Computation of the Unsteady Transonic Flow in Harmonically Oscillating Turbine Cascades Taking into Account Viscous Effects.

Abstract

This paper presents the numerical results of a code for computing the unsteady transonic viscous flow in a two-dimensional cascade of harmonically oscillating blades. The flow field is calculated by a Navier-Stokes code, the basic features of which are the use of an upwind flux vector splitting scheme for the convective terms (Advection Upstream Splitting Method), an implicit time integration and the implementation of a mixing length turbulence model. For the present investigations two experimentally investigated cases have been selected in which the blades had performed tuned harmonic bending vibrations. The results obtained by the Navier- Stokes code are compared with experimental data, as well as with the results of an Euler method.