Mojtaba Dehghan Manshadi, Kazem Hejranfar, Amir Hamzeh Farajollahi,
Volume 12, Issue 24 (1-2017)
Abstract
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 and hydrodynamic noise. The influence of the horseshoe vorex on the submarine performance is not negligible. 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 standard underwater model employing the vortex generator by using the oil flow visualization method and CFD method (OpenFOAM code) in 0°≤α≤30° angles of attack. In this study, the application of experimental method in wind tunnel and CFD simulation which can help us to precisely study the structure of vortical flow field. The results show that Vortex Generators placed along the submarine do indeed significantly reduce strength of the horseshoe vortex, line separation, size of cross-flow vortices and drag force.
Amirhamzeh Farajollahi, Mojtaba Dehghan Manshadi, Kazem Hejranfar,
Volume 14, Issue 28 (1-2019)
Abstract
The vortex generated around a submarine has an important influence on the uniformity of the submarine wake at the propeller and hydrodynamic noise. A suitable way to reduce the effects of this separated flow is to use vortex generators. Vortex generators have different arrangement such as counter-rotating and co-rotating. The main goal of the present study is to investigate the flow field around a standard underwater model employing the vortex generator with different arrangement by using the CFD method (OpenFOAM code) in 0°≤α≤30° angles of attack. In this study, the application of CFD simulation which can help us to precisely study the structure of vortical flow field. The results show that counter-rotating vortex generators placed along the submarine do indeed significantly reduce strength of the vortex, line separation, size of cross-flow vortices and drag force. The amount of the drag reduction for the counter-rotating vortex generator is approximately 14% in α=30° and approximately 21% in β=30°.
