Experimental and Numerical Investigation of Water Impact on Hull of Seaplane UAV

In this paper, theoretical and experimental simulations of the UAV hull’s structural strength in the landing phase on the water surface have been studied. In the seaplane design, calculating the strength of the hull structure against impact from the water surface is of special importance. Initially, the hull was numerically simulated using the finite element method, the interaction of the structure with the fluid (two-phase). Then, by performing an experimental study with variable speed, the results of numerical solution and experimental experiment are compared and evaluated. Comparing the results and graphs obtained from the numerical method with experimental experiments, it has been observed that throwing the seaplane free fall on the water surface can be a simulation of the most critical state for landing. The results show that increasing the descent height and velocity of the device when colliding with the water surface, causes the highest strain gradient along the axis perpendicular to the floor of the waterfowl and the least changes along the axis tangential to the water surface. According to the data obtained from the Tsai Hill and Tsai Wu rupture criteria for numerical solution and experimental testing, the values of stress and strength of the seaplane hull structure are within the allowable design range.