is derived from the Pratt & Whitney JT8D-200 series aircraft engine. The power turbine is being designed and developed by Turbo Power and Marine Systems, Inc. (TPM) and MAN Gutehoffnungshütte AG (MAN GHH) under a joint collaboration program. The power turbine features a three stage rotor simply supported between antifriction bearings, advanced aerodynamics, and a low loss exhaust diffuser/collector system. Design features, performance and typical applications of the FT8A are presented.
Offshore Experience of the LM2500 Gas Turbine
Authors: Spector R. B. , Cimino L. S.
Published: March 2015

Approximately 50 years of offshore oil exploration drilling and production have led to refined techniques and equipment selection criteria. Gas turbines have established themselves as the prime source of energy transfer in that sector of the industrial marketplace where space and weight are of major importance. The increased worldwide demand for petroleum has pushed offshore platforms into deeper waters requiring further sophistication in the allocation of space, weight and maintenance resources. The aeroderivative gas turbine meets the above criteria and in addition offers the platform designer high thermal efficiency and system flexibility coupled with ease of maintenance.

This paper presents a summary of experience gained in over 10 years of operation of the General Electric LM2500 gas turbine on platforms in the North Sea. Although all of the circumstances that may be encountered cannot be adequately covered, highlighting the events which occurred in over one million hours of operation presents the potential user with a better understanding of the uniqueness of this type application. The advantages and the reliability of the aeroderivative gas turbine are also discussed.

The LM2500 gas turbine was first introduced into off-shore operation in the Norwegian sector of the North Sea in November 1979, after successful application in gas compression and transmission duty on pipelines and other on shore facilities.
User Experience in Upgrading Early Models of Aero Derived Gas Turbine Pipeline Compressor Units to Current Standards
Authors: Williams Lawrence J. , Pethrick David J.
Published: March 2015

On July 3, 1964 TransCanada PipeLines Limited commissioned the first Rolls-Royce Industrial Avon, in a Cooper Bessemer pipeline compressor set. In 1986, Cooper-Rolls introduced upgraded versions of the Avon (1535E) and power turbine (RT48S). In 1987, TransCanada converted an Avon to 1535E standard at one location and power turbines to RT48S at two other locations. Following one year of acceptable operation, four units were converted to the “Production” standard with both Avon and power turbine upgraded in 1988.

Testing showed the old, modified units to achieve the performance guaranteed for new engines. The condition of the lead Avon 1535E at tear-down after 6000 hours is described, together with a statement on condition after 15000 hours. The four units modified in 1988 were torn down for inspection during the Summer of 1989, and their condition is discussed. Minor operating difficulties are described together with their solutions.

This paper publishes work that was presented without publication at the Toronto conference in June 1989 together with new information which has become available since that time.
Reconstruction of Individual Aerodynamic Performance Stage Characteristics From Multistage Compressor Flange-to-Flange Test Data
Authors: Sapiro Leon
Published: March 2015

An iterative procedure was devised for reconstructing the aerodynamic performance characteristics of each of the stages of a multistage compressor when only the overall performance, determined from flange-to-flange measurements, is available.

The need for this procedure originated during the closed loop testing of a new family of centrifugal compressor stages. To reduce the number of builds and thus expedite the testing time, the compressors were assembled in a series of two-stage configurations. Some of those stages were used in two different builds: in one, they were preceded by the next stage of higher specific speed; and in the other, they were followed by the next stage of smaller specific speed. Uncertainties of the interstage temperature and pressure measurements, which could not be resolved during the closed loop testing, necessitated the creation of a method for reconstructing the characteristics of each of the two stages of each build, which would be based only on the overall measurements taken at the inlet and outlet flanges.

Using this iterative procedure, the individual stage characteristics of the new family of compressor stages were reconstructed and later applied to the performance prediction of many multistage production units of that family. The number of stages ranged from 2 to 8. Factory test results have shown very good agreement with the prediction.
Why an Engine Air Particle Separator (EAPS)?
Authors: Potts Joe Thomas
Published: March 2015

The purpose of this technical paper is to describe how an Engine Air Particle Separator (EAPS) removes contaminant particles before they enter the gas turbine engine. Gas turbine engines perform poorly in air containing sand, volcanic ash, industrial pollutants, etc. Typical dirt related gas turbine malfunctions include:

• Erosion of the engine and air cycle machinery rotating components.

