The turbocharger is the key enabler for energy conservation in Internal Combustion Engine (ICE). A turbine
of a turbocharger is fed by highly pulsating flow due to the reciprocating engine, resulting in different
behavior from that at steady conditions. This paper investigates the behavior of a mix-flow turbine
under pulsating conditions via an analytical model and an in-house developed 1-D unsteady code
ONDAS. Firstly, an analytical model of the ‘unsteadiness’ based on the mass flow imbalance is built
and the mechanism of the unsteady behavior is discussed in details. Next, a 1-D unsteady model of
the turbine under pulsating conditions is established and validated by experimental results. Finally,
influence of the frequency, the magnitude and their product on unsteady behavior of the turbine is
investigated by the reduced order model for further exploration of the analytical model. The investigation
clearly demonstrates the impact of pulsating flow on the unsteady performance and unveils the mechanism
of the ‘unsteadiness’ of turbine under pulsating conditions.