Analysis of hydrodynamic characteristics of unmanned underwater vehicle moving close to the sea bottom

TLDR

The hydrodynamics of unmanned underwater vehicles operating near the sea bottom is crucial for their maneuverability. This study investigates how drag, lift, and pitching moment of a UUV vary with distance to the bottom and attack angle. A structured computational grid at varying distances and attack angles was created with Ansys ICEM, and the flow field was simulated using CFX. Results show that drag coefficient rises as distance decreases and as attack angle increases, lift coefficient increases with attack angle, an attraction force appears that grows as distance decreases, and the absolute pitching moment coefficient increases with decreasing distance and increasing attack angle.

Abstract

The accurate research on the hydrodynamics of unmanned underwater vehicle (UUV), which moves close to the sea bottom, has a great significance for its maneuverability. The structured grid of the computational models with different distances to the sea bottom and attack angles is generated by Ansys ICEM, and the flow field near the sea bottom is simulated using CFX. The characteristics of the drag, lift, pitching moment influenced by the distance to sea bottom and the attack angle are studied. The result shows that the drag coefficient increases with the decrease of distance, while it increases with the increase of attack angle. There exists attraction force when UUV moves close to the sea bottom, and the attraction force increases with the decrease in distance. The lift coefficient increases with the increase in attack angle. The absolute value of the pitching moment coefficient increases with the decrease in distance and the increase in attack angle.