• Clogging and fouling of turbine section.

• Wear of oil wetted components caused by contaminated lubricants.

Contaminated air entering an EAPS is sent through a swirling motion induced by the vortex generator. This swirling motion causes the heavier dirt particles and water droplets to be thrown radially outward by centrifugal force so that they may be scavenged from the engine air intake.

This report will provide test results of helicopters with and without EAPS and describes the steps necessary to design an EAPS for various air vehicles and engines.
Temporally and Spatially Resolved Flow in a Two-Stage Axial Compressor: Part 2 — Computational Assessment
Authors: Gundy-Burlet Karen L. , Rai Man Mohan , Stauter R. Charles , Dring Robert P.
Published: March 2015

Fluid dynamics of turbomachines are complicated because of aerodynamic interactions between rotors and Stators. It is necessary to understand the aerodynamics associated with these interactions in order to design turbomachines that are both light and compact as well as reliable and efficient. The current study uses an unsteady, thin-layer Navier-Stokes zonal approach to investigate the unsteady aerodynamics of a multistage compressor. Relative motion between rotors and stators is made possible by the use of systems of patched and overlaid grids. Results have been computed for a 2½-stage compressor configuration. The numerical data compare well with experimental data for surface pressures and wakes. In addition, the effect of grid refinement on the solution is studied.
A Technique for Measuring Convective Heat Transfer at Rough Surfaces
Authors: Wang Z. , Ireland P. T. , Jones T. V.
Published: March 2015

A new method has been developed for measuring local heat transfer coefficients at rough surfaces. The technique was applied to an idealised section of a large scaled model of a turbine blade cooling passage to assess the effect of surface irregularities which result from the blade manufacturing process. The experimental method is described in full and the results are presented for tests on an isolated pin-fin situated in fully developed channel flow. The effect of the thermal conductivity of the roughness elements is discussed.
Experimental Analysis Data on the Transonic Flow Past a Plane Turbine Cascade
Authors: Šťastný M. , Šafařík P.
Published: March 2015

The paper presents results from aerodynamic tests on a transonic rotor turbine profile cascade, including interferograms of the flow field and aerodynamic data measured downstream from the cascade. The dimensions and aerodynamic data on the cascade are given in detail. Analysis following the experimental data collection was aimed at investigating the sensitivity of transonic flow in the vicinity of the throat and related conditions leading to the compression effect. Further, the development of the flow structure and the cascade parameters over a wide range of exit Mach numbers, as well as incidence angles are shown. The experimental data are compared with results of calculations based on mathematical models.
RAMSCRAM: A Flexible RAMJET/SCRAMJET Engine Simulation Program
Authors: Burkardt Leo A. , Franciscus Leo C.
Published: March 2015

With the resurgence of interest in high supersonic and hypersonic flight there is a need to simulate airbreathing engines which may be used in this flight regime. To meet this requirement the RAMSCRAM code was developed. The code calculates one-dimensional flow properties at each component interface and the overall performance of the engine. It uses equilibrium thermodynamics which accounts for dissociation and allows for any fuel or combination of fuels. The program can simulate ramjet, scramjet, rocket, and ducted rocket engines.
Turbine Tip and Shroud Heat Transfer
Authors: Metzger D. E. , Dunn M. G. , Hah C.
Published: March 2015

