滑行艇升沉纵摇运动的二维数值预报

Numerical Prediction and Analysis on the Heave and Pitch Motion of Two Dimensional Planning Boat

基于CFD软件对滑行艇二维简化模型在均匀来流中的运动响应进行数值分析。根据滑行艇的流体动力数值计算结果实时求解滑行艇的运动响应特性,对4种不同傅汝德数下滑行艇的纵摇与垂荡耦合运动特性进行研究,得到艇体升沉幅值、纵摇角随时间的变化特性,以及阻力、升力和力矩随傅汝德数的变化规律,并分析了艇体达到稳定状态所需时间和滑行过程中艇底动压力的变化特性。研究表明:傅汝德数1.5时达到稳定滑行状态的时间仅为80 s;除了在傅汝德数2.0时发生严重振荡,其余3种情况下滑行艇均能够趋于一种"动平衡"状态。

The analytical solution for analyzing motion responses of the two dimensional planning boat in the uniform flow is presented by the CFD software.The results of the fluid dynamics are used to derive the motion responses of the planning boat.Numerical simulations of the pitch and heave coupled motion were performed under four different Froude numbers.The characteristics of magnitude of the heave and trim angle varying with the time,as well as the law of resistance,lift and moment changeing with the Froude numbers were derived.In addition,the period of the stable state when the planning boat can be reached and the dynamic pressure at the bottom of the planning boat when in sliding condition were also analyzed.Results show that the time needed for reaching the stable state need only 80 seconds under Froude number 1.5,and the planning boat will tend to be in a ＂dynamic-balance＂ state except for the serious oscillation under Froude number 2.0.