基于CFD和直接计算技术的航行器阻力系数算法研究

A study on hydrodynamic drag coefficients of underwater vehicles based on CFD and direct calculation methods

为了准确计算水下航行器阻力系数,实现水下航行器操纵性能预报和运动控制,以某型水下航行器为例,开展了基于CFD数值模拟计算和理论直接计算的水动力阻力系数算法研究工作。首先在建立水下航行器主尺度物理模型的基础上,运用CFD建立航行器简化模型并划分网格,然后计算此模型在3个平动方向上不同航速时所受的力,进而拟合出阻力系数;其次运用理论公式直接计算航行器阻力系数;最后通过对比分析,验证了2种方法的有效性,并采取均方融合技术以提高计算结果的可靠性。

Accurate calculation of hydrodynamic drag coefficients was the foundation to predict the maneuverability and perform motion control of underwater vehicles in practical applications. The numerical CFD and the direct theory methods on calculating the hydrodynamic drag coefficients were studied in this paper. By using the CFD method, the fluid domain mesh was developed based on the simplified model by considering an underwater vehicle prototype as an example. Meanwhile, the boundary condition was set in order to analyze the force and torque of the underwater vehicle at different speeds in three translational directions. In addition, the drag coefficients were fitted through the calculated force and torque data. The theoretical formula was also applied to directly calculate the drag coefficients. Also, two calculation methods were validated by comparing the results with the refer- ence value of the vehicle prototype. The mean square fusion technique was adopted to take advantages of both methods to improve the calculation reliability of hydrodynamic drag coefficients.