Analysis of Water Landing Overload of the Double-stepped Wing-in-ground Aircraft

Abstract

During the landing process of wing-in-ground aircraft,the impact caused by the landing of broken steps is likely to lead to the buckling or damage of the structural surface.The Arbitrary Lagrangian-Eulerian(ALE)finite element method is utilized to simulate the water landing of a wing-in-ground aircraft,and the penalty function method is used in the two-phase interface fluid-solid interaction problem.The effect of different parameters such as horizontal flight velocity,falling velocity,pitch angle on the immersion depth,and overload are analyzed.The results show that the pressure maxima of the aircraft with water landing all occur at the broken step.With the increase of the pitch angle,the peak of vertical overload rises and then falls,while the peak of horizontal overload keeps reducing.When the pitch angle is 7°,the vertical overload peak reaches the highest,which is 1.4 times that of the lowest overload in the pitch angle of 15°.On the other hand,the peak of the horizontal overload rises as the horizontal component of flight velocity increases,and it is visible that there is no discernible effect on the peak of vertical overload.Meanwhile,an approximately linear relationship appears between the peak of vertical overload and the square of falling velocity.The larger the falling velocity,the bigger the peak of vertical overload.

Keywords

• wing-in-ground aircraft
• broken step
• water landing slamming
• overload
• pitch angle