桨后舵片空化的面元法数值计算方法

Numerical investigation of sheet cavitation of rudder behind propeller by surface-panel method

舵空化不仅会对舵叶产生剥蚀作用,而且还会引起船体艉部振动和噪声增大,针对舵的空化问题,建立了桨后舵片空泡的面元法数值计算方法。通过面元法对螺旋桨的水动力性能计算得到了螺旋桨表面及尾流面的奇点强度,进而得到螺旋桨的尾流场,以此作为舵的来流输入条件,再通过基于速度势的面元法对舵上的片空泡进行计算,最终得到舵片泡的范围和厚度分布。通过该方法,研究了某型船的桨后舵在各航速各舵角的片空化形状,分析了各舵角时舵的空化起始航速,形成了舵空泡的快速计算方法,该方法可以在舰船设计阶段对舵的空泡性能进行评估,为舵的优化设计提供技术支撑。

According to the problems caused by rudder cavitation, a surface-panel method calculating the cavitation of a rudder behind the propeller was set up. The hydrodynamic performance of the propeller was calculated and, thus, the singularity strength on the propeller surface and wake surface was obtained. Then, the wake field of the propeller was calculated, and used as the inflow condition for rudder cavitation. The cavitation shape, including the range and thickness of the rudder, was calculated by the surface-panel method based on the velocity potential. The cavitation shape of a ship＇s rudder was investigated at different rudder angles and under different speed conditions by the pro- posed method. The speed of cavitation inception was analyzed under different conditions. A quick method for calcu- lating rudder cavitation was set up. This method can provide technical support to the optimization of rudder design.