Numerical Calculation of Acoustic Radiation Force and Torque Acting on Rigid Non-spherical Particles

In this study, we have developed a three-dimensional boundary element model for calculating both acoustic radiation force and torque on rigid particles in an inviscid fluid without limitations on particle size, shape, and orientation with respect to the incident wave. Acoustic radiation force and torque acting on three different shapes (spheroid, cylinder with hemispherical cap, and tri-axial ellipsoid) were calculated for different orientation angles with respect to the incident wave. The results show that a rigid non-spherical particle experiences the largest radiation force when it is in its stable angular position. Furthermore, the calculated force and torque were compared with those on sphere and spheroid of equal volume. Such comparison results shed light on the accuracy of using sphere-formulas in approximating the radiation force On non-spherical particles/cells in the real-life experiments.