A Modification of the Switch Function in the Elrod Cavitation Algorithm

The implementation of the mass-conservative cavitation algorithm, as derived by Elrod, requires an automatic setting of a binary switch function that delineates the full-film and cavitation zones. Abrupt changes associated with this function often causes convergence and instability issues. A method is that which improves numerical instability and overcomes the convergence issues caused by the conventional binary switch function. Two test cases are presented, which show that by using the new switching algorithm together with a successive over-relaxation solver, the Elrod cavitation algorithm converges up to 61% faster while it is less prone to numerical instabilities.