Abstract

In this study, the flow characteristics and heat transfer performance of rib channel installed with four types of multigap, 45°-angled rib turbulators on the top and bottom walls are numerically investigated using ANSYS Fluent version 19, and an optimal rib structure that facilitates enhanced heat transfer performance is determined. The analyzed structures are as follows: Case 1: inline-type ribs without gaps, Case 2: inline-type ribs with multiple gaps (similar gaps on the top and bottom walls), Case 3: staggered-type ribs with multiple gaps, and Case 4: inline-type ribs with multiple gaps (different gaps on the top and bottom walls). The numerical results show that the presence of multiple gaps within the rib channel (Cases 2, 3, and 4) generates additional flows, increases the vortical motion and secondary recirculation flow, and decreases the pressure loss. In addition, the staggered-type rib structure in Case 3 generates multiple vortical motions and enhances the mixing flow to improve the heat transfer performance. Therefore, a multigap, staggered-type rib structure in a parallel 45°-angled rib channel is most effective in increasing the heat transfer and decreasing the pressure loss.

摘要

在本研究中，使用 ANSYS Fluent 19 版对在顶壁和底壁上安装了四种类型的多间隙、45°角肋片湍流器的肋片通道的流动特性和传热性能进行了数值研究，并采用了一种优化肋片结构，以促进增强确定传热性能。分析结构如下： 案例1：无间隙直列式加强筋 案例2：多间隙直排式加强筋（顶壁和底壁间隙相似） 案例3：多间隙交错式加强筋案例4：多间隙的直列式加强筋（顶壁和底壁的间隙不同）。数值结果表明，肋槽内存在多个间隙（案例 2、3 和 4）会产生额外的流动，增加涡动和二次再循环流动，并减少压力损失。此外，案例3中的交错式肋结构产生了多次涡动，增强了混合流动，提高了传热性能。因此，平行 45° 角肋通道中的多间隙、交错型肋结构在增加传热和降低压力损失方面最有效。