Numerical study on maximum impact load during aircraft ditching on wave surface

This paper uses numerical methods to study the magnitude of the maximum impact load on the fuselage and its physical cause during the compulsory landing of the wave. In the numerical calculation, the finite volume method and Volume of Fluid (VOF) method are used to capture the free surface. The Six-Degree-of-Freedom (6DOF) model and the Global Motion Mesh (GMM) are used to process the relative motion between water and the aircraft, and simulate the forced landing process of the aircraft. By selecting the wavefront phase of the aircraft that has the maximum sinking speed relative to the water surface as the position of the forced landing water contact, the ultimate impact load on the fuselage is predicted. The results show that during the water-impacting stage of the wavy surface, the fuselage encounters an unforeseen impact peak on a calm water surface, and the magnitude of the impact peak is related to the sinking speed of the aircraft relative to the water surface. This paper also compares the movement attitude and overload change history of aircraft forced landing under five different wave height sea conditions, and gives the influence rules of wave height on the maximum impact load and the peak values of other parameters, which provides a reference for the design of aircraft load distribution. © 2021, Editorial Board of JBUAA. All right reserved.