Abstract
Turbine rotor shapes for a variable geometry turbocharger have been investigated by numerical simulations in order to improve the low speed performances of a supercharged engine. With focusing on the vortex flow generated inside rotors at the low flow rate, the rotor blade shapes to make the vortex flow diminish were examined and designed. The application of newly designed turbine rotor to an actual turbocharger for a diesel engine has brought about improvements in the turbine efficiency at the lowest flow rate without performance decrement at the higher flow rate.
