Impact pressure distribution of air-ventilated submerged water jets perpendicularly impinging on a circular plate

Flow visualization of air-ventilated submerged water jets was performed using a high-speed video camera under conditions analogous to those of a submerged abrasive suspension jet (ASJ) issued from a nozzle with an air-ventilated sheath. The impact pressure generated by the jet impinging perpendicularly on a circular plate was measured using pressure-sensitive films. The pressure distribution on the plate surface was analyzed to clarify the relationship between the jet’s flow structure and its submerged processing capability. The results revealed that the flow structure varied significantly depending on the ventilation flow rate. At an injection pressure of Pin = 30 MPa, appropriate air ventilation significantly suppressed the impact pressure in the peripheral region while enhancing the pressure at the jet center, clearly demonstrating the effectiveness of air ventilation.