Unshrouded blades of axial turbine stages move in close proximity to the stationary outer seal, or shroud, of the turbine housing. The pressure difference between the concave and convex sides of the blade drives a leakage flow through the gap between the moving blade tip and adjacent wall. This clearance leakage flow and accompanying heat-transfer are of interest because of long obvious effects on aerodynamic performance and structural durability, but understanding of its nature and influences has been elusive. Previous studies indicate that the leakage through the gap is mainly a pressure-driven flow whose magnitude is related strongly to the airfoil pressure loading distribution and only weakly, if at all, to the relative motion between blade tip and shroud. A simple flow and heat-transfer model incorporating these features can be used to estimate both tip and shroud heat transfer provided that reasonable estimates of the clearance gap size and clearance leakage flow can be made. The present work uses a numerical computation of the leakage flow to link the model to a specific turbine geometry and operating point for which a unique set of measured local tip and shroud heat fluxes are available. The resulting comparisons between the model estimates and measured heat-transfer are good. The model should thus prove useful in the understanding and interpretation of future measurements, and should additionally prove useful for providing early design estimates of the levels of tip and shroud heat transfer that need to be compensated for by active turbine cooling.
Film Cooling in the Presence of Mainstream Pressure Gradients
Authors: Teekaram A. J. H. , Forth C. J. P. , Jones T. V.
Published: March 2015

Film-cooling in the presence of mainstream pressure gradients typical of gas turbines has been studied experimentally on a flat plate This paper describes, measurements of the spanwise averaged effectiveness and heat transfer coefficient for an inclined slot and a single row of holes in the presence of favourable, zero and adverse pressure gradients. Acceleration parameters of K = 2.62×10−6 and - 0.22 × 10−6 were achieved at the point of injection where the freestream unit Reynolds number was held constant at Re/m = 2.7 × 107. The flow was accelerated to high Mach number and results are analysed using a superposition model of film-cooling which included the effects of viscous energy dissipation. The experimental results show the effects of pressure gradient differ between the geometries and a discussion of these results is included. The unblown turbulent boundary layer with pressure gradient were also studied. Experiments were performed using the Isentropic Light Piston Tunnel, a transient facility which enables conditions representative of those in the engine to be attained.
An Algorithm and Criteria for Compressor Characteristics Real Time Modeling and Approximation
Authors: El-Gammal A. M.
Published: March 2015

Numerous problems are encountered in realizing an adequate real time model for an aircraft engine. The purpose of this article is to propose a systematic approach for modeling and approximating the characteristics of an engine or engine component parts, and to apply this approach to the Viper compressor (VC) characteristics. The proposed approach introduces a set of quantitative model-performance measures. Monitoring these measures makes it possible to take care of the multiple objectives of the model simultaneously and individually, and to attach a guarantee level to the model behavior. A set of (66) models are considered, from which the adequate VC model for real time (RT) simulation purposes is determined.
Combined Cycle Plants With Frame 9F Gas Turbines
Authors: Lugand P. , Parietti C.
Published: March 2015

The new 200 MW-class MS 9001F gas turbines allow combined cycle plants to reach even higher output levels and greater efficiency ratings. Size factor and higher firing temperatures, with a 3-pressure level steam reheat cycle, offer plant efficiencies in excess of 53 %. Heat recovery steam generators have been designed to accommodate catalytic reduction elements limiting flue gas NOx emissions to as low as 10 ppm VD (15 % O2). A range of steam turbine models covers the different possible configurations.

Various arrangements based on the 350 or 650 MW power generation modules can be optimally configured to the requirements of each site.
The Use of Semi-Conductor Sensors for Blade Surface Pressure Measurement in a Model Turbine Stage
Authors: Ainsworth R. W. , Dietz A. J. , Nunn T. A.
Published: March 2015

The development of semi-conductor sensors particularly aimed at gas turbine technology applications is outlined. Methods of manufacture and means of utilising some of the inherent advantages of this type of sensor are discussed.

A novel technique, where miniature sensors are attached directly to the surface where the measurement is required, is described. This technique combines a high surface density of measurement points with a high frequency response capability. Detailed tests of the sensor’s performance have been conducted and results obtained using this technology are presented. The performance tests include frequency response, base strain sensitivity, g sensitivity, and software temperature compensation schemes.

