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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 present study aimed to investigate the flow field around a standard submersible model in various angles of attack by employing two visualization methods. The vortex structures around the model are qualitatively studied at the 40-degree angle of attack in a vertical wind tunnel. These structures are visualized by the laser sheet illumination of the smoke injected flow. The shear stress field lines on the model surface in the 0≤ α ≤35° angles of attack became visible by oil and pigments. Noteworthy and distinct aspect of the present study is the application of two empirical visualizing methods which made three dimensional vortical field more understandable. Formation and development of the primary and secondary vortex along the model length are qualitatively interpreted by the results of the smoke and laser light visualization technique. Moreover, the primary and secondary separation lines along model length for various angles of attack were deduced from the results of the oil flow visualization.

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The fThe flow field around the axisymmtric stream lined bodis which forms the main body of the airplaines and submarines has been the subject of several researches. Turning maneuvers of submarines result in cross flow separation that generates large hydrodynamic forces. The separation of a simple axisymmetric body is very complex in nature. Understanding these vortical flows is paramount to improving vehicle performance and design. A suitable way to reduce the effects of this separated flow is to use vortex generators. The main goal of the present study is to investigate the flow field around a Suboff standard underwater model employing the vortex generator by using the oil flow visualization method and CFD method (OpenFOAM code) at 0° ≤ α ≤ 30° angles of attack. The novelty of the this study is the application of oil flow visualizing method and CFD simulation which can help us to precisely study the structure of three-dimensional vortical flow field. The results show that Vortex Generators placed along the submarine do indeed significantly reduce cross flow separation, size of vortices and drag forces.