Investigation of Wave Characteristics and Wave Resistance of an Underwater vehicle with Control Surface Near the Free Surface

Underwater vehicles in industrial applications, have various control surfaces for stability, maneuverability, gudance and control. These control surfaces affect the body hydrodynamic characteristics, including the resistance forces and the form of the generated wave due to the motion of the vehicle near the free surface. In this paper the effect of a vertical control surface on the hydrodynamic characteristics of an underwater vehicle near free surface is studied using Boundary Element Method.Results, including characteristics of free surface wave, pressure coefficient and wave resistance are calculated for Froude numbers in the range of 0.1-0.5 and non dimensional submergence depths of 1.25, 2.25, 3.5 & 4.5 for the bare model and model with control surface. Comparing BEM and experimental results shows the discrepancy of less than 3% for maximum free surface wave height and 17% for wave resistance. Predicted results indicates that control surface causes an increase of about 13% in maximum free surface wave height and 16% in wave resistance. This increment is due to the interaction of the main body with control surface and also direct relation of wave resistance with free surface wave height.