Finally, possible future applications for these techniques in gas turbine technology are outlined.
High Speed Compressor Surge With Application to Active Control
Authors: Cargill A. M. , Freeman C.
Published: March 2015

This paper discusses the mechanics of surge as observed on the high speed axial compressors of modern aero-engines. It argues that the initial stage of the instability consists of a high amplitude blast wave that develops non-linearly from a small scale disturbance and is thus not correctly described by traditional small perturbation stability theories. It follows from this that active control schemes of the global type may be inappropriate, since to be effective, control would have to be applied in a short time and in a very detailed manner, requiring a large number of transducers and actuators. Active control may, though, be effective in controlling the disturbances that grow into the above blast wave and in the control of other phenomena such as rotating stall, given an adequate number of transducers.
Endwall Losses and Flow Unsteadiness in a Turbine Blade Cascade
Authors: Adjlout L. , Dixon S. L.
Published: March 2015

The purpose of this paper is to describe an investigation of the flow within and downstream of a turbine blade cascade of high aspect ratio. A detailed experimental investigation into the changes in the endwall boundary layer in the cascade (100deg camber angle) and total pressure loss downstream of the cascade was carried out. Flow visualisation was used in order to obtain detailed photographs of the flow patterns on the endwall and for exhibiting the trailing edge vortices. Pressure measurements were carried out using a miniature cranked Kiel probe for three planes downstream of the cascade, with two levels of turbulence intensity of the free-stream. Pressure distribution on the blade were measured at three spanwise locations, namely 4%, 12%, and 50% of the full-span from the wall. Hot wire anenometry combined with a spectrum analyser program was used to determine the frequencies of the flow oscillations.

The change in turbulence level of the free stream has a significant influence on all three pressure distributions. The striking difference between two of the pressure distributions is in the aft half of the suction side where the distribution with the lower turbulence intensity has the larger lift. The oil flow visualisation reveals what appears to be two separation lines within the passage and are believed to originate from the horseshoe vortex. The pitchwise-averaged total pressure loss coefficient increases with the distance of the measurement plane downstream of the cascade blades. A substantial part of this loss increase close to the wall is caused by the high rate of shear of the new boundary layer on the endwall.
Aero-Thermal Performance of a Two Dimensional Highly Loaded Transonic Turbine Nozzle Guide Vane: A Test Case for Inviscid and Viscous Flow Computations
Authors: Arts Tony , De Rouvroit Muriel Lambert
Published: March 2015

This contribution deals with an experimental aero-thermal investigation around a highly loaded transonic turbine nozzle guide vane mounted in a linear cascade arrangement. The measurements were performed in the von Karman Institute short duration Isentropic Light Piston Compression Tube facility allowing a correct simulation of Mach and Reynolds numbers as well as of the gas to wall temperature ratio compared to the values currently observed in modern aero engines. The experimental programme consisted of flow periodicity checks by means of wall static pressure measurements and Schlieren flow visualizations, blade velocity distribution measurements by means of static pressure tappings, blade convective heat transfer measurements by means of platinum thin films, downstream loss coefficient and exit flow angle determinations by using a new fast traversing mechanism and freestream turbulence intensity and spectrum measurements. These different measurements were performed for several combinations of the freestream flow parameters looking at the relative effects on the aerodynamic blade performance and blade convective heat transfer of Mach number, Reynolds number and freestream turbulence intensity.
Development of ODS Superalloy Technology in Japan for Turbine Blade Applications
Authors: Mino Kazuaki
Published: March 2015

The strength of ODS superalloys has not been so satisfactory as to attract much attention for application in turbine blades. As one of the advanced material program supported by MITI, cooperative works were undertaken to develop ODS superalloys superior to monocrystalline alloys. Mechanical properties of new ODS alloys developed in Japan were summarized to evaluate their potentials for turbine blade applications. The project tasks included isothermal forging and diffusion bonding studies for blade fabrication.
Fully Loaded Factory Test of the CW251B12 Gas Turbine Engine
Authors: Diakunchak Ihor S.
Published: March 2015

