水下航行体通气超空泡减阻特性实验研究

Experimental study of the drag reduction of ventilated supercavity of underwater bodies

为了研究超空泡的减阻效果,保证在较低流速下生成超空泡,在水洞中开展了水下航行体通气超空泡的实验研究.采用通气的方法在较低水速下生成人工通气超空泡,通过改变通气率和弗劳德数,获得了不同条件下通气空泡的长度,以及不同空泡长度下的模型阻力系数.研究表明,来流速度不变时,空泡长度随通气率的增加而增加,阻力系数随空泡长度的增加先递增后递减;空化器直径对阻力系数的影响较大,在大弗劳德数条件下,阻力系数会因空化器直径过大而出现随通气量的增加而变大的趋势.利用商用软件对超空泡形态及阻力系数作了数值仿真,并与实验结果作了对比,两者符合较好.

In order to explore the drag reduction of supercavity and guarantee forming supercavity in lower velocity, experiments of the ventilated supercavity of underwater bodies have been performed in cavitation tunnel. Supercavities have been formed by using the method of ventilation in lower velocity. By changing ventilation volume and Froude number, a series of supercavity lengths have been obtained in different conditions and drag coefficients of model at different cavity lengths are gained. The experimental investigation shows that, at constant velocity, the supercavity length increases with the increase of ventilation volume and the drag coefficient of model increases initially and then begins to reduce with the increase of the cavity length. The cavitator diameter largely influences the drag coefficient which, under the condition of large Froude number, begins to increase with the increase of ventilation rate because of too large cavitator diameter. Numerical simulation of supercavity shape and drag coefficient has been made by using the commercial software, and the results fit well with the experimental results.