Modeling of three dimensional unsteady flow effects in axial flow turbine rotors

1998 ◽  
Vol 25 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Eui Soo Yoon ◽  
Byung Nam Kim ◽  
Myung Kyoon Chung
Keyword(s):  
Unsteady Flow ◽  
Three Dimensional ◽  
Axial Flow ◽  
Turbine Rotors ◽  
Flow Effects

Prediction of 3D-Unsteady Flow in an Air Turbine and a Transonic Compressor Including Blade Gap Flow and Blade Row Interaction

1997 ◽  
Author(s):  
Alexander R. Jung ◽  
Jürgen F. Mayer ◽  
Heinz Stetter
Keyword(s):  
Unsteady Flow ◽  
Three Dimensional ◽  
Axial Flow ◽  
Navier Stokes ◽  
Transonic Compressor ◽  
Gap Flow ◽  
Air Turbine ◽  
Flow Phenomena ◽  
3D Unsteady Flow ◽  
Flow Effects

This paper presents the results of three-dimensional unsteady Navier-Stokes simulations of the flow in a transonic compressor stage with inlet guide vanes and an axial flow air turbine stage with two identical stators for which detailed unsteady experimental data are available. Various unsteady flow phenomena are shown. The focus in the computations are stator/rotor interaction effects. Of special interest are their influences on the flow field downstream of the interface regions. The secondary flow effects are visualized via vector plots. The numerical results are compared with the experimental results. Although there is a good agreement in the major flow phenomena local deviations can be observed.

scholarly journals Experimental and Computational Study of the Unsteady Flow in a 1.5 Stage Axial Turbine With Emphasis on the Secondary Flow in the Second Stator

1998 ◽  
Author(s):  
Ralf E. Walraevens ◽  
Heinz E. Gallus ◽  
Alexander R. Jung ◽  
Jürgen F. Mayer ◽  
Heinz Stetter
Keyword(s):  
Unsteady Flow ◽  
Secondary Flow ◽  
Computational Study ◽  
Three Dimensional ◽  
Cross Flow ◽  
Axial Flow ◽  
Time Dependent ◽  
Flow Structures ◽  
Mean Flow ◽  
Dependent Flow

A study of the unsteady flow in an axial flow turbine stage with a second stator blade row is presented. The low aspect ratio blades give way to a highly three-dimensional flow which is dominated by secondary flow structures. Detailed steady and unsteady measurements throughout the machine and unsteady flow simulations which include all blade rows have been carried out. The presented results focus on the second stator flow. Secondary flow structures and their origins are identified and tracked on their way through the passage. The results of the time-dependent secondary velocity vectors as well as flow angles and Mach number distributions as perturbation from the time-mean flow field are shown in cross-flow sections and azimuthal cuts throughout the domain of the second stator. At each location the experimental and numerical results are compared and discussed. A good overall agreement in the time-dependent flow behaviour as well as in the secondary flow structures is stated.

The exploitation of three-dimensional flow in turbomachinery design

1998 ◽  
Vol 213 (2) ◽  
pp. 125-137 ◽  
Author(s):  
J. D. Denton ◽  
L Xu
Keyword(s):  
Three Dimensional ◽  
Axial Flow ◽  
Field Calculation ◽  
3D Flow ◽  
Three Dimensional Flow ◽  
Approximate Methods ◽  
Blade Row ◽  
3D Effects ◽  
Flow Effects ◽  
Turbomachinery Design

Many of the phenomena involved in turbomachinery flow can be understood and predicted on a two-dimensional (2D) or quasi-three-dimensional (Q3D) basis, but some aspects of the flow must be considered as fully three-dimensional (3D) and cannot be understood or predicted by the Q3D approach. Probably the best known of these fully 3D effects is secondary flow, which can only be predicted by a fully 3D calculation which includes the vorticity at inlet to the blade row. It has long been recognized that blade sweep and lean also produce fully 3D effects and approximate methods of calculating these have been developed. However, the advent of fully 3D flow field calculation methods has made predictions of these complex effects much more readily available and accurate so that they are now being exploited in design. This paper will attempt to describe and discuss fully 3D flow effects with particular reference to their use to improve turbomachine performance. Although the discussion is restricted to axial flow machines, many of the phenomena discussed are equally applicable to mixed and radial flow turbines and compressors.

scholarly journals Unsteady Upstream Effects in Axial-Flow Supersonic Compressor Stages

1979 ◽  
Author(s):  
H. E. Gallus ◽  
D. Bohn ◽  
K.-D. Broichhausen
Keyword(s):  
Static Pressure ◽  
Three Dimensional ◽  
Axial Flow ◽  
Three Dimensional Flow ◽  
Outlet Angle ◽  
Flow Disturbances ◽  
Flow Information ◽  
Design Speed ◽  
Flow Effects ◽  
Rotor Flow

An investigation of the unsteady flow effects in a supersonic compressor stage is reported. Semiconductor transducers mounted in the casing, a stroboscopic schlieren-technique and probes equipped with semiconductor transducers were used to obtain unsteady static pressure, flow visualization and three-dimensional flow information, respectively. The throttling effect during the starting procedure of the stage was found to produce changes of the quasi-steady and unsteady rotor flow pattern as well as changes in both amplitude and frequency of the flow disturbances at the inlet. The conditions which are generated in this way at design speed are different from those reached by back-pressure imposed on the started supersonic rotor at the same speed. The relative position of rotor and stator has an influence on the flow field only below design speed. One can conclude from the measurements of the rotor outlet angle that these effects generated by throttling the rotor flow by a stator during the starting procedure might be avoided with movable stator blades.

Three-dimensional unsteady flow in an axial flow turbine

1985 ◽  
Vol 1 (1) ◽  
pp. 29-38 ◽  
Author(s):  
O. P. Sharma ◽  
T. L. Butler ◽  
H. D. Joslyn ◽  
R. P. Dring
Keyword(s):  
Unsteady Flow ◽  
Three Dimensional ◽  
Axial Flow

scholarly journals An Investigation of Spanwise Mixing in Multistage Axial Flow Compressors

1992 ◽  
Author(s):  
S.-M. Li ◽  
M.-Z. Chen
Keyword(s):  
Secondary Flow ◽  
Turbulent Diffusion ◽  
Flow Model ◽  
Three Dimensional ◽  
Axial Flow ◽  
Equation System ◽  
Meridional Flow ◽  
Flow Effects ◽  
Annular Cascade ◽  
Axial Flow Compressors

An equation system has been deduced for meridional throughflow fields of multistage axial flow compressors, presenting different kinds of spanwise mixing effects of the fields in a unified form. The spanwise mixing in compressors is caused by three kinds of effects, molecular motion, turbulent diffusion, and circumferential non–uniformities, the last of which includes secondary flow effects and others. This equation system thus unifies the two models for spanwise mixing analyses by Adkins & Smith (1981) and Gallimore & Cumpsty (1986). The turbulent diffusion in the two–dimensional (2–D) meridional fields is determined by complex three–dimensional (3–D) shear flows in compressors, rather than the 2–D shearing alone, so a turbulence model for 2–D meridional flow calculations is proposed on the basis of a simplified 3–D shearing structure in compressors. The circumferentially non–uniform correlation terms in the equation system have been modeled on the basis of Adkins and Smith (1981) secondary flow model and the experimental data for annular cascade wakes. The results obtained agree well with the experiments for five compressors. The results also show some improvement over the previous theories.

Sign in / Sign up

Export Citation Format

Share Document