The fully loaded factory test of the CW251B12 45 MW class industrial gas turbine is described in this paper. This gas turbine is the latest uprating of the W251 series of engines. The main objectives of the factory test were the verification of the performance and the mechanical integrity of the new engine model. A brief description of the main features of the engine, the application of the first unit, the test facility, and the engine instrumentation used in the test is included. Details of the engine performance test results, telemetry test data results, and the hot end component metal temperature measurements are provided.
Assessing Diagnostic Techniques for Poblem Identification in Advanced Industrial Gas Turbines
Authors: Lifson Alexander , Smalley Anthony J. , Quentin George H. , Zanyk Joseph P.
Published: March 2015

This paper describes existing, developing, and needed methods for detection, identification, and diagnosis of problems in combustion turbines. The use of combustion turbines for electrical power generation is growing, and advanced models of large industrial turbines are now starting to enter service. In view of the harsh operating conditions and severe service to which these new turbines will be exposed, this paper evaluates sensors and signal analysis methods to detect and diagnose the problems which may surface in operation. Generic problems which have been observed in combustion turbine installations in the recent past are identified, and methods for detecting these problems, quantifying them, and isolating their causes are analyzed.
Gas Turbine Performance Improvement Direct Mixing Evaporative Cooling System American Atlas Cogeneration Facility Rifle, Colorado
Authors: Nolan J. P. , Twombly V. J.
Published: March 2015

This paper discusses the design, installation, operation and performance of a direct mixing evaporative cooling system as an alternate to conventional wetted rigid media systems used for gas turbine power augmentation. The economic return on investment, the ease of installation, and the potential problems as they apply to a typical gas turbine based cogeneration facility are discussed and analyzed. Especially of interest is the low capital cost of this system, approximately one fourth that of a conventional system.
Off-Design Performances of Fully-Fired Combined Cycle Cogeneration
Authors: Gang Fang , Ruixian Cai , Rumou Lin
Published: March 2015

An analysis on off–design performances of fully–fired gas turbine / boiler cogeneration is presented. The complication can be eliminated by using non–dimensional parameters and dimensional analysis in off–design investigation. The suitable dimensionless parameters on boiler side have been derived, which can be easily applied to the correction of cogeneration test on site at the first stage of plant commissioning process if the parameter variations with ambient condition are not supplied by manufacturer. According to the method developed, the off–design performances of a demonstration fully–fired combined cycle cogeneration in China have been analyzed. Two operating choices are investigated thoroughly. From the results obtained, some considerations of part–load performances of such type power system are given.
The Role for Expert Systems in Commercial Gas Turbine Engine Monitoring
Authors: Doel David L.
Published: March 2015

During the past few years, condition monitoring of gas turbine engines has blossomed into an economically viable activity for some of the larger commercial airlines. These gains have been spurred to a significant degree by the development of sophisticated software algorithms for the interpretation of the limited available sensors. Software packages such as GE’s GEM and Rolls Royce’s COMPASS are being employed to realize many of these gains. Neither of these packages makes use of artificial intelligence despite the recent flurry of activity in this area. This paper reviews the recent commercial condition monitoring progress and suggests areas where AI and other advanced techniques could produce substantive gains.
Factors That Affect Rolling Contact Fatigue Life of Ceramics and Rolling Contact Fatigue Life of Ceramic Balls and Rollers
Authors: Nishihara Y. , Nakashima H. , Tsushima N. , Ito S.
Published: March 2015

The rolling contact fatigue life of ceramics for rolling bearings has improved remarkably in recent years, and is now superior to that of bearing steels. This paper describes experiments to investigate the influence of manufacturing process variables on rolling contact fatigue life and compares the rolling contact fatigue life of current improved ceramics with bearing steels.
MS 9001F: A New Advanced Technology 50 Hz Gas Turbine
Authors: Brandt D. E. , Colas M.
Published: March 2015

Following a thorough market analysis, the MS 9001F heavy duty gas turbine has been designed using aerodynamic scaling based on the 60 Hz MS 7001F.

Effort put into the design has been shared by the engineering departments of ALSTHOM and GE.

