正向风下航母甲板风涡流场的模拟研究

Simulation Study of Vortex Flow in Wind Over Deck of Aircraft Carrier Under the Condition of Head-on Wind

在低马赫数气流条件下,依据运动控制方程组,利用模拟方法,研究航母甲板风涡流场在正向来风时的特点。航母甲板的前部上方压强随着时间变化的规律基本相同;后部甲板上方压强尽管其时均值接近,但距舰艉越近,变化幅度与周期越大。靠近舰艉区域,每隔一段时间出现与舰艏部分周期接近的压强平稳变化,然后出现一段变化幅度较大、周期较长的剧烈压强变化。前部甲板左右两舷诱导出了两个涡,距舰艏越远,涡的强度越小。后部甲板左舷处的涡非常弱,右舷则产生了一个又高又大的涡,并在涡右侧产生了非常明显的下洗速度区域,距舰艉越近,该涡的强度和下洗速度越小。在舰后横向垂直截面上存在着6个涡,艏艉对称面附近3个,左侧区域1个,右侧区域2个(上下分布)。艏艉对称面附近这3个涡高度较低,对直升机起降影响不大,而另外3个涡高度较大,会有较大的影响。

The control equations with the hypothesis of low Mach air flow and the large eddy simulation method of turbulent flows are used to study the characteristics of vortex in the wind over deck of aircraft carriers under the condition of head-on wind.The time-averaged value,the variety period and the variety range of the pressures in the region over former deck are basically same.The time-averaged pressures in the region over tail deck are approached,but the variety period and the variety scope of pressures is lager when the position is more close the stern.In the region near the stern,there a gentle change phase of pressure with the period close the value for pressure at former deck every other time is appeared,then here an acutely change phase of pressure with the high⁃er extent and the longer period is appeared.Two vortexes are induced at the larboard and the starboard of aircraft carrier in the for⁃mer deck.The farther fom the bow,the smaller the vortex intensity.The vortex at the larboard is very puny.There is a high and strong vortex at the starboard and a distinct down-wash region is formed at the right side of the vortex.The farther the vortex is from stern,the smaller the vortex strength and downwash speed are.There are six vortexes in the heel of aircraft carrier,among them three is near the bow-stern plane,one is left side and other two is right side.Since the position of vortex close to the bow-stern plane is lower,which have little effect to the takeoff and land of helicopter.Other three vortexes affect distinctly the operation of heli⁃copter because of their higher position.