Research on drop shock dynamic performance of air-cushion aircraft on ground and water surface

Aircraft with traditional landing gear have difficulty adapting to complex take-off and landing environments such as water, sand and uneven surfaces. In this study, simulations and experiments of the ground and water landing performances of an amphibious air-cushion aircraft were conducted to demonstrate its amphibious landing capabilities. Based on membrane and gas thermodynamics theories, the dynamic response problem of a transport aircraft with an air cushion landing system (ACLS) was investigated. First, the shape prediction curve of the airbag was designed and implemented in MATLAB/Simulink based on membrane theory and the finite element method, and then the mass–volume–pressure of the airbag in the ACLS was calculated according to the ideal gas equation of state. Second, considering the fluid-structure interaction effects of the air cushion water entry, dynamic models of the air-cushion aircraft on the ground and under calm water surface were established in MATLAB/Simulink to study the dynamic performance of the air-cushioned aircraft. Finally, test and simulation analyses were conducted to study the dynamic responses of the air-cushion aircraft. The maximum cavity pressure and vertical acceleration grew larger as the drop height increased, and they both converged to stability quickly. The fuselage and air cushion had good dynamic responses in the process of both ground and water landing, and the amphibious landing capability of the air-cushion aircraft was verified. This study can provide guidance for the structural and control system design of an air-cushion aircraft and lay a foundation for the water drop dynamic analysis of air-cushion aircraft.