Experimental Investigation of Horseshoe Vortex Structure at Body-Sail Junction over Submarine Model by Using Oil Flow Visualization and Hot Wire Probe

The flow field around the axisymmetric streamlined bodies which forms the main body of the airplanes and submarines has been the subject of several researches. The Underwater vehicles yawed to freestream flow, like submarines in a turning maneuver, produce large vortical separated regions. This vortical flow affects acoustic and non-acoustic stealth, body drag, control effectiveness and maneuverability. The horseshoe vortex generated around the sail-body junction of a submarine has an important influence on the uniformity of the submarine wake at the propeller. The influence of the horseshoe vorex on the submarine performance is not negligible. The horseshoe vortex will increase the submarine hydrodynamic noise, and increase the non-uniformity of the flow at the propeller. The main goal of the present study is to investigate the flow field around a standard underwater model with sail by using the oil flow visualization method and hot wire probe in 0°≤ α ≤30° angles of attack. The novelty of the this study is the application of oil flow visualizing method and hot wire probe which can help us to precisely study the structure of three-dimensional vortical flow field. Here, the size of vortices and the location of separation region along the model at different angles of attack are obtained by using the oil flow visualization and hot wire measurement results and some conclusions are made.

کلیدواژه ها:

Horseshoe Vortex ، Oil Flow Visualization ، Hot Wire Probe