INLET BOUNDARY CONDITION STUDY FOR UNSTEADY TURBINE PERFORMANCE PREDICTION USING 1-D MODELING

Abstract

This paper presents the appropriate inlet boundary condition settings for turbocharger turbine unsteady performance prediction using one-dimensional modelling without the full access to pulsating engine exhaust flow parameter. Three different settings of inlet boundary conditions are discussed in this paper, each requiring different level of experimental result inputs. Two basic flow parameters, instantaneous static pressure and average static temperature of exhaust flow are the fundamental inputs for all inlet boundary condition settings presented. In general, all boundary conditions showed acceptable unsteady turbine non-dimensional parameter prediction, particularly the hysteresis of unsteady turbine swallowing capacity performance. Despite, the presence of steady state turbine performance map was found to further enhance the quality of dimensional flow parameters prediction. The strength and weakness of each boundary condition setting in flow performance prediction are analyzed and discussed. Finally, a boundary condition that included the steady state inlet flow Mach number gave the most compromise results in terms of unsteady non-dimensional and dimensional parameters prediction.