Two-dimensional Modelling of Partial Cavitation with BEM. Analysis of Several Models

The present paper deals with the modelling of steady 2D parti al cavitation on hydrofoils using a Boundary Element Method (BEM) . An extensive analysis is carried out for several models, a non- linear model with the boundary conditions applied on the true cavit y surface and a partially non-linear model with the boundary cond itions applied on the foil surface beneath the cavity. For this seco nd model two variants are considered, one with re-gridding at each it eration step and one without re-gridding. For the non-linear model b a re-entrant jet closure model and a pressure recovery model a implemented. Tests were devised to analyze the relevant featu res of the cavitation phenomenon obtained with the various models . Numerical studies on the convergence behavior, robustness an d CPU time are presented, as well as comparisons between the model s for different foils and loading conditions. The results for there-entrant jet model are compared with other results available in liter ature. Finally, a quality assessment is proposed.