bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Variational Finite Element Method for Solving the Blade-to-Blade Flow in Centrifugal Compressor’s Cascades With Splitter Blades on an Arbitrary Streamsheet of Revolution and a Mathematical Treatment to the Region Behind Cascades
Authors: Yulin Chen , Kangmin Chen , Dangfang Zhang 
Published: April 2015

A variational finite element method for solving the blade-to-blade flow in centrifugal compressor’s cascades with splitter blades on an arbitrary streamsheet of revolution is suggested in this paper. At first, the variational principles Ref.(1) is modified, then the variational principle after modification is discretized by eight node isoparametric finite elements to carry out the system of nonlinear algebraic equations for solving the velocity potential function. Finally, the flow field which agrees with Kutta condition and has an region behind the cascade of enough length has been worked out.
In this paper, it has been discovered that when the region behind cascade L3 spreads too long the system of equations might become unsolvable as a suitable exit angle β2 can't be found. The linear relation between the velocity defference of the two side of the trailing edge and the exit angle β2 has been found, it shows the range of linear variation of β2 decreases with the increasing of the length of the region behind cascades, in addition, the linear variational relation between tan⁡β2 and L3 has also been obtained.
The iterative computational method for the flow field with different length L3 is used to get the solution of flow field satisfying Kutta condition and with enough length L3.
Design and Development of the PGT 10 Heavy-Duty Advanced Gas Turbine
Authors: Benvenuti E. , Gusso R. 
Published: April 2015

The PGT 10, a heavy-duty two shaft industrial gas turbine in the 10,000 to 14,000 HP (7,500 to 10,500 kW) nominal power range has been designed; the prototype unit is in construction, with testing scheduled in 1986.
The main distinctive design features are a high pressure ratio and the capability of regenerative cycle operation, coupled with an uncommon combination of adjustable compressor stator vanes and power turbine nozzles, providing very high flexibility in control of cycle parameters. In association with state of art firing temperatures, simple cycle thermal efficiencies up to 34% can be anticipated, while a 36% efficiency level over the whole power range is possible with coupling to a regenerator.
Reliability and long life of hot parts were pursued through extensive reference to successful heavy-duty turbine experience and careful trade-off between aerodynamic design and implementation of nozzle and blade cooling devices; extensive laboratory model tests have been performed to properly check and calibrate hot part cooling flows and distributions prior to full prototype testing.
Higher Availability and Efficiency Using On-Line Real Time Diagnostic and Prognostic Systems on Gas Turbine Compressor Trains
Authors: Boyce M. P. , Lam Tom K. 
Published: April 2015

High Speed Turbomachinery Systems are getting more complex as they require wide operating ranges as well as higher discharge pressures. Both these facts lead to systems being designed to their most critical stage in both mechanical and aerothermal states. Additionally, the high cost of fuel and downtime requires that the machinery have some type of data acquisition which can diagnose and prognosticate possible consequences before they occur and run the system as efficiently as possible. This paper deals with such a system and enables these goals to be achieved.
Aspects relating to a system developed to monitor three gas turbine reinjection compressor trains on an offshore platform is discussed. Two different types of on-line realtime systems are discussed. One is a highly sophisticated multifunction condition monitoring system. Such a system has been developed for offshore platforms to monitor gas turbine compressor trains. The other on-line system is a dedicated surge control system.
Investigation of the Transient Response of a Dual-Rotor System With Intershaft Squeeze Film Damper
Authors: Li Qihan , Hamilton James F. 
Published: April 2015

A method is presented for calculating the dynamics of a dual-rotor gas turbine engine equipped with a flexible intershaft squeeze-film damper. The method is based on the functional expansion component synthesis method.
The transient response of the rotor due to a suddenly applied unbalance in the high-pressure turbine under different steady-speed operations is calculated. The damping effects of the intershaft damper and stability of the rotor system are investigated.
Investigation of the Steady-State Response of a Dual-Rotor System With Inter-Shaft Squeeze Film Damper
Authors: Li Qihan , Yan Litang , Hamilton James F. 
Published: April 2015

