不同横流攻角时抛弃式探头水动力学特性研究

Hydrodynamic Characteristics Study of Expendable Probe at Multi Cross Flow and Multi Attack Angle

抛弃式探头的下沉运动,主要受横流和攻角影响。采用混合网格结合k-e湍流模型,对下沉运动进行数值计算,分析在5个不同攻角、5个不同横流时的水动力学特性。结果表明:探头在水平方向C_d随横流增大而显著增大,垂直方向C_d增幅较小;探头在水平方向C_d随攻角增大而逐渐增大,45°攻角附近后开始减小,垂直方向C_d则持续增大;设定2 m/s下落时,探头头、尾部力矩不同,使得探头姿态发生改变,最终以一固定攻角匀速下落。可为进一步提高抛弃式探头的下沉数学模型的测深准确度提供依据。

The cross flow and attack angle are the two main influencing factors in the process of expendable probe releasing and sinking. The numerical simulation model is developed based on the hybrid grid and k-？ turbulent model, and the hydrodynamic characteristics of five cross flows and five attack angles are analyzed. The results show that the drag coefficient of the probe in the horizontal direction increases gradually, while the drag coefficient of the probe in the vertical direction increases slowly with the increase of the cross flow. The drag coefficient in the horizontal direction increases gradually with the increase of attack angle and turns to decrease nearby 45°, while the drag coefficient in the vertical direction increases continuously. The drag interpolation between probe head and tail is related with the larger attack angle, with 2 m/s falling speed, which makes the attack angle change, and the probe sinking at a constant speed in a fixed attack angle ultimately. The results can provide evidences to improve the depth measurement accuracy of probe.