scholarly journals A Quasi-Three Dimensional Analysis of Choking Flow for Radial Gas Turbines

1978 ◽  
Author(s):  
Yoshiyuki Nakase ◽  
Junichiro Fukutomi ◽  
Masanobu Inubushi ◽  
Takashi Watanabe ◽  
Yoshiyasu Hama ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Energy Recovery ◽  
Three Dimensional ◽  
Layer Growth ◽  
Meridional Plane ◽  
Mixed Flow ◽  
Numerical Examples ◽  
Annular Cascade ◽  
Boundary Layer Growth

A quasi-three dimensional.flow analysis has previously been reported for a mixed flow impeller by one of the present authors. In the analysis, the velocity gradient method has been used in meridional plane and the rotating annular cascade theory has been used for blade-to-blade solution. In this report, the analysis is generalized to allow prediction and analysis of choking flow for a radial inflow gas turbine. Moreover, this analysis is corrected to include passage contraction effects and passage loss effects due to boundary-layer growth. The efficiency and choking flow rate of gas turbine may be obtained in a single computer run without the complicated throat area estimation. Some numerical examples for a burst furnace gas energy recovery turbine are presented.

An Analysis of Flow Through a Mixed Flow Impeller

1972 ◽  
Vol 94 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Yasutoshi Senoo ◽  
Yoshiyuki Nakase
Keyword(s):  
Finite Number ◽  
Flow Condition ◽  
Three Dimensional ◽  
Meridional Plane ◽  
Surfaces Of Revolution ◽  
Mixed Flow ◽  
Numerical Examples ◽  
Orthogonal Coordinate System ◽  
Plane Solution ◽  
Flow Through

In this report, a method of analyzing steady, three-dimensional, subsonic, nonviscous flow through a turbomachine with arbitrary hub and shroud shapes and with a finite number of blades is presented. In order to make the analysis manageable, the stream surfaces are assumed to be axisymmetric. Position and shape of these surfaces, which depend upon the work of blades, are obtained by a meridional plane solution using a quasi-orthogonal coordinate system. The flow condition on these surfaces of revolution and the work of blades are obtained by a new blade-to-blade solution and the results are used to improve the meridional plane solution. This procedure is repeated until solution converges. Some numerical examples are given.

Unsteady Lifting Surface Theory for a Rotating Cascade of Swept Blades

1989 ◽  
Author(s):  
Hidekazu Kodama ◽  
Masanobu Namba
Keyword(s):  
Three Dimensional ◽  
Acoustic Power ◽  
Aerodynamic Characteristics ◽  
Blade Loading ◽  
Surface Theory ◽  
Numerical Examples ◽  
Lifting Surface ◽  
Blade Flutter ◽  
Annular Cascade ◽  
Remarkable Reduction

A lifting surface theory is developed to predict the unsteady three-dimensional aerodynamic characteristics for a rotating subsonic annular cascade of swept blades. A discrete element method is used to solve the integral equation for the unsteady blade loading. Numerical examples are presented to demonstrate effects of the sweep on the blade flutter and on the acoustic field generated by interaction of rotating blades with a convected sinusoidal gust. It is found that increasing the sweep results in decrease of the aerodynamic work on vibrating blades and also remarkable reduction of the modal acoustic power of lower radial orders for both forward and backward sweeps.

Three-Dimensional Time-Resolved Flow Field in the First and Last Turbine Stage of a Heavy Duty Gas Turbine: Part II — Interpretation of Blade Pressure Fluctuations

2000 ◽  
Author(s):  
Martin von Hoyningen-Huene ◽  
Wolfram Frank ◽  
Alexander R. Jung
Keyword(s):  
Flow Field ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Fluctuations ◽  
Three Dimensional ◽  
Potential Interaction ◽  
Heavy Duty ◽  
Turbine Stage ◽  
Count Ratio ◽  
Heavy Duty Gas Turbine

Unsteady stator-rotor interaction in gas turbines has been investigated experimentally and numerically for some years now. Most investigations determine the pressure fluctuations in the flow field as well as on the blades. So far, little attention has been paid to a detailed analysis of the blade pressure fluctuations. For further progress in turbine design, however, it is mandatory to better understand the underlying mechanisms. Therefore, computed space–time maps of static pressure are presented on both the stator vanes and the rotor blades for two test cases, viz the first and the last turbine stage of a modern heavy duty gas turbine. These pressure fluctuation charts are used to explain the interaction of potential interaction, wake-blade interaction, deterministic pressure fluctuations, and acoustic waveswith the instantaneous surface pressure on vanes and blades. Part I of this two-part paper refers to the same computations, focusing on the unsteady secondary now field in these stages. The investigations have been performed with the flow solver ITSM3D which allows for efficient simulations that simulate the real blade count ratio. Accounting for the true blade count ratio is essential to obtain the correct frequencies and amplitudes of the fluctuations.

