Combined experimental and computational investigation of the cavitating flow in an orifice plate with special emphasis on surrogate-based optimization method

We investigated the influence of geometrical parameters of the orifice plate on the cavitation structures, and optimized these parameters by using a surrogate-based model with special emphasis on the concentration of hydroxyl radical released. The results show that for the orifice plate of the hydrodynamic cavitation system, the possible location of the inception of the cavity spreads to throat and divergent section of the venturi geometry. Based on the surrogate model and global sensitivity assessment, the diameter of throat D_t and diameter of inlet D_in significantly influenced the size of the cavity, while the length of throat L_t had little effect on both cavitation intensity and flow rate. It should be noted that when L_t is decreased, the size of cavity would be slightly decreased but the flow rate increased clearly. The increase of the diverging section is in favor of the size of cavity. By comparing the experimental measurements on the concentration of Methylene blue, the optimum geometry of the orifice plate for best cavitational activity is proposed.