船体、定子与导管相互干扰尾流特性的数值模拟与试验验证研究

Numerical simulation and experimental validation on the wake flow field characteristics of hull/stator/duct interaction

文章通过求解RANS方程,结合雷诺应力模型,数值模拟了水下航行体模型Sub A在不带导管、定子与带导管、定子两种不同状态下的尾流三向速度场,分析了船体、定子与导管相互干扰尾流特性,数值模拟给出了模型尾部不同半径上的三向速度与伴流分数,并与试验结果进行了对比分析,两者结果吻合得很好,研究表明文中所使用的数值计算方法可以有效地模拟尾部三向速度场。通过对比发现,定子与导管对尾流场有阻滞作用,且相互干扰尾流特性相当复杂。同时利用数值模拟方法探讨了尾部去流段长径比对尾流场的影响,计算了两种不同长径比回转体模型的尾部去流段边界层速度分布,详细分析了尾部外法线上速度分布和边界层厚度随长径比的变化,指出该模型尾部去流段相对短粗肥胖,导致逆压梯度相对较大且变化剧烈,从而导致边界层增厚,速度相对降低,卷吸携带作用减弱,最终桨盘面轴向速度分布产生相应变化。

The 3-dimensional wake flow field around an underwater vehicle without stator/duct and with stator/duct was numerically simulated by solving RANS equations with Reynolds stress model to analyze the hull/stator/duct interaction. The computational results of the 3-dimensional velocity in different radius in the propeller disk were presented. By comparing with the experimental results, the computational results agreed well with measured data, it is shown that the numerical method in this paper could be used to simulate the 3-dimensional wake flow field. Based on the computational results, the stator and duct would retard the wake flow field, and the hull/stator/duct interaction was so complicated. Then numerical simulation for two models with different length-to-diameter factors was done to find the influence on the wake flow.With the results of velocity distribution and boundary layer thickness, it was shown that the tail section of model Sub A was relatively short and fat, so the adverse pressure gradient was large, which reduced the velocity and weakened the entrainment carrying effect, eventually the axial velocity distribution in the plane of propeller disk was changed.