浸深比对半浸桨水动力特性影响的数值分析

Numerical analysis of the influence of immersion ratio on the hydrodynamic characteristics of surface piercing propeller

为了分析自然通气状态下浸深比对半浸桨水动力特性的影响,通过求解RANS方程模拟标准模型841B的流场同时结合VOF方法和滑移网格技术建立了可靠的数值方法,并应用该方法研究了不同浸深下SPP-1桨的水动力特性。分析了不同浸深下半浸桨的敞水性能、力的脉动特性以及尾流场特性。研究结果表明:半浸桨的通气状态与浸深比、进速系数密切相关。在非全浸工况下,推力和扭矩均是随进速增加先增加后减小;全浸工况下与常规桨类似。浸深与通气状态对半浸桨受力的脉动特性影响很大。浸深增加,尾流场更加均匀。尾流场中速度分布在自由液面处发生突变。

To analyze the influence of immersion ratios on the hydrodynamic performance of surface piercing propellers under natural ventilation, a reliable numerical method was established. The numerical simulation of the standard 841B model was performed by solving the RANS equation and combining it with the VOF method and sliding mesh technique. The hydrodynamic characteristics of an actual surface piercing propeller （SPP-1） at different immersions were investigated using this method. The open water performance, force pulsation, and wake flow field characteristics of SPP-1 under different immersions were analyzed. The results showed that the ventilation states of SSP-1 were closely related to the immersion ratio and advance speed coefficient. When the SSP-1 was not fully im- mersed, the thrust and torque first increased and then decreased along with the increase in the advance speed coef- ficient. Under the fully immersion condition, the change in trends of the hydrodynamic coefficients was similar to that of conventional propellers. The immersion depth and ventilation states had great influence on the pulsation characteristics of the forces/moments of SSP-1. The wake flow field was more uniform as the immersion depth increased, whereas the velocity distribution in the wake flow field mutated in the free surface.