基于PANS方法的水下热射流数值仿真与试验验证

Numerical simulation and experimental verification of underwater thermal jet based on PANS method

随着水下热射流的浮升,其动量逐渐衰减进而演变为羽流,采用常规的雷诺时均方法进行模拟容易出现涡粘过大导致仿真结果失真的问题。针对这一问题,文中以水下热射流出口为研究对象,运用PANS(Partially-Averaged Navier-Stokes)方法改进了水下热射流的计算模型,对其在静止和运动工况下的浮升扩散过程进行数值模拟,分析了水下热射流的浮升扩散规律。然后搭建了全透明的拖曳式试验水槽,采用平面激光诱导荧光(PLIF)方法测得的热射流在静止和运动工况下的浮升扩散图像与数值仿真结果进行对比验证。结果表明:基于PANS方法的水下热射流预测模型精度较高,所有误差均在15%以内,且绝大部分误差控制在10%以内。

With the rise of the underwater thermal jet,its momentum gradually decays and evolves into a plume.Using the conventional Reynolds-averaged method for simulation is prone to the problem of excessive eddy viscosity leading to the distortion of simulation results.In order to solve this problem,the outlet of an underwater thermal jet as the research object was taken,the calculation model of an underwater thermal jet by using PartiallyAveraged Navier-Stokes(PANS)method was improved,the floating-up and diffusion process under static and moving conditions were simulated,and the floating-up and diffusion law of underwater thermal jet were analyzed.A fully transparent towing tank was built,and the floating-up diffusion images of the thermal jet measured by the PLIF method under static and moving conditions were compared with the numerical simulation results.The results show that the prediction model of underwater thermal jet based on PANS method has high accuracy,all errors are within 15%,and most of the errors are controlled within 10%.