Fundamentals of cavitation and bubble dynamics with engineering applications

Cavitation and bubble dynamics are important topics of fluid mechanics. Generally, cavitation phenomenon plays a negative role in the hydraulic machineries (e.g. hydroturbines, pumps, space engines, and marine propellers) through various kinds of mechanisms. First, the cavitation could cause serious damage on the surfaces of the materials (e.g. patterned erosions with pits) during its final collapse near the boundary. Second, flow inside/outside the machines will be further deteriorated by the vortices generated by the cavitating flows. Third, significant unstable flow could persist for a long time due to the generation of cavitation. As a result, both the efficiency and stable operation of the machines will be challenged by the cavitation.

With a focus on the fundamentals of cavitation phenomenon involved in the engineering practices, this special collection includes several selected findings on the recent developments of the cavitation research. Here, only a brief comment on several selected papers in this special collection will be given for readers’ convenience. In Zhang et al., ¹ unsteady cloud cavitating flow was investigated with the air injection. With the aid of the high-speed camera and pressure measurement, they found that the cavity collapse could be significantly suppressed by the air injections. In Ju et al., ² cavitation in the automotive torque converter was numerically investigated using a well-known homogeneous cavitation model with experimental validations. In Si et al., ³ performances of jetting equipment were experimentally and numerically evaluated with its influences on the characteristics of centrifugal pumps. Cavitation performance of the pumps was tested along with other important characteristics.

Finally, we sincerely hope that readers could benefit from those papers included in this special collection.