This paper presents an analysis of the steady-state unbalance response of a dual-rotor gas turbine engine with a flexible intershaft squeeze film damper using a simplified transfer matrix method. The simplified transfer matrix method is convenient for the evaluation of the critical speed and response of the rotor system with various supports, shaft coupling, intershaft bearing, etc.
The steady-state unbalance response of the rotor system is calculated for different shaft rotation speeds. The damping effects of an intershaft squeeze film damper with different radial clearances under various levels of rotor unbalance are investigated.
Vibration Characteristics of 50 Hz, 120 MW Gas Turbine
Authors: Okubo Atsuo , Mori Yoshitaka , Nadai Yoshikazu , Kanki Hiroshi 
Published: April 2015

This paper describes the vibration analysis technology of MW-701D Gas Turbine which was developed by Mitsubishi Heavy Industries, Ltd. for 50 Hz utilities.
MW-701D is the highest performance gas turbine available with a firing temperature of 1,154°C for base load operation. It is employed by the 1,090 MW combined cycle plant, one of the largest of its kind in the world, and the plant began commercial operation at half of the total capacity of 1,090 MW in December, 1984. The plant was designed to supply base load electric power generation by burning imported liquefied natural gas (LNG) fuel. This paper describes the general description of the combined cycle plant and the vibration characteristics of MW-701D Gas Turbine.
The Finite Element Stress Analysis for Solid-Shell Combined Parts in Aeroengines
Authors: Zeyong Yin , Peizheng Ren , Jing Yin 
Published: April 2015

In the finite element stress analysis of solid-shell combined parts in aeroengines, isoparametric solid elements, superparametric shell elements, solid-shell transition elements and a series of coarse-fine mesh transition elements have been specially established and used so that the parts of complex shape can be modeled realistically, and the amount of input data and computing time can be reduced.
In this paper, the basic method used, the formulation of the various elements and the solving of the equilibrium equations are presented, and the function and the structure of the general purpose program CACS are described.
The Numerical Experiments of the Unsteady Aerodynamic for the High-Turning Oscillating Cascades
Authors: Yi Chen Zuo , Sheng Duan Qiu , Zhong Duan Shi 
Published: April 2015

An “oscillating mean-streamline method” is presented in this paper. It is used to calculate the unsteady aerodynamic force on the oscillating high-turning cascade. An oscillating streamline physical model is discussed, basic relations of the oscillating streamline are derived, the calculations of several examples are given and are compared with corresponding experimental data.
The validity and reliability of this method is also analysed.
The Computer Aided Design and Experiment of the Transonic Turbine Cascade
Authors: Zhao Yuqi , Zhan Tingxiong , Xiao Hongen , Zheng Jianhui 
Published: April 2015

This paper presents a method for the computer aided design of the transonic turbine blade profile shaping and aero thermodynamic analysis.
A new technique of “Computational Geometry” was developed for blade flow path shaping. An improved method of “Streamline Curvature” for cascade analysis is used for blade-to-blade stream surface analysis.
Using above method, a high-loaded turbine cascade with anti-convex suction surface near the trailing edge has been successfully designed, and appreciable supersonic performance was achieved through wind tunnel test.
This method has been included in our “Turbine Blade Computer Aided Design System (GTCAD)” as one of the core modules.
Measurements of Mass Transfer Coefficient and Effectiveness in the Recovery Region of a Film-Cooled Surface
Authors: Webster W. P. , Yavuzkurt S. 
Published: April 2015

Mass transfer coefficients and the film cooling effectiveness are measured downstream of a single row of holes inclined 30 degrees with the surface and inline with the main turbulent boundary layer flow. The mass transfer coefficients (based on the difference between the free stream and the surface concentrations) are measured using a naphthalene sublimation technique. The effectiveness is determined through the injection of a trace gas into the secondary (cooling jets) flow and measuring its concentration at the impermeable wall. Experiments are carried out in a subsonic, zero pressure gradient turbulent boundary layer, under isothermal conditions with three blowing ratios (Uj/U∞): 0.4, 0.8, and 1.2. The data is collected in a region 7 to 80 jet diameters downstream of the injection location.
From the data on mass transfer coefficients and effectiveness obtained under the same flow conditions a general mass transfer equation is derived. This paper presents extensive data and discussions; and is believed to be one of the few studies in which both of these variables are measured on the same surface and in a large area in the recovery region.
The Influences of Off-Design Incidence Angle and Discrete Hole Shapes on Film Cooling Effectiveness
Authors: Ko Shao-Yen , Liu Deng-Ying , Jia Jian-Guo , Tsou Fu-Kang 
Published: April 2015

