Convective schemes for capturing interfaces of free-surface flows on unstructured grids

In this article, the general methodology used in constructing interface-capturing schemes is clarified and concisely described. Moreover, a new interface-capturing scheme, denoted S TA CS and based on a switching strategy, is developed. The accuracy of the new scheme is compared to the well-known CICSAM and HRIC schemes by solving four pure advection test problems. Results, displayed in the form of interface contours for the various schemes, reveal deterioration in the accuracy of the CICSAM and HRIC schemes, with their performance approaching that of the UPWIND scheme as the Courant number increases. On the other hand, predictions obtained with the new STACS scheme are by far more accurate and less diffusive, preserving interface sharpness and boundedness at all Courant number values considered.