Title: Simulation of unsteady compressible flow in turbomachinery

Authors: O. Schafer

Addresses: ABB Turbo Systems AG, CH-5401, Baden, Switzerland

Abstract: Two examples are given of how an unsteady quasi-three-dimensional (Q-3D) computational method can be used to simulate essential phenomena of a three-dimensional unsteady flow. The first example is the flow within a turbine stage with following gas exhaust casing (GEC) of a turbocharger. It is demonstrated that a Q-3D simulation is an important tool in understanding the complicated pulse charging process. It closes the gap between a one-dimensional quasi-steady simulation of the complete process and the steady three-dimensional simulation of components within the process. It is further demonstrated that a combination of all three simulation models is possible to get detailed insight. Detailed unsteady blade pressure measurements are available for the second example, a 1½ stage compressor. A grid dependency study is performed and it is shown that fine grids with more than 5000 grid points per blade channel are necessary to get a good agreement with the measured data.

Keywords: flow modelling; quasi-three-dimensional (Q-3D) computation; turbines; turbomachinery; unsteady compressible flow.

DOI: 10.1504/PCFD.2002.003212

Progress in Computational Fluid Dynamics, An International Journal, 2002 Vol.2 No.1, pp.1 - 8

Published online: 19 Aug 2003 *

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