New phenomenological and power-based approach for determining the heat flows of a turbocharger directly from hot gas test data

Abstract

Heat transfer and inhomogeneous flows in the turbine inhibit the calculation of the isen-tropic efficiencies from hot gas test data using conventional methods. In previous works the basis for such a calculation has been built such as special measurement devices and a power-based approach for calculating the heat flows. The main objective of the present work is the calculation of the isentropic turbine efficiencies and further development of the approach for obtaining isentropic compressor efficiencies from hot gas test data. The turbocharger is described aerodynamically and thereby the friction power can be calculated by setting up the power balance. For validation of the compressor, adiabatic measurements are used as well as CFD simulations for the turbine. Reasons for the latter are changing inlet conditions that do not allow the transfer of adiabatic data to diabatic or hot conditions.