Turbocharger matching methodology for improved exhaust energy recovery

Abstract

Current engine simulation codes rely on user-input turbine maps to predict the performance of turbocharged engines. These experimentally obtained maps are limited in range as they are typically obtained through the use of an aerodynamically limited turbine loading device, the compressor. In order to extend the range of the map for simulation, several fitting techniques are utilized in order to obtain the values of efficiency and mass flow over the entire range of pressure ratio for all speeds. This investigation compares predicted turbine maps, obtained from narrow ranges of pressure ratio with more reliable, wider maps obtained experimentally for the same turbines by replacing the compressor with a dynamometer. The outcome of this investigation can be used to improve the fitting of efficiency and mass flow rate curves in engine simulation software.