Effects of rotation on the trailing vortex and heat transfer from a horizontal rotating cylinder at higher Grashof number

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• 作者：Hongting Ma ; Wenqian Lu ; Weiye Zhou ; ^{zhouweiye@tju.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Zequn Ding ; Xinyu Lü ; Yang Cao ; Yufeng Zhang ; Na Deng
• 关键词：Horizontal rotating cylinder ; Heat transfer ; Trailing vortex ; Deflection angle
• 刊名：International Communications in Heat and Mass Transfer
• 出版年：2015
• 出版时间：November 2015
• 年：2015
• 卷：68
• 期：Complete
• 页码：20-26
• 全文大小：697 K

文摘

In the present study, effects of rotation on the trailing vortex and heat transfer from a large diameter horizontal rotating cylinder in still air have been experimentally investigated whereas earlier studies considered cylinders with smaller diameters. As the rotational speed n is increased, the trailing vortex would deflect in the rotational direction, the flow state of air near the cylinder would vary from laminar to turbulent, the heat transfer would transit from pure natural convection to mixed convection, and finally to pure forced convection resulted from rotation, the trailing vortex would break down and disappear. The variation of deflection angles ω   with the parameter $R{e}_r/\sqrt{Gr}$ can be expressed as $w=32.3R{e}_r/\sqrt{Gr}$ at lower rotational speed. The discriminant to determine the disappearance of trailing vortex can be presented as Re_r²/Gr = 7.51.