舰船空气流场数值模拟及特性分析

Numerical Simulation and Characteristic Analysis of Ship's Air Flow Field

应用计算流体力学技术对舰船空气流场进行数值模拟,对比了求解雷诺平均Navier-Stokes方程(RANS)与分离涡模拟(DES)的结果,总结了2种方法在舰船流场模拟中的特点。结果表明,舰船空气流场呈现出非稳态特征,基于RANS的数值模拟精度不足,而DES方法能够较为准确地捕捉流场中涡的生成和脱落,且与实验符合较好。接着采用DES方法对航母空气流场进行模拟,对比了不同风向下流场中的涡流特征及其对舰载机进舰轨迹上速度分布的影响。发现航母舰岛、甲板等钝体边缘产生相互干扰的复杂涡系,其导致舰载机进舰轨迹上产生强烈的速度波动,这种波动主要集中在航母后部甲板及邻近的尾流区,且随着时间的推进而变化,呈现一定的周期性。

The air flow field of ship was simulated by using computational fluid dynamics technology to analyze its prime characteristics with reasonable accuracy. The different results of Reynolds-Averaged Navier-Stokes( RANS)method and Detached Eddy Simulation( DES) were compared,and the calculation traits of these methods were discussed. The results show that the air flow field of ship is unsteady. The accuracy of RANS simulation is insufficient for capturing this unsteady phenomenon. However,DES can catch this with better accuracy and expresses a comparatively great conformity with experimental data. Then,the aircraft carrier’s flow field was calculated by DES.The characteristics of vortexes and velocity fluctuation on the ideal landing track were discussed in different wind directions. Those simulations indicate that there are complicated vortexes produced by blunt edges of the island and deck in the flow field. Those vortexes interact and mainly exist in the rear of flight deck and its adjacent air wake.Moreover,they cause a conspicuous and periodical velocity fluctuation on the ideal landing track as time goes on.