This paper discusses the market surveys for large heavy duty gas turbines as well as the basis of design for the MS 9001F, which has been derived from the MS 7001F. Specifically discussed are the role of scaling, the design characteristics of the MS 7001F and the MS 9001F, the results of 7001F prototype testing, the test plan for the MS 9001F, plant lay out possibilities and ratings.

The MS 9001F gas turbine uses advanced aircraft engine technology in its design, with a rating based on a firing temperature of 1260°C (2300°F), which is 156°C (280°F) higher and with compressor inlet flow 50% greater than its predecessor, the MS 9001E.
Future of Combined-Cycle Plants in Belgium
Authors: Mathieu Philippe
Published: March 2015

In this paper we investigate the possible penetration of combined-cycle plants in the Belgian electricity generation system after the Belgian Government has not considered as appropriate the construction of a next nuclear plant at the present time. First the characteristic features of the Belgian production capabilities are given. The share of gas turbines, turbojets and already existing combined-cycle plants and their operation modes are emphasized. Then, alternative options to nuclear energy are presented, i.e. repowering of existing plants and construction of new combined-cycle plants. The potentialities of gas turbines and CC plants as well as their future in Belgium are investigated.

Finally we discuss the equipment plan for the Belgian generation system proposed by the management committee of the electrical plant operators.

From the results of our research about repowering, gas turbines and new CC plants, we derive recommendations for the future production means in Belgium.
Influence of Cascade Parameters on the Deposition of Small Particles
Authors: Kladas D. D. , Georgiou D. P.
Published: March 2015

Present day turbine cascades are being optimized, usually, for minimum total pressure losses. Gas Turbines, however, operating in a dirty environment or using dirty fuels need cascades that minimize the erosion and the corrosion implications of the hostile environment of the flue gasses. The present study employs the parametric cascade optimization method by Mcdonald to study the influence of a number of parameters on the deposition velocity of various particles, typical of those in a PFBC Gas Turbine. The calculation code employs the TSONIC and the STAN5 codes plus the method of Stewart for the aerodynamic losses and two property chosen models for the eddy diffusion one. The results indicate that control is possible only for particles with a diameter of less than 10.0 μm and this usually at the expense of an increase in the aerodynamic losses.
Determination of Fracture Origin in Ceramic Radial Rotor by Taking Photographs at Failure From Two or Three Directions
Authors: Kamiya Nobuo , Asai Mitsuru , Bessho Akinobu , Wada Shigetaka
Published: March 2015

A technique involving taking moment photographs from two or three directions at failure of ceramic radial rotor was developed to determine the position of fracture origin of the radial rotor revolving at a high speed.

The position of the fracture origin of the silicon nitride radial rotor, 60mm in outer diameter and fabricated by injection molding, was demonstrated to be the fillet at the base of the shaft subjected to high stress. Furthermore, the dependence of cracking modes of rotors on the position of fracture origin was demonstrated using ceramic rotors with artificial flaws.
Development of Ceramic Engine Parts for Heat Insulated Engine
Authors: Kawamura Hideo
Published: March 2015

In order to develop a ceramics engine with heat insulated combustion chambers, the strength of engine parts made of ceramics materials, design methods of the parts and triborogical features were studied for producing ceramics engine. In order to use the ceramics materials mainly Si3N4 with a suitable strength and fracture toughness, the correlation of strength and pore or flaw size or microstructures were investigated.

On the other hand, designing methods were studied by using the calculation results of F. E. M on the practical engine and the strength of ceramics. Also, we investigated the characteristics of triborogical factors on the test pieces made of ceramics materials.

