潜体近水面垂直面稳定性

基于潜体近水面航行时,作用在潜体上的力以及稳定性等运动性能与大潜深时不同,导出了判断潜体近水面航行时垂直面动稳定性的四阶特征方程,并对四阶特征方程与大潜深状态下用于稳定性分析的三阶特征方程进行了计算.结果表明,潜体近水面航行时稳定性会变坏甚至变得不稳定,用三阶特征方程进行潜体近水面动稳定性分析是欠妥的.对两种初始平衡状态(无纵倾和有纵倾)下的动稳定性进行了计算和比较.对控制稳定性进行了讨论,发现纵倾角控制是使潜体近水面稳定的一种简单而有效的方法.

Stability of a Submersible in Vertical Plane near Free Surface

When a submersible runs near the free surface, the forces acting on it and its motion performances such as stability are different from those in the condition of deep submergence. A fourth order characteristic equation for a submersible running near the free surface which can analyse the dynamic stability in the vertical plane was derived. The calculations were conducted of the fourth order characteristic equation and the third order characteristic equation used for the stability analysis in the condition of deep submergence. The calculation results show that the submersible becomes worse in the dynamic stability or even unstable. The third order equation is unsuitable for the stability analysis of the submersible near the free surface. Besides, the dynamic stability in two initial equilibrium conditions (on even keel and in trim) were calculated and compared. Finally, the control stability was discussed and it was found out that trim angle control is a simple and effective method to make the submersible stable near the free surface.