Numerical study of ditching characteristics of a transport aircraft by global moving mesh

This paper numerically investigates the ditching characteristics of the NACA TN 2929 model. In the simulation method, the RANS equation and realizable k-ε turbulence model are solved by the finite volume method; the volume-of-fluid method is used to capture the water-air interface; the six degree of freedom model and the global moving mesh (GMM) method are used to deal with the relative motion between the water and the object. GMM is a new dynamic mesh method which is proposed to simulate water entry problems. In GMM, the whole computational domain and boundaries move together with the object to avoid the high computational expense and low quality mesh in the traditional mesh deformation method. This numerical method is applied to simulate the water impact of a 2D cylinder in free fall, and the results show a good agreement with the experimental data. The effect of each aerodynamic part of the NACA TN 2929 model on the ditching behavior is studied in detail, and the results show that aerodynamic loads cannot be ignored when analyzing the ditching motion of the aircraft.