車両用過給機の脈動流下における非定常流れ

抄録

The turbine gas inflow in a turbocharger exhibits pulsating behavior because of the opening and closing of engine valves. Turbocharger data for engine design is usually computed for steady flow conditions. However actual turbochargers operate under pulsating flow which is reported to decrease turbine efficiency. In this study, experimental investigation and Computational Fluid Dynamics (CFD) under pulsating flow condition were performed. Unsteady performance measurement and Particle Image Velocimetry (PIV) measurement were performed by using a model turbine test rig. RANS and DES were used. On the computational side, it was noted that DES is needed to simulate the flow pattern of a turbine outlet under pulsating flow.