Computations of homogeneous multiphase real fluid flows at all speeds

Abstract

Computations of all-speed multiphase real fluid flows for aerospace launch vehicles are known to be very demanding, owing to several issues that include robust capturing of two-phase shock/phase discontinuity and proper scaling of numerical flux at steady/unsteady all-speed flows. This paper deals with the development of computational components to overcome difficulties arising from these issues. First, the shock-discontinuity-sensing term used in the two-phase AUSMPW+ and RoeM schemes is modified because the existing shock-discontinuity-sensing term is not suitable for complex equation of state of real fluids. The accuracy of the two-phase AUSMPW+ and RoeM schemes for unsteady low-Mach-number flows is then improveed through separate scaling of the velocity- and pressure-difference terms. It is demonstrated that the resulting schemes are capable of robustly and accurately capturing phenomena involving shock and phase discontinuities and interactions between them for numerous two-phase problems. Finally, numerical simulations of cryogenic cavitation and three-dimensional cavitating flows around the Korea Aerospace Research Institute turbopump are presented to confirm accurate and robust behavior of the proposed approaches in computations of multiphase real fluid flows at all speeds.