Simulation investigation on pulsating flow field in turbocharger turbine

For understanding well vehicle turbocharger turbine performance under pulsating flow condition to matching better with engine, the unsteady flow field in nozzled radial turbine was investigated by numerical simulation, especially using phase shift method to compute the turbine instant efficiency. Results show that both turbine mass flow and efficiency characteristics are of unusual hysteresis to the pressure ratio under pulsating flow intake condition. Rotor incidence variation in pulsating cycle influences strongly velocity field in turbine passage. Rotor power variation rule corresponds to that of the turbine inlet pressure. Increasing turbine design flow rate properly is beneficial to increase of turbine ability to utilize engine exhaust energy.