弗劳德数对超空泡尾部流体动力修正方法

由于水洞流速较低,受弗劳德数影响,水洞实验条件下空泡形态存在上漂现象,实验得到的运动体尾部流体动力特性也因此受到影响.为了消除弗劳德数对实验结果的影响,得到较为合理的尾部升力曲线,采用有攻角情况下滑行状态时的升力减去零攻角时对应的升力的办法来修正实验结果,采用数值模拟方法证明了此方法的可行性.提出了对应通气率和对应空泡状态两种方法来对应相减.对两种方法的优劣进行了比较.采用此方法修正后的尾部流体动力曲线基本消除弗劳德数影响,曲线较为合理.

Correction of wetted section hydrodynamic character of supercavitated bodies with Froude number

Due to the Froude number is not big enough to eliminate gravity action in water tunnel experiment, the distortion of the supercavity shape will not be avoided. Obviously the hydrodynamic character of the wetted section in experiment is correlated with Froude number, the shape of the supercavity tail floating-up is correlated with experiment Froude number and effects the wetted section size. The purpose of this paper is to describe the relationship of the wetted section hydrodynamic forces with Froude number. To correct the lift coefficient, the eliminating effect method is proved feasible by numerical simulation, the data revised principle is that the lift coefficient at nonzero degree angle of attack subtracts that at zero degree corresponding to the same state. The subtracting for the lift coefficient can be conducted corresponding to similar ventilation rate coefficient or the similar wetted state. The comparison between the two corresponding methods is made. The lift coefficient curve corrected by the method is rational and the Froude number effect has almost been removed.