Analysis of supercavitating and surface-piercing propeller flows via BEM

摘要

A low-order potential based 3-D boundary element method (BEM) is presented for the analysis of unsteady sheet cavitation on supercavitating and surface-piercing propellers. The method has been developed in the past for the prediction of unsteady sheet cavitation for conventional propellers. To allow for the treatment of supercavitating propellers, the method is extended to model the separated flow behind trailing edge with non-zero thickness. For surface-piercing propellers, the negative image method is used, which applies the linearized free surface boundary condition with the infinite Froude number assumption. The method is shown to converge quickly with grid size and time step size. The predicted cavity planforms and propeller loadings also compare well with experimental observations and measurements.