Numerical analysis of civil aircraft ditching performance in wave condition

To study the ditching performance of civil aircraft in wave conditions, the finite volume method of computational fluid dynamics is used to solve the unsteady incompressible RANS equation. Based on the relevant requirements and suggestions of airworthiness regulations, VOF method, whole dynamic grid method, stokes fifth-order wave model and adaptive grid technology are used to construct the numerical simulation model. The research object is airbus A320-200. Firstly, the ditching process of aircraft in the calm water and wave condition is compared and analyzed. The results show that the maximum horizontal overload is 2.42 g in the wave condition, which is 1.09 times of that in the calm condition. The maximum vertical overload is 4.82 g, which is 2.82 times of that in the calm water condition. In both cases, cushion effect and diving phenomenon are obvious. In the initial stage of impact, the aircraft is affected by water suction. In the wave condition, jumping phenomenon appears, but does not have apparent effect on the ditching process. Secondly, the influence of wave factors on water ditching performance is studied. The results show that with the increase of the wave height, the maximum horizontal and vertical overload increase. With the increase of the wave length, the maximum vertical overload decreases. With the increase of the wave height and length, the maximum sinking velocity increases.