Numerical Computations of Pulsatile Flow in a Turbo-Charger

Authors: Hellström, F., Fuchs, L.F.
Document Type: Conference
Pubstate: Published
Journal: 46th AIAA Aerospace Sciences Meeting and Exhibit, 7-10 January 2008, Reno, Nevada
Volume: AIAA-2008-735  
Year: 2008


The non-pulsatile and pulsatile three-dimensional flow in the turbine part of a radial turbo-charger have been computed with different modeling approaches for the turbulence; using the Reynolds Averaged Navier-Stokes (RANS) and Large Eddy Simulations (LES). To asses the effect of inlet condition three different cases with different frequencies and mass flow pulses have been considered. The computations show that the mass flow and pressure is out of phase, and the phase shift is not constant during the engine cycle, which also affects the calculated isentropic efficiency. The flow field in turbine has been further studied and the vortex cores are visualized to give a better insight into the unsteady flow field and the effects of the inflow pulsations.