In the result, we have achieved to produce the ceramics engine with a satisfactory durability and a lower friction through very severe tests.
The Effect of Ambient Pressure on the Spray Characteristics of a Twin-Fluid Atomizer
Authors: Drennan S. A. , Sowa W. A. , Samuelsen G. S.
Published: March 2015

A combined simplex/air-assist atomizer with swirl is characterized in an isothermal high pressure spray characterization chamber, with optical access, under various ambient pressures. A single-component, phase Doppler laser interferometer is used to obtain spatially resolved droplet size and velocity information. Data are obtained at atmospheric pressure as well as 3 and 6 atmospheres for conditions of constant fuel and atomizing air flow rates. Two different nozzle air flow rates and, hence, two different air-to-liquid ratios are considered. Increasing ambient pressure decreases the air-to-liquid momentum ratio and thereby decreases droplet mean axial velocity and increases the droplet size. The response of a spray to increasing ambient pressure is sensitive to the parameters which are held constant while increasing ambient pressure. The appropriate scaling parameters for the extrapolation of atmospheric testing data to high ambient pressures are likely geometry specific, and will require data of the type reported here.
Analysis of Silicon Germanium Standards for the Quantification of SiGe Microelectronic Devices Using AES
Authors: Mallinson Christopher F. , Littlejohns Callum G. , Gardes Frederic Y. , Castle James E. , Watts John F.
Published: March 2015

Four samples of well-defined silicon-germanium alloys were used as standards for calibration purposes to allow accurate quantification of silicon-germanium-on-insulator (SGOI) microelectronic devices using Auger electron spectroscopy. Narrow Si KLL and the Ge LMM, high resolution Si KL2,3L2,3 and Ge L3M4,5M4,5 together with survey spectra were collected and are presented from each sample. A matrix effect was observed for silicon in germanium and calculated as 0.85 and 0.95 for the Ge77.5Si22.5 and Ge52.4Si47.6 alloys respectively.
Sound absorption of a rib-stiffened plate covered by anechoic coatings
Authors: Fu Xinyi , Jin Zhongkun , Yin Yao , Liu Bilong
Published: March 2015

Underwater vehicles are often equipped with anechoic coatings to absorb the sound waves of active sonar and attenuate the noise emitted from the vessels. Rubber layers with periodically distributed air cavities are widely used as anechoic coatings. In this paper, the sound absorption of anechoic coatings embedded with doubly periodic cavities and backed with periodically rib-stiffened plates is investigated using a finite element method (FEM) with Bloch-periodic boundary conditions. Numerical results given by the FEM are compared with those of a simplified transfer impedance approach to explain the shifting of the main absorption peak. Further a simplified FEM approach, which reduces calculation time significantly and maintains the reasonable accuracy, is proposed for a comparison. The results indicate that the plate and the ribs can have significant impacts on the absorption performance of anechoic coatings, especially at low frequencies.
Outside the coding genome, mammalian microRNAs confer structural and functional complexity
Authors: Olive Virginie , Minella Alex C. , He Lin
Published: March 2015

MicroRNAs add functional complexity to mammalian genomes.
Dysregulation of microRNA biogenesis and gene silencing in cancer
Authors: Hata Akiko , Lieberman Judy
Published: March 2015

Altered microRNA production in cancer promotes cell proliferation, migration, survival, and adaptation to new environments.
Interleukin-10–producing CD5
+
B cells inhibit mast cells during immunoglobulin E–mediated allergic responses
Authors: Kim Hyuk Soon , Kim A-Ram , Kim Do Kyun , Kim Hyun Woo , Park Young Hwan , Jang Geun Hyo , Kim Bokyung , Park Yeong Min , You Jueng Soo , Kim Hyung Sik , Beaven Michael A. , Kim Young Mi , Choi Wahn Soo
Published: March 2015

When specialized B cells come into contact with mast cells, the B cells produce a cytokine that inhibits the mast cells, thereby blunting allergic responses.
EGF induces microRNAs that target suppressors of cell migration: miR-15b targets
MTSS1
in breast cancer
Authors: Kedmi Merav , Ben-Chetrit Nir , Körner Cindy , Mancini Maicol , Ben-Moshe Noa Bossel , Lauriola Mattia , Lavi Sara , Biagioni Francesca , Carvalho Silvia , Cohen-Dvashi Hadas , Schmitt Fernando , Wiemann Stefan , Blandino Giovanni , Yarden Yosef
Published: March 2015

Growth factor–induced metastasis involves microRNA-mediated repression of a tumor suppressor.