HLLC-type methods for compressible two-phase flow in ducts with discontinuous area changes

• We develop HLLC-type schemes for flow in ducts of variable cross-sectional area. The are developed general equations state. For two-phase simulations, the homogeneous equilibrium model is employed. tested on Riemann problems ideal gas and CO 2 . Including non-conservative term solver wave structure most robust. In this work, Harten-Lax-van Leer Contact (HLLC) approximate extended to through with discontinuous cross-sections. Two main strategies explored regarding treatment arising governing equations. first, labelled HLLC+S, discretized separately. second, HLLCS, incorporated solver. methods assessed by numerical tests single , latter employing a where thermodynamic properties calculated using Peng–Robinson equation have different strengths, but general, HLLCS found work best. particular, it demonstrated be equally accurate more robust than existing non-resonant flow. It also well-balanced subsonic sense that conserves steady-state