A sharp-interface immersed smoothed point interpolation method with improved mass conservation for fluid-structure interaction problems

To solve the problem of inaccurate boundary identification and to eliminate the spurious pressure oscillation in the previously developed immersed smoothed point interpolation method (IS-PIM), a new sharp-interface IS-PIM combining mass conservation algorithm, called Sharp-ISPIM-Mass, is proposed in this work. Based on the so called sharp-interface method, the technique of quadratic local velocity reconstruction has been developed by combining with the mass conservation algorithm, which enables the present method improve the accuracy of the velocity field and satisfy the mass conservation condition near the boundary field. So the proposed method would not encounter the problem of spurious mass flux. In addition, a new form of FSI force evaluation considering pressure and viscous force to perform a whole function from the fluid domain to fictitious fluid domain is introduced, which makes the present method obtain more accurate results of FSI force than the original one. Through the numerical studies of a number of benchmark examples, the performance of the Sharp-ISPIM-Mass has been examined and illustrated.