Comparison of experimental, 3D and 1D model for a mixed-flow turbine under pulsating flow conditions

The pulse flow performance of a turbocharger turbine is known to be different than its corresponding steady flow performance. This often leads to less-than-satisfactory 1D engine model prediction. In this study, the effectiveness of a 1D pulse flow turbine model is assessed against experimental data with the aid of 3D CFD model. The turbine under study is a single-entry variable geometry mixed-flow turbine. The result shows highly comparable pulse flow swallowing capacity and actual power characteristics between 1D and 3D models. The over-prediction in 1D actual power magnitude is found to be due to the simplification of combining nozzle and rotor stage pressure loss together.