Turbulent flow acceleration and abnormal intensification of the separated flow in a channel with dense arrangement of inclined single-row oval-trench dimples
S.A. Isaev1,2,3, M.S. Gritskevich1, A.I. Leontyev4, O.O. Milman3, D.V. Nikushchenko1
1Saint-Petersburg State Marine Technical University, Saint-Petersburg, Russia
2Saint-Petersburg State University of Civil Aviation, Saint-Petersburg, Russia
3Kaluga State University named after K.E. Tsiolkovski, Kaluga, Russia
4Bauman Moscow State Technical University, Moscow, Russia
Keywords: наклоненные овально-траншейные лунки, узкий канал, интенсификация течения, inclined oval-trench dimples, narrow channel, flow intensification
Abstract
On the basis of the Reynolds-averaged Navier-Stokes equations closed by the shear stress transport model with the consideration of streamline curvature, turbulent flow acceleration in the channel with inclined single-row oval-trench dimples, earlier found in the laminar regime, has been revealed. It is shown that the velocity in the flow core increases up to 1.4 times when dimples are densely packed. The influence of the dense arrangement of dimples on abnormal intensification of the separated flow in the stabilized area of the channel has been assessed. Absolute friction in the backflow zone in the dimple is found to grow up to 5.5 times compared with friction at the smooth channel wall.
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