Numerical simulation of vibration and noise characteristics of water entry impact of amphibious aircraft

In response to the analysis requirements of the vibration and noise caused by the impact of amphibious aircraft entering the water, this paper studies the influence of forward speeds and entry angles on the water entry impact vibration and noise of amphibious aircraft.

First, based on the arbitrary Lagrangian-Eulerian (ALE) algorithm, a finite element model of an amphibious aircraft is established and its motion characteristics in the water entry impact stage under different forward speeds and water entry angles are analyzed. Next, based on the statistical energy snalysis (SEA) method, a SEA model of an amphibious aircraft is established and its water entry impact vibration and noise characteristics are studied, as well as the influence of forward flight speed and entry angle.

The results show that the lower the water forward speed, the smaller the response of the amphibious aircraft to the hydrodynamic impact, the less roll and the slower the longitudinal velocity decrease. The noise in the cockpit of the amphibious aircraft shows a trend of reducing across the entire frequency range. The effect of water entry angle on cockpit noise is not significant. Compared with other angles, the water entry angle of 4° has the greatest impact on the hydrodynamic impact of the amphibious aircraft, but the best lateral stability.

By controlling the appropriate forward speed and water entry angle, the water entry attitude and cabin noise control can be taken into account.