Numerical research on slamming characteristics of aircraft landing on water

In order to investigate the impact characteristic of an aircraft landing on water, a computational fluid dynamics (CFD) simulation is conducted to explore the slamming characteristics of the NACA TN 2929 A model. The flow around the model is solved by using Reynolds-averaged Navier-Stokes equations with the shear stress transport (SST) k - omega turbulence model, based on finite volume method (FVM). The free surface is captured by using the volume of fluid (VOF) method, and the aircraft impact process is realized with help of overset mesh technology. Then, the effects of horizontal and vertical velocities and initial pitch angle on the slamming load, attitude change, impact pressure and flow field evolution are investigated. The results reveal that the horizontal velocity has a considerable influence on whether the aircraft's horizontal tail hits the water, and further affects the maximum vertical load as well as the maximum pitch angle throughout the impact process. The vertical velocity determines the slamming load before the horizontal tail strikes the water, while the horizontal velocity has a significant effect on the load after the horizontal tail hits the water. A smaller initial pitch angle results in not only a heavier slamming load but also a more dramatic change of the posture after the aircraft impacts the water. The impact pressure of the aircraft is maximized at the junction of the approaching surface of the fuselage and the free surface. In some cases, the pressure is also concentrated on the undersurface of the horizontal tail.