Abstract:Based on the single chamber self-oscillating pulse nozzle, a dual chamber self-oscillating pulse nozzle was designed by adding an additional singlechamber nozzle in series. The cavitating jet flow in the dual chamber nozzle was simulated in Fluent in terms of the RNG k-ε turbulence model to clarify effects of the nozzle geometrical parameters on the cavitating jet flow field.The influences of Reynolds number, chamber length ratio and diameter ratio on the cavitating jet were analyzed with the liquid vo-lume fraction in the chamber and the velocity at the nozzle exit.The numerical results show that when the Reynolds number rises to 4.31×105 from 2.98×105, the cavitation extent in the chamber increases first and then decreases, and the corresponding liquid volume fraction first decreases and then increases.When the chamber length ratio is 0.67, the airbag in the chamber presents a regular shape and is with symmetrical vortex ring structure, which facilitates the occurrence of pulse cavitating jets.When the chamber diameter ratio is 1.20, both the vortex ring structure and the airbag in the chamber are symmetrical and promote the onset of pulse cavitating jets, but also the velocity at the nozzle exit is more uniform and higher.