Detailed tests have been conducted in the cascade heat transfer wind tunnel in order to investigate film cooling effectiveness of single and double-row discrete holes on the leading edge of the pressure surface of a turbine blade. Mass transfer analogy has been used in this experiment. Carbon dioxide was added to the cooling air. The concentration distribution of the carbon dioxide downstream of the cooling film was measured by chromatograph.
Two sets of testing blades with discrete holes of different shapes were used. The first set had round holes with diameter of 1.5 mm, and the ejection angle was 70°. The second set had rectangular holes with width of 1.0 mm and whose ratio of length to width was 5, the ejection angle being 90°. The holes between rows were arranged in staggered pattern.
It was found that the incidence angle has strong influence on film cooling of turbine blades. The film cooling effectiveness near the ejection hole on the pressure surface (concave surface) is higher than that on a flat plate and on a suction surface (convex surface). Over a wide range of blowing ratio M, the film cooling effectiveness of rectangular hole is much higher than round holes.
The Allison 570/571 Gas Turbine for Patrol Boat Power
Authors: Roberts John E. 
Published: April 2015

This paper discusses the use of 570/571-KF engine in patrol boat propulsion applications. The text is composed of two basic sections — 1. The Engine, and 2. The Applications:
The engine section includes a brief review of the background and development of this free turbine engine, as well as a description of the main components and design features. The performance characteristics and fuel consumption rates are discussed relative to patrol missions.
In the applications section a comparison is made of the current 570 installations (both civil and military), along with a survey of the planned applications. Finally a review of proposed uses of these engines in other naval vessels is included to show the adaptability of this size engine in FPB and PB missions, and demonstrate the feasibility of retrofitting other turbine or diesel powered patrol boats with 570/571-KF engines.
The conclusion is drawn that for patrol boats with conventional or modified hull forms, the Allison 570/571 engines are well suited due to their excellent performance and power density ratios.
The Performance of a Reverse Flow Combustor Using JP 10 Fuel
Authors: Winter J. , Maden K. H. 
Published: April 2015

The test rig performance of a fan spray fuel injection reverse flow combustor for a 500 shp engine using JP 10 fuel is compared with that using aviation kerosene, (Avtur). JP 10 fuel is a pure hydrocarbon with a hydrogen content of 11.8% compared with some 13.8% for aviation kerosene.
The comparative performance data reported include fuel injector atomisation characteristics, exhaust combustion efficiencies and emmissions, exhaust temperature distributions, flame tube metal temperatures and simulated pressure altitude relight and combustion stability over a range of conditions up to a simulated altitude of 6,1 km.
A Model for Bluff Body Flame Stabilization
Authors: De Champlain J. A. , Bardon M. F. 
Published: April 2015

Previous work on bluff body stabilization mechanisms is reviewed, and existing models are categorized in tabular form, showing the underlying assumptions and resulting equations. Lacunae in existing models are discussed, particularly their reliance on characteristics such as laminar flame speed which is difficult to predict for the conditions encountered in turbojet afterburners.
A model for bluff body flame stabilization is proposed based on the stirred reactor approach. In addition to the effect of temperature, pressure and geometry, it includes chemical effects such as vitiation and fuel-air equivalence ratio. Blow off velocities predicted by the model are compared to experimental data for various conditions.
A Study on NOx Emissions From Gas Turbine Combustor
Authors: Sasaki Masafumi , Itoh Takane 
Published: April 2015

