Study Of Drag Reduction For High-speed Underwater Vehicle

The main contents contain drag reduction analysis for supercavity vehicle and numerical study for the shape with negative pressure gradient in this paper.High-speed underwater vehicle is a body moving in cavity. The velocity analytical expression in the stage of initial navigation regime is given. The optimization mathematical model is established in the condition of the velocity as the goal function and the diameter and the angle of the cavitator as the design variable. Basing the complex optimization algorithm the common optimization procedure was programmed. Finally through an example of optimization computation, the validity of the method proposed in this paper is confirmed. The load characteristics of the vehicle are analyzed. The vehicle trajectory mathematical model owned initial perturbation of the thrust force bias as well as the assemble technology error is established. The trajectory simulation program owned initial perturbation is programmed, and a model is simulation calculated in the situation of various initial perturbations. The influence curves of initial perturbation to the vehicle trajectory characteristics are obtained.Separate characters of the axial symmetry shape with negative pressure gradient (ASSWNPG) are simulated and the results are compared with the Nesteruk's experimentation data. Cavitation characters of ASSWNPG are calculated based the traditional nucleus theory for cavitation incipient. The pressure distribution of the potential theory and wind tunnel test are confirmed and the separation phenomenon isn't observed in the range of Reynold's number computed. However, the cavitation phenomenon of ASSWNPG is observed and a supercavity is formed.