Numerical Simulation Analysis of Unseparation Aix-symmetry and 2D Shape

The shape with negative pressure gradient (NPG) is the necessary condition that can ensure vehicle moving in water not to separate. Separation and cavitation characters of shape U-1 with NPG were simulated, and the results were compared with the Nesteruk's experimentation data. According to the potential theory, two different aerofoils with NPG were designed. Considering different angle of attack and different Reynolds number, separation characters were numerical calculated for two different shapes with NPG. The pressure distribution of the potential theory and wind tunnel test results are confirmed, however, the cavitation phenomenon is observed and a super cavity is formed for U-1. Boundary layer separation phenomenon is observed for the aerofoil with bigger positive pressure gradient (PPG) in all numerical condition and the one with less PPG with better separate characters.