Laminar Flow and Heat Transfer Characteristics in Jackets of Triangular Flow Channels

Laminar flow and heat transfer characteristics of jacketed vessel with triangular flow channels were numerically studied under hydrodynamically and thermally fully developed conditions. Constant heat flux at theheated wall was assumed. The numerical program code interms of vorticity, stream function, axial velocity com ponent and energy equations was written based on a finite volume method. Based on the numerical results, the flow and temperature field were given, and the effects of Dean and Prandtl numbers on flow and heat transfer were ex amined, and the correlations of flow resistance and mean Nusselt number were developed for the jacket. The results show that the structure of secondary flow is steady two vortices in the investigated range of dimensionless curvatureratio and Reynolds number. Two peaks of local Nusselt number increase significantly with Prandtl and Dean num ber increasing, but the local Nusselt numbers near two ends and at the center of the heated wall increase only slightly. The center and two ends of heated wall are the poor positions for heat transfer in the jacket. Compared with the outer half coil jacket at the same area of heated wall, curvature radius, Reynolds number and Prandtl number, e jacket of triangular flow chmnel has lower flow resistance and less mean Nusselt number.

有三角形的流动隧道的 jacketed 容器的 Laminar 流动和热转移特征数字地被学习在下面充分 hydrodynamically 并且热地开发了条件。在激烈的墙的经常的热流动被假定。以涡度，流函数，轴的速度部件和精力，方程基于一个有限的卷方法被写的数字程序代码。基于数字结果，流动和温度地被给，并且流动和热转移上的迪安和 Prandtl 数字的效果被检验，并且流动抵抗的关联和吝啬的 Nusselt 数字为夹克衫被开发。结果证明第二等的流动的结构是稳定的在无尺寸的弯曲比率和雷纳兹的调查范围的二个旋涡数。本地 Nusselt 数字的二座山峰与 Prandtl 和迪安数字增加显著地增加，但是本地 Nusselt 数字接近二结束并且仅仅稍微在激烈的墙的中心增加。中心和激烈的墙的二结束是为穿夹克衫的热转移的差的位置。在激烈的墙，弯曲半径，雷纳兹数字和 Prandtl 数字的一样的区域与外部一半相比卷夹克衫，三角形的流动隧道的夹克衫有更低的流动抵抗和不太吝啬的 Nusselt 数字。