Investigation of self-excited oscillation chamber cavitation effect with special emphasis on wall shape

Analysis of the self-excited oscillating jet nozzle makes it possible to investigate the influence of structural and geometric shapes on the effect of self-excited oscillation cavitation and energy efficiency. In this paper, a new self-excited oscillation chamber structure was obtained using a Bezier curve to reconstruct the wall transition surface, and the cavitation airbag energy concentration was maximized to efficiently utilize the pulse energy. Numerical analysis and simulation were used to study the turbulent kinetic energy, steam volume fraction, and vortex growth cycle of the outlet. The results showed that the novel chamber wall structure weakens the interior secondary vortex in the self-excited oscillation chamber and forms a large cavitation airbag area and reduces energy dissipation. In addition, using the new chamber with redesigned wall structure, the peak turbulent kinetic energy, the velocity at the jet exit, and the vapor volume fraction inside the chamber increased approximately 10.3%, 14.6%, and 9.1%, respectively.