FORCE ACTING ON A PARTICLE AND A BUBBLE IN A SPHERICALLY OSCILLATING INVISCID LIQUID.

The force acting on a particle and a bubble in a spherically oscillating inviscid liquid is computed and proved to be directed toward the center of the spherical motion. The theoretical solution is analytic for rigid particles and partly numerical for gas bubbles. Results show that under appropriate conditions this force is of the order of magnitude or greater than the gravity force, and it is greater for bubbles than for rigid particles. The use of this phenomenon as a means of separation and controlling particle motion in both gravitational and nongravitational fields is suggested.