A conventional diffusion-flame combustor and a two-stage combustor, both made of ceremics, were tested using various fuels.
In both combustors, CO, HC and smoke emission were extremely low even when using heavy-B fuel because of higher than normal inlet temperature of up to 1200 K; however, a great amount of NOx emission was observed in the conventional diffusion-flame combustor. When low-nitrogen fuels such as kerosene were used, a successful reduction of NOx was achieved by providing lean combustion in an improved diffusion-flame combustor. For high-nirogen fuels, the conversion fraction of fuel nitrogen to NOx could be minimized by keeping the equivalence ratio slightly rich in the first stage of the two-stage combustor.
Production and Development of Secondary Flows and Losses Within Two Types of Straight Turbine Cascades: Part 2 — A Rotor Case
Authors: Yamamoto A. 
Published: April 2015

Part 1 of this paper[1] presented the detailed mechanism of secondary flows and the associated losses occurring within a straight stator cascade with a relatively low turning angle of about 65°. Significant contribution of secondary flows on the loss production process was shown only near the blade suction surface downstream from the cascade throat (Z/Cax=0.74) in which region flows decelerated due to adverse pressure gradient.
In the second part, the same experimental analysis was applied to a straight rotor cascade with a much larger turning-angle of 102°. Flow surveys were made at twelve traverse planes located throughout the rotor cascade. The larger turning results in a similar but much stronger contribution of the secondary flows on the loss developing mechanism. Evolution of overall loss starts quite early within the cascade, and the rate of the loss growth is much larger in the rotor case than in the stator case.
Analytical Solution for the Matrix- and Fluid-Temperature Distribution in Rotating Regenerators
Authors: Niggemann Michael 
Published: April 2015

In a rotary regenerator, the matrix- and fluid-temperature distribution in space and time on either side (hot and cold) of the matrix is governed by a coupled system of partial differential equations (PDEs). These are derived from a heat balance under the usual assumption that heat transfer between fluid and matrix is by convection only.
The system of PDEs for the temperature distribution has generally been believed to be not analytically solvable in the case of a regenerator with finite heat transfer coefficients.
In this paper, the analytical solution is given by means of a Laplace transform combined with linear operator theory.
Furthermore, an iterative numerical scheme for calculating the regenerator performance under steady state and transient conditions, based on the analytical representation, is given.
Coal-Fired Gas Turbines for Marine Propulsion Applications
Authors: Kuo Simion C. 
Published: April 2015

This paper discusses the prospects of using coal as the primary source of energy to power gas turbines for marine propulsion applications. The problems associated with burning coal for generating power are reviewed in terms of their inherent limitations, environmental effects, compatibility with turbomachinery combusters, and economic considerations. Various forms of coal-based heat sources and their applicable combuster system configurations are identified. Integration of these fuel/combustor combinations with different gas turbine cycles yields a number of possible coal-fired gas turbine systems. A comparison of these candidate systems with marine propulsion system requirements resulted in the selection of a COGAS system burning coal-oil slurry. Candidate COGAS system configurations are presented, and the overall propulsion engine performance is defined.
A baseline coal-oil fired marine COGAS propulsion system was selected, and its performance characteristics were estimated, taking into account the exhaust gas flow effect on the waste-heat steam generator. The payload capabilities and endurance limitations for a coal-fired COGAS ship are presented and compared with those of a conventional oil-fired ship to show the possible fuel cost savings.
Considerations in Retrofitting Gas Turbine Governors
Authors: Paling William M. 
Published: April 2015

The paper examines some aspects which should be examined in specifying and selecting replacement gas turbine governors.
It explores the subject from the point of view of the engine manufacturer in his investigations and studies of the original supplied governor. It examines some aspects of the liaison required between the governor engineer, the User and the mechanical, combustion, performance and heat transfer engineers to define governor functions.
Having established functional requirements it then considers aspects such as reliability, failure mode, documentation and a plan for the retrofit.
Fuel Effects on Aircraft Combustor Emissions
Authors: Reeves Curtis M. , Lefebvre Arthur H. 
Published: April 2015

