小水线面船的运动稳定性

Motion Stability of SWATH

SWATH运动稳定性的分析计算在运动方程基础上进行。本文给出小扰动运动方程组。潜体产生的 Munk力矩是导致 SWATH纵向和横向运动稳定与否的重要因素。本文讨论了不带鳍的本体纵向稳定条件 ,以及稳定鳍在增稳和改善运动品质上的作用和优选方法。横倾运动稳定性初步分析时忽略相对高阶小量 Cn,特征方程自然去耦而分解成两个二次方程式 ,便于计算分析。通过目标船的实例分析 ,证明了鳍的作用不单是增稳且能改善运动品质。 Cnβ 是一关键导数 ,直接影响航向稳定性 ,甚至导致横甩。如应用导管螺旋桨将有利于改善稳定性。试验一再表明 :试验结果与计算结果的符合程度让人满意。

The analysis of stability of SWATH rests upon the motion equations. The small-disturbance equations are derived in this paper. The Munk moment of submerged bodies is the cause of instability of motion. The longitudinal motion stability criterion of a body without stablized fin is given, and the effect of the fins is discussed, which not only stabilize the longitudinal motion, but also improve motion quality. The characteristic equation of lateral motion is able to be decoupled while neglecting C nφ , and can be taken apart two quadratic equations which are easy to deal with. Numerical examples for object SWATH confirm the effect of fins on the longitudinal motions, C nβ  is a key derivative, which plays an important role of lateral stability, especially the directional one. A large negative C nβ  may cause instability in direction, using ducted propeller may be favourable. Model tests indicate that coincidence for results of experiments with theoretic prediction is satisfactory.