Abstract:
Previous studies on the acoustic radiation force exerted by focused acoustic fields on spherical particles within pipes have been confined to theoretical and numerical simulations, limiting practical applications. In this study, a quantitative measurement system for determining the acoustic radiation force exerted by a focused acoustic field on spherical particles within a pipe is designed, based on the principle of pure rolling dynamics and high-speed imaging technology. The acceleration of Polyoxymethylene spheres within a fluid-filled acrylic pipe is analyzed using high-speed photography. Combined with pure rolling dynamics theory, the acoustic radiation force is calculated, enabling the direct measurement of acoustic radiation forces in pipes. The experiment found that the acoustic radiation force under the action of focused sound waves in a restricted pipeline exhibits oscillatory characteristics with the radius of the pipe and the radius of the sphere. This oscillation arises from the acoustic resonance effects of the fluid-filled pipe. Simulation and experimental results clarify the influence mechanisms of pipe wall geometry, spherical particle size, and acoustic field intensity on the radiation force experienced by particles in pipes.