Numerical Simulation and Analysis Method of Civil Aircraft Ditching Based on MSC.Dytran

Conformity analysis of civil aircraft ditching is a requirement of CAAC airworthiness regulations. The compliance analysis of aircraft ditching includes the analysis of load, strength and floating characteristics. The validation of ditching loads requires laboratory tests to collect the data needed for structural strength calculations of the airframe. MSC.Dytran, a commercial finite element software, was used to solve the nonlinear transient fluid-structure coupling problem between the aircraft, air and water using the general coupling method. The pressure distribution of the vertical overload at the center of gravity, the bottom of the aircraft fuselage on the water, the engine nacelles and the horizontal tail during ditching is analyzed. The numerical simulation results are used to support the water landing laboratory tests. This paper is of great importance to the airworthiness study of the floating characteristics of civil aircraft landing on water.

I. Background

For civil aircraft, airworthiness regulations must be met. Aircraft are flown with water landings in mind. The FAA and European Joint Airworthiness Regulations require that all large transport aircraft must be validated for water landing performance by model tests or by analysis and extrapolation by analogy. China's civil aircraft airworthiness regulations on the civil aircraft water forced landing capability of the validation has also made clear provisions ^[1]. Civil aircraft must meet the airworthiness regulations if they want to obtain the airworthiness certificate. Therefore, the study of civil aircraft landing on water is essential to obtain the airworthiness certificate.