Drag reduction mechanisms and cavitation inhibition effect of coupling bionic design on pressure relief valve

Abstract

Cavitation significantly influences the performance of pressure relief valve, and bionic theory offers a promising solution to this challenge. Inspired by the surface morphology of shark skin and lotus leaf, two novel bionic anti-cavitation valve cores are proposed: a unit and a coupling bionic structure. The cavitation and flow resistance inside different bionic valve core structures are investigated experimentally and numerically. The relationship between cavitation, vortices, and flow resistance is also discussed. The results show that cavitation inside the pressure relief valve is influenced by the inlet pressure, a higher inlet pressure leads to more severe cavitation. Compared with traditional smooth valve core, the unit and coupling bionic valve core structures are helpful to inhibit cavitation development. Specifically, the cavitation development lengths of the unit and coupling bionic valve core structures are reduced by 31.03 % and 34.48 %, respectively. In terms of reducing flow resistance, the bionic valve core enhances fluid flow by weakening the strength of axial vortices and reducing flow resistance. Among them, the coupling bionic valve core shows the best performance, with a cavitation inhibition effect and lower fluid resistance. The maximum drag reduction rate achieved by the coupling structure is 45.92 %.