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ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Wake stability enhancement by mean of non-isothermal blowing

Get access (open in a dialog) DOI: 10.1615/IHTC12.90
6 pages

Abstract

The in uence of blowing through the porous surface of a circular cylinder onto the external flow is investigated through numerical simulations. The main ow is laminar (Re ∈ [40; 65]). It is shown that blowing through the rear part of the cylinder tends to stabilize the flow, hence leads to higher critical Reynolds numbers (the transition to unsteady flow is postponed). Theoretical arguments are proposed to bring a physical explanation of this phenomenon. When the fluid blown is at a lower temperature than the main flow, hence denser, two opposite phenomena occur. The blowing stabilizes the wake while the density di erence enhances its instability. Study of the instability temporal growth rates evolution in the wake for di erent blowing distributions are also presented and allows for further conclusions.