Expeerimental Investigation of the Sail Position of a Submarine on the Downstream Flow Field

A submarine is an underwater vehicle that includes a main body and various appendages. The flow field around the bare body at zero angle experiences almost no separation and vortex generation. Nevertheless, when the appendages are mounted on the body, the streamlines are influenced by the body shape and a complex vortical flow field is created. Vortical flows around the hull have a significant effect on its performance. One of these vortices is the horseshoe vortex that forms at the junction of the sail and the hull body. A submarine sail has an airfoil shape that is a place to enter and exit for the crew and also is a room for installing the control and communication devices. The sail has a significant influence on the hydrodynamic equilibrium and stability of the submarine. Figure 1 shows a schematic of the horseshoe vortex formed around the sail on the hull.