半悬挂舵空化及其对非定常力的影响研究

Study on cavitation of semi-supended rudder and its influence on unsteady force

为深入研究空化后半悬挂舵非定常水动力性能的相关规律,采用结构化网格、DES湍流模型和VOF方法对某大型舰船的半悬挂舵空泡进行计算。探讨和分析舵空泡的周期性变化,同时简要分析半悬挂舵的间隙空化及端部空化产生的原因。基于空化和非空化2种状态对3个不同舵角下的舵空泡进行计算,总结了舵横向力、舵轴扭矩等非定常力的规律。结果表明:当空化区域较小时,空化对舵非定常力几乎没有影响,随着空化区域的增大,舵效显著降低;空化发生后,舵非定常力的脉动幅值将急剧增大,且空化区域越大,舵非定常力的脉动幅值越大。该研究结果可为评估空化状态下半悬挂舵的水动力性能及对舵进行优化设计提供技术支撑。

In order to thoroughly investigate the laws related to the unsteady hydrodynamic performance of the semisuspended rudder after cavitation,the structured grid,DES turbulence model and VOF method are used to calculate the semisuspended rudder vacuoles of a large ship.The periodic variation of rudder cavitation is discussed and analyzed,and the causes of gap cavitation and end cavitation of the semi-suspended rudder are also briefly analyzed.Based on the two states of cavitation and non-cavitation,the rudder vacuoles are calculated for three different rudder angles,and the laws of non-constant forces such as rudder transverse force and rudder shaft torque are summarized.The results show that cavitation has almost no effect on rudder non-constant forces when the cavitation area is small,and the rudder efficiency decreases significantly as the cavitation area increases;the pulsation amplitude of rudder non-constant forces will increase sharply after cavitation occurs,and the larger the cavitation area is,the larger the pulsation amplitude of rudder non-constant forces is.The results of this study can provide technical support to evaluate the hydrodynamic performance of semi-suspended rudders under cavitation and to optimize the rudder design.