扭曲舵空化起始航速分析

Analysis on the cavitation inception speed of a twisted rudder

针对水面中高速舰船舵的空化问题,研究了普通舵和扭曲舵的空化特性,比较了两种舵的空化起始航速。通过CFD方法,对桨后舵水动力性能进行了数值计算,得到普通舵和扭曲舵的在各种工况、各种舵角条件下的压力分布特性,通过考查两种舵的压力分布特性,对普通舵和扭曲舵的空化起始航速进行了计算评估。结果显示:在各航速各舵角下,扭曲舵的压力降峰值比普通舵明显减小,可以大幅提高舵的空化起始航速,在舰船0舵角直航时,扭曲舵的空化起始航速可以提高5.9 kn。因此扭曲舵可以减小舵上空化剥蚀和振动,对舵的使用寿命和舰船的隐身性是有利的。

Aimed at the rudder cavitation problem of high-to-middle speed surface ships, the cavitation characteristics of twisted and ordinary rudders were studied, and the inception speed of rudder cavitation is compared between the two rudders. The hydrodynamics of rudder behind a propeller was numerically calculated. The pressure distribution characteristics of the twisted and ordinary rudders were compared with each other under different working and rudder conditions. The inception speed of cavitation was calculated and evaluated by investigating pressure distribution char-acteristics of the twisted and ordinary rudders. It indicates that under different speeds and angles of the rudder, the peak of pressure fall on the twisted rudder is much lower than that on the ordinary rudder, which can significantly in-crease the inception speed of rudder cavitation. The cavitation inception speed of a twisted rudder can increase 5.9 kn at 0 rudder angle. As a result, twisted rudders can reduce the cavitation erosion and vibration on the rudder, which is favorable to the service life of a rudder and the stealth of ships.