Design and Test of a Cavitation Water Jet Net Box Cleaning Device Based on Ansys Fluent

This study addresses the issue of biofouling on marine aquaculture cages, where organisms like algae and purple mussels negatively impact both the safety of the aquaculture environment and the integrity of the cages. To solve this problem, the paper introduces a cage cleaning device based on the cavitation jet principle. Using finite volume simulation software, the cavitation process of the device’s nozzle was modeled, with the gas-phase volume fraction used as the evaluation metric. Key experimental factors, such as the second section throat contraction angle, second section throat radius, and end diffusion angle, were analyzed through single-factor and quadratic regression orthogonal experiments to assess their effect on the cavitation performance. The optimal combination of nozzle parameters was determined to be a second section throat contraction angle of 41.047°, a second section throat radius of 0.834 mm, and an end diffusion angle of 35.495°. Under these conditions, the gas-phase volume fraction reached 0.941, indicating optimal cavitation performance. To validate these findings and further optimize the nozzle’s operational parameters, a nozzle cavitation test bench was constructed. Test results demonstrated that when the target distance was set at 15 mm and the angle at 20°, the surface roughness and maximum surface depth of the target were 6.215 μm and 22.030 μm, respectively, with the nozzle exhibiting the best cavitation effect at these settings. This nozzle design meets the requirements for efficient mesh cleaning, and the research provides valuable insights for future development and optimization of cleaning devices for aquaculture net cages.