水下结构体俯仰运动对其水压场影响的数值分析

Numerical analysis of the influence of underwater structure pitching motion on its hydrodynamic pressure field

为研究水下结构体俯仰与平动耦合运动对其水压场的影响,利用势流理论分析结构体耦合运动的水压场,并借助重叠网格技术分别对结构体在平动、存在攻角的平动、俯仰运动、俯仰平动耦合四种运动状态下的水压场进行分析。以不同轴长比的椭圆型结构为研究对象,分析不同振荡角速度下的水压场。结果表明,椭圆型结构的俯仰运动会使水压场曲线的负压峰随时间变化产生偏移,俯仰振荡的角度越大,负压峰偏移的程度也越大。此外,椭圆型结构的轴长比也会影响曲线的偏移程度。椭圆型结构的俯仰振荡引起的水压场的频谱具有一个甚低频谱峰,该谱峰峰值对应的频率与椭圆型结构振荡的频率一致。

To study the influence of the pitching and translational coupling motion of underwater structure on its hydrodynamic pressure field,the potential flow theory was used to analyze the hydrodynamic pressure field of the coupling motion of the structure.The overlapping grid technology was used to analyze the hydrodynamic pressure field of the structure in the four motion states of translational motion,translational motion with attack angle,pitching motion,and pitching translation coupling.Taking elliptical structures of different axial length ratios as the research object,the hydrodynamic pressure field under different angular velocities was analyzed.The results show that the pitching motion of the elliptical structure will make the negative pressure peak of the hydrodynamic pressure field curve shift with time.The larger the angle of pitching oscillation is,the greater the negative pressure peak shifts.In addition,the axial length ratio of the elliptical structure will also affect the offset degree of the curve.The spectrum of the hydrodynamic pressure field caused by the pitching oscillation of the elliptical structure has a very low frequency spectrum peak.The frequency corresponding to the peak of the spectrum is consistent with that of the elliptical structure oscillation.