Surface Protection Strategies for Dome Shaped Structures against Cavitation Erosion

Submarine-launched missiles with domed nose cones are highly vulnerable to cavitation erosion as they travel at high speed through an underwater launch tube and then into the air from the sea surface. The collapse of vapour cavities crystallizes intense damage on the vehicle surfaces so that the vehicle structure and aerodynamic performance are threatened. In this work, we show the full 3D numerical and analytical analysis of surface protection concepts for the reduction of cavitation damage on such an axisymmetric dome-shaped body. A computational methodology was developed by importing a complex computer-aided design (CAD) model of a dome and the connecting tubular structure into a high-fidelity simulation environment. The geometry was simplified by omitting non-essential details to facilitate the generation of quality mesh for CFD analysis. Simulations have been carried out to analyze the flow field and pressure distribution under two critical stages, at two angles of attack of 0° and 12° and different launch depths. This investigation focuses on a passive mitigation technique that bonds an optimised rubber padding to the dome's exterior surface. The impact forces from collapsing cavitation bubbles are thought to be absorbed and dissipated by the rubber due to its viscoelastic nature, leading to a reduction of the impulsive stress on the substrate. The results show that the controlled introduction of such a compliant material dramatically changes the surface response to cavitation implosions. The suggested rubber padding is demonstrated to be an efficient and practicable means of protecting the surface; thus, the risk of cavitation erosion is diminished considerably, and the service life and reliability of the underwater projectile vehicle can be improved.