2019 journal article

An enhanced AUSM(+)-up scheme for high-speed compressible two-phase flows on hybrid grids

SHOCK WAVES, 29(5), 629–649.

co-author countries: United States of America 🇺🇸
author keywords: Two-fluid model; Shock waves; Material interfaces; AUSM
Source: Web Of Science
Added: July 8, 2019

An enhanced $$\hbox {AUSM}^+$$ -up scheme is presented for high-speed compressible two-phase flows using a six-equation two-fluid single-pressure model. Based on the observation that the $$\hbox {AUSM}^+$$ -up flux function does not take into account relative velocity between the two phases and thus is not stable and robust for computation of two-phase flows involving interaction of strong shock waves and material interfaces, the enhancement is in the form of a volume fraction coupling term and a modification of the velocity diffusion term, both proportional to the relative velocity between the two phases. These modifications in the flux function obviate the need to employ the exact Riemann solver, leading to a significantly less expensive yet robust flux scheme. Furthermore, the Tangent of Hyperbola for INterface Capturing (THINC) scheme is used in order to provide a sharp resolution for material interfaces. A number of benchmark test cases are presented to assess the performance and robustness of the enhanced $$\hbox {AUSM}^+$$ -up scheme for compressible two-phase flows on hybrid unstructured grids. The numerical experiments demonstrate that the enhanced $$\hbox {AUSM}^+$$ -up scheme along with THINC scheme can efficiently compute high-speed two-fluid flows such as shock–bubble interactions, while accurately capturing material interfaces.