面向网衣清洗的内壁-中心体空化喷嘴数值模拟

为提高空化水射流清洗网衣表面的能力，设计了一种内壁-中心体空化喷嘴。采用空化喷嘴空化流CFD数值方法，对比分析仿真与理论解，验证了基于两方程湍流模型的二维轴对称空化流数值模型的可靠性。开展了淹没水射流环境下的内壁-中心体空化喷嘴空化流数值计算，获取了内壁空化器与中心体对喷嘴空化效果的影响，并计算讨论了水深对空化效果的影响。结果表明：水射流通过喷嘴喉部时，分别在内壁空化器及中心体表面产生空泡；中心体空化效果较内壁空化器更好，但对射流阻塞作用更强；内壁空化器会提高喷嘴喉部压强，进一步提高中心体空化效果；内壁空化器与中心体均可降低喷嘴空化效果对水深的敏感度；本研究可为养殖网箱网衣清洗喷嘴设计提供空化流动力学机理研究基础，并提供了低成本、高效率的设计方法。

Numerical simulation of inner wall-central body cavitation nozzle for net cleaning

In order to improve the ability of cavitation water jet to clean the surface of the net, an Inner wall-Central body cavitation nozzle is designed. The numerical method of cavitation nozzle cavitation flow CFD is used to compare and analyze the simulation and theoretical solution, and the reliability of the two-dimensional axisymmetric cavitation flow numerical model based on the two-equation turbulence model is verified. The numerical calculation of the cavitation flow of the Inner wall-Central body cavitation nozzle in the environment of submerged water jet was carried out, and the influence of the Inner wall cavitator and the Central body on the cavitation effect of the nozzle was obtained, and the influence of water depth on the cavitation effect was calculated and discussed. The results show that: The water jet passes through the nozzle throat, creating cavitations on the surface of the Inner wall cavitator and the Central body, respectively; The Central body cavitation effect is better than that of the Inner wall cavitation, but the effect on jet blockage is stronger; The Inner wall cavitator increases the nozzle throat pressure and further improve the cavitation effect of the Central body; Both the Inner wall cavitator and the Center body can reduce the sensitivity of the nozzle cavitation effect to water depth; This study provides a basis for the research of cavitation flow dynamics mechanism for nozzle design of net cleaning in aquaculture cages, and provides design ideas with low cost and high efficiency.