Unsteady Flow at the Outlet of the High Specific Speed Centrifugal Compressor Impeller

1984 ◽  
Author(s):  
Fumikata Kano ◽  
Takafumi Shirakami
Keyword(s):  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Coal Gasification ◽  
Three Dimensional ◽  
Axial Direction ◽  
Navier Stokes ◽  
Meridional Plane ◽  
Mixed Flow ◽  
Navier Stokes Equation ◽  
Specific Speed

The unsteady flow at the outlet of the high specific speed mixed flow Impeller was studied. The specific speed is 500 (m3/min)1/2 · rpm · m−3/4. The flow is strongly influenced by the impeller blading. The other hand, the flow influences the performance of the stationary vanes downstream of the impeller. The flow path at the outlet of the mixed flow impeller is inclined to the axial direction and is curved in the meridional plane. The study was carried out to develop the 30 MW centrifugal compressor. This compressor is used in the field of the coal gasification, the geothermal power generation, etc. The distributions of flow velocity, pressure and temperature of three dimensional flow were measured using a high sensitive pressure transducer and a total temperature probe. The flow was surveyed across the entire passage at about ten axial locations including endwall boundary layer. A theoretical analysis was also carried out using the linearized Navier-Stokes equation.

The boundary layer due to a three-dimensional vortex loop

1987 ◽  
Vol 185 ◽  
pp. 569-598 ◽  
Author(s):  
S. Ersoy ◽  
J. D. A. Walker
Keyword(s):  
Boundary Layer ◽  
Three Dimensional ◽  
Symmetry Plane ◽  
Layer Growth ◽  
Plane Wall ◽  
Vortex Loop ◽  
Loop Shape ◽  
Layer Flow ◽  
Boundary Layer Growth ◽  
Moving Vortex

The nature of the boundary layer induced by the motion of a three-dimensional vortex loop towards a plane wall is considered. Initially the vortex is taken to be a ring approaching a plane wall at an angle of attack in an otherwise stagnant fluid; the ring rapidly distorts into a loop shape due to the influence of the wall and the trajectory is computed from a numerical solution of the Biot-Savart integral. As the vortex loop moves, an unsteady boundary-layer flow develops on the wall. A method is described which allows the computation of the flow velocities on and near the symmetry plane of the vortex loop within the boundary layer. The computed results show the development of a variety of complex three-dimensional separation phenomena. Some of the solutions ultimately show strong localized boundary-layer growth and are suggestive that a boundary-layer eruption and a strong viscous-inviscid interaction will be induced by the moving vortex.

Ongoing Development and Recent Results of the Research in the Swedish Gas Turbine Centre (GTC)

2004 ◽  
Author(s):  
Sven Gunnar Sundkvist ◽  
Michael Andersson ◽  
Bogdan Gherman ◽  
Andreas Sveningsson ◽  
Damian Vogt
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Industrial Development ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Life Time ◽  
Research Areas ◽  
Verification Methods ◽  
Acoustic Instabilities ◽  
Research Students

This paper describes a way of co-operation between industries, universities and government that has proven to be very fruitful. The Swedish Gas Turbine Centre (GTC) is constituted as a research consortium between technical universities and gas turbine industry. The overall goal of the centre, that was founded in 1996 on a governmental initiative, is to build up a basis of knowledge at Swedish universities to support the industrial development in Sweden of gas turbines of the future with expected requirements on low emissions, high efficiencies, high availability, and low costs. Since the start the research has had a focus on high temperature components of gas turbines (combustion chamber and turbine). This is also reflected in the on-going development phase where the research program consists of four project areas: cooling technology, combustion technology, aeroelasticity, and life time prediction of hot components. The projects are aiming at developing design tools and calculation and verification methods within these fields. A total of eleven research students (among them one industrial PhD student) are active in the centre at present. Numerical analysis as well as experimental verification in test rigs are included. The program has so far produced eleven Licentiate of Engineering and five PhD. On-going activities and recent results of the research in the four research areas are presented: • A new test rig for investigation of time-dependent pressures of three-dimensional features on a vibrating turbine blade at realistic Mach, Reynolds and Strouhal numbers and first experimental results. • Results of numerical simulations of heat loads on turbine blades and vanes, especially platform cooling. • First results of numerical investigations of combustion and thermo-acoustic instabilities in gas turbine chambers. • Experimental investigation of crack propagation in gas turbine materials using the scanning electron microscope (SEM).

