Simulation of gas water two-phase flow in diesel turbocharger

Numerical simulation of a gas water two-phase flow in Diesel Turbocharger has been carried out using computational fluid dynamics solution of the Eulerian Reynolds-averaged Navier-Stokes equations for the continuum gas phase and the Lagrangian particle tracking method for the discrete water droplets. A generic diesel turbocharger configuration was chosen, which has an upstream duct inlet and a downstream blade ring outlet. Three identical water injectors were evenly distributed in the circumferential direction and located upstream of the blades. Simulation considered water injection at an angle of 30o from the centerline with two water pump pressures of 4 bars and 8 bars. The process of liquid droplet break-up has been modeled using the Blob model for primary break-up and the cascade atomization breakup (CAB) and the Reitz and Diwakar breakup (RDB) models for secondary break-up. The results show that the predicted water droplet coverage and the blade temperature drop were in good agreement with experimental measurements. Simulations also showed that for the two water pump pressures considered, the water droplet coverage and distribution patterns on the blade ring change little, indicating the need to increase the number of injectors for better water washing performance.