基于ALE方法的飞机水面降落过程

On dynamic structural response of an airplane landing onto water

为了研究飞机水面降落过程中的动态响应规律,采用arbitrary Lagrangian-Eulerian(ALE)方法开展了飞机水面降落的动力学分析。研究了飞机水面降落过程的速度变化规律,结果表明,降落速度和飞行速度在飞机入水的初始阶段变化较快,随后变化幅度趋于平缓。分析了不同降落速度、飞行速度和降落仰角下的机身结构响应,得到了飞机水面降落时结构响应随时间的变化规律。机身结构应力在入水的初始阶段达到最大值,随后迅速下降,最后保持稳定。飞机结构的最大变形也出现在入水的初始阶段,随后迅速回复到初始状态。对比了降落速度、飞行速度和降落仰角对飞机结构响应的影响程度,结果表明降落速度对结构响应的影响程度最大,降落仰角次之,飞行速度的影响最小。

The dynamics of the airplane impacting on water was investigated. The arbitrary Lagrangian-Eulerian （ALE） method was employed to describe this fluid-structure interaction problem. The velocity of the airplane after landing was researched by analyzing the velocities of the airplane head and tail. The head and tail velocities changed rapidly in the initial stage of entering water, and then they kept stable. The structural response of the airplane airframe after landing was explored under different vertical velocities, horizontal velocities and landing elevations. The von Mises stress arrived at the peak value in the initial stage, then it decreased rapidly, finally it stayed steady. The maximal structural deformation was achieved in the hundreds milliseconds after landing, and then it relapsed rapidly. Comparison shows that the vertical velocities can affect the structural response of the airplane airframe the most strongly, the following are landing elevations, and the weakest are horizontal velocities.