Results of an analytical program to determine the effects of broad variations in fuel properties on the pollutant emissions generated by several prominent turbojet engine combustion systems, including both tubo-annular and annular configurations, are presented. Measurements of mean drop size conducted at representative engine operating conditions are used to supplement the available experimental data on the effects of combustor design parameters, combustor operating conditions, and fuel type, on pollutant emissions.
The results of the study indicate that the fuel’s physical properties that govern atomization quality and evaporation rates have a significant effect on the emissions of carbon monoxide and unburned hydrocarbons. Analysis of the available experimental data shows that the influence of fuel chemistry on the emissions of carbon monoxide, unburned hydrocarbons, and oxides of nitrogen, is small. Smoke emissions are found to be strongly dependent on combustion pressure, primary-zone fuel/air ratio, and the mode of fuel injection (pressure atomization or airblast). Fuel chemistry, as indicated by hydrogen content, is also important.
Equations are presented for the correlation and/or prediction of exhaust emissions in terms of combustor size, combustor geometry, engine operating conditions, fuel spray characteristics, and fuel type.
A Gas Turbine Cogeneration Plant With a Gross Electrical Efficiency of Over 50%
Authors: Broekhuizen A. L. , van Lavieren R. R. , Kamminga P. 
Published: April 2015

District heating projects in the Netherlands are cogeneration projects with special emphasis on high-efficiency power generation. Together with their customer N.V. IJsselcentrale, Thomassen International B.V., designed a cogeneration system based on gas and steam turbines. The system has following main features:
- the gross electrical efficiency of the system is over 50%, which is a highly remarkable achievement in power generation
- the main components, 2 gas turbines, a steam turbine and one generator are mounted in line on a single shaft.
Successful start up of the plant happened in November 1985, performance tests have shown the target of power generation with an efficiency of 50% is met.
Selection of High Performance Low Flow Compressors
Authors: Sayyed S. 
Published: April 2015

With rapidly escallating energy costs, the need to use energy as efficiently and economically as possible has led to new development programs particularly in the low flow areas. New techniques in the design of impellers as well as stationary flow passages have been developed to produce highly efficient compression stages, and at the same time calculation methods to accurately predict the aerodynamic performance for low flow applications are being continually upgraded to provide a reliable and efficient machine to be employed in the emerging applications.
This paper provides some of the insights, which need to be considered when selecting low flow high performance centrifugal compressors.
The Part-Load Performance of a Gas Turbine Engine With Two Turbines Working in Parallel
Authors: Najjar Yousef S. H. , Aldoss Taha K. 
Published: April 2015

To reduce the inefficiency and the drawbacks incurred by reheat in a gas turbine engine with the two turbines in series, a parallel arrangement is investigated. The combustion gases expand to atmospheric pressure in each turbine. One of the turbines drives the compressor to which it is mechanically coupled while the other develops the power output of the plant.
Two methods of control for the reduction of power are considered:
a) Varying the fuel supply to the combustion chambers so that the inlet temperature to the turbine driving the compressor is constant, while the inlet temperature to the power turbine is reduced.
b) Reducing both temperatures while keeping them equal.
The effects of turbines inlet temperatures, pressure ratio and pressure loss in combustion chambers on the cycle efficiency and power output are studied and a sensitivity analysis is carried out, with the aid of a specially constructed computer program.
The first method of control proved to be superior.
Lifetime Prediction Under Constant Load Creep Conditions for a Cast Ni-Base Superalloy
Authors: Castillo R. , Koul A. K. , Toscano E. H. 
Published: April 2015

Creep and stress-rupture properties of cast IN738LC turbine blades have been analyzed to review the suitability of the Monkman-Grant relationship as a reliable life prediction method where
t r ε . s m = C
and m and C are material constants. The constants m and C in the Monkman-Grant relationship are temperature dependent and the relationship predicts lives within a factor of ± 4 relative to the observed values. A modified form of this relationship is derived where,
- b t r n 1 + t r ε . s m 1 = K
and b, n, m1 and K are material constants. The modified relationship is more accurate and predicts lives within a factor of 2 relative to the observed values. The constants b, n, m and k are independent of stress and temperature.