Ecoulement à débit partiel dans un canal inter-aube de roue radiale. Simulation numérique

Partial flow rate in a radial impeller channel between blades. Numerical simulation

Laboratoire de Mécanique de Lille

Abstract

Unsteady phenomena in the flows of rotating machine wheels may be prompted by the passage of the blade cascade, by unsteady separation, or stall or by other spatial or space-time instabilities. In incompressible fluid, the problem often arises of computing the pressure, which requires an exact solution of a Poisson problem at each time step. We have developed a LES type numerical scheme for simulating large eddies in incompressible unsteady flows over long periods. This scheme uses a combination spectral-singularity solution of the Poisson problem for the pressure. Simulations with this method were compared with available experimental data for the SHF wheels. The flow in a single channel subjected to a periodicity condition was simulated for the design conditions (Qn) et partial flow rate (0,3Qn).