Abstract:

Enhanced heat transfer technique using vortex-induced vibration is an effective way to realize the cooling of heat exchange equipment. In this paper, based on the arbitrary Lagrange-Euler (ALE) algorithm, the two-way fluid-structure-interaction and heat transfer problem in the channel of rib-soft tail structure with different Reynolds numbers, different cross-sectional shapes, and different length-to-diameter ratios is investigated by using numerical simulations with dynamic mesh and overset mesh technique, and the main research objects are the flow and heat transfer characteristics around the rib-soft tail structure, the heat transfer characteristics of the ribbed heated wall, and the integrated flow and heat transfer capacity of the whole channel. The simulation working conditions are: Reynolds number Re = 200, 275, 351; rib cross-sectional shapes: circular and square; length-to-diameter ratio k = 2, 3, 4. The results show that, at Reynolds number Re = 275, the flow-heat transfer capability of the rib-soft tail structure with circular cross-section is better than that of the structure with square cross-section, and the rib-soft tail structure with circular cross-section is optimal when the length-to-diameter ratio k = 3; and the local heat transfer capacity around the rib is better for square cross-section structure than for circular ones. With the increase of Reynolds number at the length-to-diameter ratio k = 3, the combined flow-heat transfer capacity of rib-soft tail structure with different cross-sections increases gradually. Moreover, the integrated flow heat transfer capacity of circular cross-section with high Reynolds number and high length-to-diameter ratio is the best. Comparing the flow-heat transfer capacity with a rib structure without soft tail, for the circular cross-section rib structure, the integrated heat transfer capacity increases by 19.46% after adding the soft tail structure, whereas for the square cross-section rib, the capacity decreases slightly after adding the soft-tail. This provides a theoretical basis for studying the cooling design of heat exchange equipment.

Key words: arbitrary Lagrange-Euler Algorithm, dynamic mesh, numerical simulation, elasticity, laminar flow, heat-fluid-solid coupling, enhanced heat transfer

摘要：

基于任意拉格朗日-欧拉（ALE）方法，利用动网格技术和重叠网格技术数值模拟研究了不同Reynolds数、截面形状以及长径比下的肋柱-软尾结构在通道中的双向流固耦合换热问题。模拟工况为：Reynolds数Re = 200，275，351；肋柱截面形状：圆形和方形；长径比k = 2，3，4。研究表明：Re = 275时圆形截面肋柱-软尾结构的流动换热综合能力优于方形截面结构，k = 3时圆形截面肋柱-软尾结构的流动换热综合能力最佳，肋柱周围的局部换热能力方形截面结构好于圆形截面结构；k = 3时，随着Reynolds数的增大，不同截面形状的肋柱-软尾结构的流动换热综合能力逐渐升高，并且高Reynolds数、高长径比的圆形截面综合流动换热能力最佳；与不加软尾肋柱结构的流动换热能力进行对比发现，对于圆形截面形状的肋柱结构，增加软尾后综合换热能力增大了19.46%。

关键词: 任意拉格朗日-欧拉方法, 动网格, 数值模拟, 弹性, 层流, 热流固耦合, 强化换热