螺旋桨空化演变与压力脉动关联机理研究

The unsteady cavitation around propellers is a key important factor for the propeller performance of vibration and noise. And it is an imprtant subject to study the pressure fluctuation induced by cavitating propeller in the area of hydraulic machine. In present project, the methods together with hydrofoil experiment, theoretically analysis and numerical simulation are adopted to reveal the excited pressure by cavitating propeller in non-uniform wake and primary contents are as following: the relationship between cavitating flow evolution and force pulsation as well as pressure fluctuation around a designed twisted hydrofoil is analyzed in detail by experiment; By comparison with experimental results, the interaction of cavitation and turbulence will be investigated based on the SGS model, which will be applied to three dimensional cavitation simulation in hydraulic machine; Based on the work described above, unsteady DES simulation of cavitating flow evolution and induced pressure fluctuation around propeller in non-uniform wake will be carried out; According to vortex dynamics method and bubble dynamics theory, the mechanism of propeller excited pressure fluctuations induced by cavitation is investigated and some engineering methods will be proposed to alleviate the cavitating pressure fluctuations. This project will provide worthy support for analyse of cavitating flow in hydraulic machine and ship industry, which is a key problem in academic and engineering application aspects.

螺旋桨空化演变与其振动和噪声特性密切相关，而螺旋桨空化条件下诱发的压力脉动是水力机械领域的重要学术问题。本课题采用水翼机理实验、理论分析和数值模拟相结合的方法，以揭示螺旋桨在非均匀流条件下的空化与压力脉动关联机理为目标，拟开展的研究内容包括：设计三维扭曲水翼，开展空化机理实验，分析三维水翼空化演变特征、力特性以及典型位置处的压力脉动内在关系；参照实验结果，开展空化与湍流相干机理的高精度SGS模型研究，并详细探究空化脱落与升阻力变化及压力脉动关联机制；在此基础上，开展螺旋桨在非均匀来流条件下的空化流动演变及其诱导的压力脉动高精度DES模拟；基于数值模拟结果，采用涡动力学方法和空泡动力学理论，深入研究螺旋桨上空化诱导的压力脉动激增机理，总结出一些工程上控制空化压力脉动的具体措施和建议。该研究可为解决我国水力机械学科和船舶行业的关键问题提供技术支撑，具有重要的学术价值和工程应用价值。

螺旋桨空化流动及其演变对船舶振动和噪声特性有着根本性的影响，其相关机理的认识和把握对提高军用舰船的隐蔽性，乃至现代高技术要求下的民用船舶具有很现实的意义。本课题采用水翼机理实验、理论分析和数值模拟相结合的方法，开展了非均匀来流条件下螺旋桨非定常空化湍流流动演变及其诱导的压力脉动研究。具体工作如下：在小型多功能空化水洞中开展了水翼空化机理试验，并分别开展了多工况的高速摄影分析；开展了三维水翼的非稳态空化大涡模拟研究，发展了一种可考虑空化湍流相互作用的SGS亚格子应力模型，并成功应用于水翼复杂空化绕流研究之中；开展了空化与漩涡相互作用特性研究，揭示了空化马蹄形结构及对涡运动发展与边界层变化的影响规律；基于课题组在空化湍流数值模拟方面已有的研究成果，成功实现了螺旋桨非均匀来流条件下的复杂空化绕流研究；研究了侧斜对螺旋桨空化压力脉动的影响，基于空泡动力学原理揭示了空化体积二阶导数为螺旋桨上空化压力脉动激增的根源。项目执行期间，发表基金标注论文25篇，其中SCI检索14篇，3篇入选ESI高被引论文(ESI Highly Cited Papers)。通过项目研究，协助培养博士生3人、硕士生2人。