Low Reynolds number forced convection in three-dimensional wavy-plate-fin compact channels: fin density effects
Low Reynolds number forced convection in three-dimensional wavy-plate-fin compact channels: fin density effects
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DOI：
10.1016/j.ijheatmasstransfer.2004.10.022
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发表时间：
2005-04
影响因子：
5.2
通讯作者：
R. M. Manglik;Jiehai Zhang;Arun Muley
中科院分区：
文献类型：
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作者：
R. M. Manglik;Jiehai Zhang;Arun Muley
研究了周期发展的低雷诺数(10⩽Re⩽10 0 0)空气(Pr=0.7)空气在三维波纹板翅芯中的定常强迫对流。利用有限体积技术得到了非正交非交错网格的常性质计算解。结果表明，波纹密度对速度场、温度场、等温扇摩擦系数f和科尔本因子j的影响较大。波纹度的存在会导致流动截面壁槽区对称对反旋转螺旋涡的稳定和空间周期性增长和破坏。因此，翅片表面上的热边界层被周期性地中断，导致回流区附近的高局部热传递。然而，增加翅片密度往往会抑制再循环并限制它。当形成多对螺旋涡时，旋涡的程度随着流量的增加而增大。与相同截面的直流道相比，这显著提高了总的换热系数和阻力损失。用(J/F)性能或面积优度系数衡量的相对表面积紧实度仍随着翅片密度的增加而增加。
Steady forced convection in periodically developed low Reynolds number (10⩽Re⩽1000) air (Pr=0.7) flows in three-dimensional wavy-plate-fin cores is considered. Constant property computational solutions are obtained using finite-volume techniques for a non-orthogonal non-staggered grid. Results highlight the effects of wavy-fin density on the velocity and temperature fields, isothermal Fanning friction factor f, and Colburn factor j. The fin waviness is seen to induce the steady and spatially periodic growth and disruption of symmetric pairs of counter-rotating helical vortices in the wall-trough regions of the flow cross-section. The thermal boundary layers on the fin surface are thereby periodically interrupted, resulting in high local heat transfer near the recirculation zones. Increasing fin density, however, tends to dampen the recirculation and confine it. The extent of swirl increases with flow rate, when multiple pairs of helical vortices are formed. This significantly enhances the overall heat transfer coefficient as well as the pressure drop penalty, when compared to that in a straight channel of the same cross-section. The relative surface area compactness as measured by the (j/f) performance or the area goodness factor nevertheless increases with fin density.