Numerical Study on the Fluid Dynamic Delay Characteristics of the Underwater Vehicle during the Manipulation Process of the Cavitator

The manipulation and control of cavitator are key to achieving the maneuvering motion of supercavitating vehicle. Based on CFD numerical simulation method, combined with dynamic mesh technology and overlapping mesh model, the motion characteristics and cavity morphology development of supercavitating vehicle under the control of the cavitation device were studied. Next, the influence of changes in the rudder angle of the cavitation device on the hydrodynamic delay characteristics was analyzed. The research results indicate that the designed control law for a cavitation device has achieved the'snake like'maneuvering process of a supercavitating vehicle. The maximum bag depth of the vehicle during this process was 0.75 meters, and the maximum horizontal displacement reached 25 meters. The tail flapping mode of the vehicle changes with the change of rudder angle. During the'lowering'motion stage, it is mainly a double-sided tail flapping motion, and during the'raising'motion stage, it is mainly a single-sided tail flapping motion. The lift of the vehicle has significant delay characteristics, and the delay time of fluid dynamics varies with changes in rudder angle and rotational speed, and is asymmetrically distributed during the tail beat period.