Characteristics of Impinging Water Jet Discharged From a Central-Body Nozzle

Submerged water jet discharged from a central-body nozzle was investigated through flow visualization, numerical simulation and impingement experiment. Under jet pressure of 15 MPa, three layout plans of central body were introduced and corresponding water jets were visualized by using high speed photography technique. Cavitating jet flow fields were simulated with commercial computational fluid dynamics (CFD) software Fluent which employs full cavitation model. Sandstone cuboid was used as the sample workpiece exposed to the submerged water jet of 15MPa. It is proved that cavitation tone exist in the wake flow after the central body. When the end cross-section of the central body is parallel with the nozzle outlet section, the largest axial length of cavitation zone is obtained. Compared with round water jet with the same equivalent nozzle outlet area, the central-body nozzle yields stronger impinging effect.