Steady-state flow refers to the condition where all the flow parameters do not change over the time throughout the entire domain.
Otherwise, it is called transient (unsteady) flow. A steady-state flow simulation can generally save a lot of computer resources and
CPU time. For turbo-dynamic blood pumps and industrial turbomachinery, even for the steady-state flow simulations, interactive effects
between the rotating and stationary components are taken into account by numerical coupling methods such as frozen rotor,
and implicit coupling under multiple frames of reference (MFR).