Abstract Effects of insertion of a straight tape mounted with double-sided V-baffles used as a longitudinal vortex generator (LVG) on turbulent convection heat transfer behaviors in a constant heat-fluxed tube in the Reynolds number (Re) range of 4120 to 25,800 are experimentally and numerically investigated. In the present experiment, the V-baffles at a fixed attack angle (α = 30°) were placed on the tape with two arrangements: V-apex pointing downstream and upstream (hereinafter called “V-down” and “V-up”). The V-down and up tapes with three baffle height ratios, (RB = b/D = 0.20, 0.15, 0.10) and pitch ratios, (RP = P/D = 1.5, 1.0, 0.5) were tested. Data of the current smooth or plain tube were also examined for comparison. The experimental results have shown that the employ of the V-down tape generally yields higher heat transfer, friction loss and thermal performance than that of the V-up one. A new derived thermal-performance enhancement factor (TEF) is proposed. The maximum TEF of the V-down tape is around 2.07 at RB = 0.15, RP = 1.0 and is, in average, about 1.4% higher than the V-up one having its peak of 2.04. A 3D numerical V-baffled-tube flow model was also simulated to examine the fluid flow and heat transfer patterns. The numerical validation was seen in close agreement with available experimental data. Numerical heat transfer contours and flow structures were also reported.

中文翻译：

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配备 V 型挡板带的管式换热器中的增强传热

摘要 在雷诺数 (Re) 范围为 4120 至 25,800 的恒定热通量管中，插入安装有双面 V 形挡板用作纵向涡流发生器 (LVG) 的直带对湍流对流换热行为的影响进行了实验和数值研究。在本实验中，固定攻角（α = 30°）的 V 形挡板以两种排列方式放置在胶带上：V 形顶点指向下游和上游（以下称为“V-down”和“V-up”） ）。测试了具有三个挡板高度比（RB = b/D = 0.20、0.15、0.10）和节距比（RP = P/D = 1.5、1.0、0.5）的 V 型向下和向上胶带。还检查了当前光滑或平坦管的数据以进行比较。实验结果表明，使用 V 型向下胶带通常会产生更高的热传递，摩擦损失和热性能优于 V-up 之一。提出了一种新的衍生热性能增强因子 (TEF)。V-down 磁带的最大 TEF 在 RB = 0.15、RP = 1.0 时约为 2.07，平均比 V-up 磁带的峰值 2.04 高约 1.4%。还模拟了 3D 数值 V 形挡板管流动模型，以检查流体流动和传热模式。数值验证与可用的实验数据非常一致。还报告了数值传热轮廓和流动结构。还模拟了 3D 数值 V 形挡板管流动模型，以检查流体流动和传热模式。数值验证与可用的实验数据非常一致。还报告了数值传热轮廓和流动结构。还模拟了 3D 数值 V 形挡板管流动模型，以检查流体流动和传热模式。数值验证与可用的实验数据非常一致。还报告了数值传热轮廓和流动结构。