Hydrodynamic study of hybrid aerial underwater vehicle in the wind, wave, and current environment

Hybrid aerial underwater vehicles (HAUVs) are capable of underwater movement, air mobility, and repeated trans-media movement. For HAUV, the trans-media ability under the wind, wave, and current is a unique technical difficulty. This paper calculates the wind, wave, and current loads of HAUV under different draft depths based on the computational fluid dynamics (CFD) method. In the uniform current condition, when the arm is completely submerged under water, the horizontal hydrodynamic force on the HAUV body increases by about 50% compared to when the arm is completely out of water. With the decrease of draft depth, the hydrodynamic torque of HAUV under the uniform current action shows a downward trend, then a reverse increase, and a reverse decrease to 0. The calculation results show that the wind has little influence on the HAUV body near the water surface. The wave force and torque of HAUV are different under different draft depths, particularly the time corresponding to the peak. At different waves, the hydrodynamic force and torque of HAUV are greatly different in the trend and peak. The research results help understand the dynamic characteristics of HAUV under the action of wind, wave, and current and are useful for the motion control simulation of HAUV subject to variable disturbances.