Cavitation damage characteristics following marine fouling cleaning by a self-excited oscillation cavitation waterjet

Abstract

Marine fouling attached to the hull of a ship will reduce its economic performance and therefore regular cleaning is required. Cavitation jets are a widely used and effective cleaning method for removing marine fouling. In this study, an orthogonal experiment was conducted to investigate marine fouling cleaning using a self-excited oscillation cavitation waterjet by simulating the adhesion of marine fouling to the hull. The significance of the incident angle θ, jet pressure P, and standoff distance R on the damage area and surface roughness were studied, and the damage caused by the cavitation waterjet was analyzed by scanning electron microscopy (SEM). It was found that, a) Damage to the surface of samples was minimized by spraying at a 90° incident angle and ensuring a 16 MPa jet pressure with a 25 mm standoff distance. b) The jet impact zone had the most severe damage, with samples displaying two forms of damage: fatigue failure and plastic deformation under the action of the cavitation waterjet. The results of this study provide a theoretical basis and parameter guidance for optimizing marine fouling cleaning.