Three-Dimensional Flow Field in Rocket Pump Inducers—Part 1: Measured Flow Field Inside the Rotating Blade Passage and at the Exit

1973 ◽  
Vol 95 (4) ◽  
pp. 567-578 ◽  
Author(s):  
B. Lakshminarayana
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Layer Growth ◽  
Surface Boundary ◽  
Suction Surface ◽  
Flow Losses ◽  
Rotating Blade ◽  
Order Of Magnitude ◽  
Measured Flow ◽  
Boundary Layer Growth

The measurement of the flow field within the rotating passages as well as three-dimensional characteristics of the exit flow of an inducer model is reported in this paper. The flow within the inducer is probed by means of rotating pitot probe and pressure transfer device and at the exit by means of three hot wires located in three coordinate directions. In a high solidity inducer (4 bladed), considerable boundary layer growth is observed from hub to mid radius, while the flow from mid radius to tip is found to be highly complex, due to interaction of pressure and suction surface boundary layers and the resulting radial inward flow. The flow losses and wall shear stress derived from these measurements are found to be considerably higher than the corresponding stationary channel. The radial velocities are found to be of the same order of magnitude as axial velocities. Considerable improvement in the flow field is observed when the number of blades is decreased from four to three.

A Theory for Boundary Layer Growth on the Blades of a Radial Impeller Including Endwall Influence

1983 ◽  
Vol 105 (3) ◽  
pp. 403-411
Author(s):  
H. Ekerol ◽  
J. W. Railly
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Three Dimensional ◽  
Prediction Method ◽  
Suction Side ◽  
Layer Growth ◽  
Secondary Flows ◽  
Curvature Effects ◽  
Momentum Integral ◽  
Boundary Layer Growth

Experimental data on the wall shear stress of a turbulent boundary layer on the suction side of a blade in a two-dimensional radial impeller is compared with the predictions of a theory which takes account of rotation and curvature effects as well as the three-dimensional influence of the endwall boundary layers. The latter influence is assumed to arise mainly from mainstream distortion due to secondary flows created by the endwall boundary layers, and it appears as an extra term in the momentum integral equation of the blade boundary layer which has allowance, also for the Coriolis effect; an appropriate form of the Head entrainment equation is derived to obtain a solution and a comparison made. A comparison of the above theory with the Patankar-Spalding prediction method, modified to include the effects of Coriolis (including mixing length modification, MLM), is also made.

Paper 7: Radial Gas Turbines

1968 ◽  
Vol 183 (14) ◽  
pp. 59-70 ◽  
Author(s):  
M. C. S. Barnard ◽  
R. S. Benson
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Future Trends ◽  
One Dimensional ◽  
Optimum Speed ◽  
Speed Range ◽  
Rotor Losses ◽  
Rotor Loss

The optimum speed range for radial gas turbines is given and the practical advantages of this type of turbine are discussed with reference to some current applications. One-dimensional flow considerations are briefly reviewed and the representation of nozzle and rotor loss data described. Two- and three-dimensional flows in the rotor turbine are examined in the light of recent numerical techniques. Comparison is made of the predictions in the rotor losses using these techniques and some experimental results. The design performance of a small radial gas turbine is given. The mechanical and thermal stresses of rotor life together with materials and methods of manufacture are examined. The results of service experience are reviewed with particular reference to rotor and nozzle life. Future trends in development of the radial gas turbine are indicated.

On the Use of Helmholtz Resonators for Damping Acoustic Pulsations in Industrial Gas Turbines

2004 ◽  
Vol 126 (2) ◽  
pp. 271-275 ◽  
Author(s):  
V. Bellucci ◽  
P. Flohr ◽  
C. O. Paschereit ◽  
F. Magni
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Three Dimensional ◽  
Low Frequency ◽  
Operating Regime ◽  
Acoustic Response ◽  
Combustion Chambers ◽  
Helmholtz Resonators ◽  
Industrial Gas Turbines ◽  
Significant Extension

In this work, the application of Helmholtz resonators for damping low-frequency pulsations in gas turbine combustion chambers is discussed. We present a nonlinear model for predicting the acoustic response of resonators including the effect of purging air. Atmospheric experiments are used to validate the model, which is employed to design a resonator arrangement for damping low-frequency pulsations in an ALSTOM GT11N2 gas turbine. The predicted damper impedances are used as the boundary condition in the three-dimensional analysis of the combustion chamber. The suggested arrangement leads to a significant extension of the low-pulsation operating regime of the engine.

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