Numerical Study of the Turbulent Air Flow through the Turbocharger Compressor Using Different Rotor Shapes

The turbulent air flow through the turbocharger is studied, considering the full stage of the centrifugal compressor, consisting of an air inlet, leading to an impeller that discharges the air radially through a vaneless diffuser in the volute. The objective of this study is the prediction of the influence of impeller blades geometry on the flow local characteristics (velocity and pressure) and on the local characteristics of turbulence represented by the standard k-ε model, for this, three types of impellers that have the same size and the same number of blades are considered, they differ only in inlet and exit blade angle. All simulations are carried out for the same rotational speed of 100000 rpm, and several points of the operating range, it is chosen for representing the results one of these points at flow rate of 0.47 kg/s, the velocity fields is presented in the axial plane, and transverse plan, whereas for the turbulence intensity we show the diffuser with each type of impeller to give an idea about the distribution of turbulence intensity in the diffuser. It is found from the computational fluid dynamics analysis that the rotor design presents a considerable effect not only on the fluid flow field and turbulence characteristics, but also on the performances and operating range of the turbocharger compressor.