Radial inflow turbines have established their place in small power units and turbochargers which usually operate under highly unsteady gas flows. The present numerical study is an aerodynamic characterization of the steady and unsteady gas flows through the components of a twin-entry radial turbine with an asymmetrical volute, with an insight on the volute/rotor interactions and the effects of pulsatile flow. The details of the flow structures were possible to obtain by considering the full rotor blades simulations. Examination of the both sides of volute has revealed much more energy conversion with respect to the shroud side and the tongue influence is clearly depicted by a low momentum due to mixing till a tangential position. The rotor flow is characterized by intense secondary flows provoking migration of low energy fluid from hub to shroud and interacting with tip leakage flow. Spectral analysis of the pressure fluctuations recorded at different interfaces has revealed high unsteadiness which may be characterized by a space-time periodic behaviour and described by a double Fourier decomposition. This has led to the determination of different pressure fluctuation frequencies arising during the turbine working time and prevailing modes and their originating sources.
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