Experimental Study On The Interference Between Cavitation Bubble And Particles

Cavitation phenomenon is easy to occur during the operation of hydraulic machinery such as pumps and turbines.When the flow field contains sediment particles,the synergistic effect of cavitation bubble-particles will cause serious damage to the structure of the equipment.To better reveal the mechanism of the mutual interference of bubble-particles,with the help of high-speed photography technology,this paper conducts experimental research on the mutual interference of cavitation bubble with single particles,symmetric double particles,and asymmetric double particles.The main research contents are as follows:(1)We built a bubble-particle interaction experiment platform to carry out experiments.The cavitation bubble generator device was dsigned to generate bubbles,which controled the size of bubble by adjusting the power supply voltage.Meanwhile,we used the high-speed camera to record the entire process of cavitation bubble-particle interference,and then the image processing software was applied to process and analyze the morphology of bubble and the motion of particles.(2)Study on the interference between cavitation bubble and single particles.The interaction between the cavitation bubble and the particles is analyzed,according to the parameters such as the radius ratio and the dimensionless distance of the particle and bubble.It is found that the maximum horizontal displacement of the particles decreases with the increase of the dimensionless distance.The particle bubble radius ratio does not affect the basic motion pattern of the particles,but it will affect the maximum horizontal displacement of the particles.The cavitation bubble will be deformed by the presence of particles and show different collapse forms at different dimensionless distances,whose collapse time decreases with the increase of the dimensionless distance and eventually approaches the collapse time of the bubble in the free domain situation.(3)Study on the interference between cavitation bubble and double particles.The work analyzed the effects of different particle bubble radius ratios,the dimensionless distance between particles and bubble and the symmetry of particle distribution on the mutual interference process between bubble and particles.The study found that when the cavitation bubble was in the case of symmetric double particles,no deformation occurred and the motion of the particles also exhibited symmetry.In the state of the particles being pushed away,the displacement of the two particles is smaller than that of the single particle.When the cavitation bubble is in the case of asymmetric double particles,the deformation occurs and the collapse time of the bubble was longer than that of the case of the symmetric double particles.And at a specific dimensionless distance,a collapsing jet directed to large particles was generated,which resulted in greater displacement of large particles.But the displacement is smaller than that of single particles under the same conditions.