Turbocharger development is based on performance maps arising through steady state measurements, although the flow through the engine-turbocharger system is highly unsteady. This paper investigates the potential for integrating the effects from unsteady flow in the turbine map, in order to enhance the performance of the ICE-turbocharger system. It is, also, an initial attempt to set the framework for more accurate one-dimensional turbine simulations in order to improve the selection of turbocharger components and their matching with the ICE. The development of ‘equivalent unsteady’ maps is presented, based on energy-weighted averaging of available, unsteady, experimental data and its deviations from quasi-steady performance. The maps are subsequently used for a one dimensional (1D) simulation of a turbocharged diesel engine running at 800 RPM and 1600 RPM. A comparative assessment with results from simulations using a conventional steady-state map has shown important differences in turbine parameters (up to 12% lower efficiency and 6% lower mass flow parameter) but minor differences, of less than 1% in terms of engine performance and fuel consumption.

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