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Showing 2 results for Vortex Generator
Mojtaba Dehghan Manshadi, Kazem Hejranfar, Amir Hamzh Farajollahi,
Volume 15, Issue 6 (8-2015)
Abstract
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.
M. Garshasbi, M.m. Jafari, H. Parhizkar,
Volume 19, Issue 2 (2-2019)
Abstract
Today, the effects of three-dimensional flow near the blade and wing tip in the turbomachinery industry, such as rotor helicopters, turbine, as well as wings optimization in the airline industry, for safe flight with high maneuverability, are the focus of the industry in this area. Stall can be considered an influential phenomenon in this field. In the present study, the flow separation control was investigated by a vortex generator on a wing of a radar invader UAV, including a Naca64a210 airfoil with a 5° washout angle at the wing tip and integrated wings and attached to the body with a 47° sweep angle in the subsonic flow. The turbulent flow was solved by the kw-sst method for attack angles ranging from 5-20° and speeds of 30 and 60 m/sec. The results show a good fit with numerical and experimental results so that the pressure distribution curves indicate the growth of pressure in the vortex generating regions and also the areas near the tip of the wing, which results in the flow remain in the wing surface in these areas. Therefore, by examining the pitching moment and velocity contours, it can be seen that the flow separation from the 15° angle of attack, has been delayed to 20°, and also the ability to control the separation of flow along with the growth of velocities has been achieved.
