The article presents an experimental study on heat transfer and friction behaviors in a solar air duct fitted with multiple V-shaped ribs on the absorber and delta-grooves on the back plate. Measurements were carried out in the test duct having a cross-section of width, W = 300 mm and height, H = 27 mm. The air flow rate inside the duct was varied to have Reynolds numbers based on the duct hydraulic diameter from about 7000 to 30,000. Two vortex flow devices: rib and groove turbulators, were introduced to generate the vortex flows along the duct. In the test duct, the upper/absorber plate having a constant heat-flux was mounted repeatedly by multiple V-shaped thin ribs with an attack angle (α) of 45° relative to main flow direction while the lower/back plate was grooved periodically in the delta/triangular shape with an attack angle (θ) of 60°. In the present investigation, the geometrical parameters of the ribs included three different rib- to duct-height ratios (e/H = B_R = 0.108, 0.162 and 0.217) and three rib-pitch to duct-height ratio (P/H = P_R = 1.0, 1.5 and 2.0). The experimental results have shown that the duct with the V-ribbed absorber at B_R = 0.217, P_R = 1 in conjunction with the delta-grooved back plate has the greatest heat transfer and pressure loss. However, the use of the combined devices with P_R = 1, B_R = 0.108 leads to the highest thermal performance and also provides greater heat transfer and thermal performance than employing the V-rib or the delta-groove alone.

这篇文章介绍了在太阳能风管中的传热和摩擦行为的实验研究，该风管在吸收器上装有多个V形肋，在背板上装有三角槽。在具有宽W ＝ 300mm 和高H ＝ 27mm的横截面的测试导管中进行测量 。根据导管的液压直径，将导管内的空气流速改变为具有雷诺数，其范围为约7000至30,000。引入了两个涡流装置：肋和槽湍流器，以沿管道产生涡流。在测试管道中，具有恒定热通量的上/吸收板通过具有攻角（α）相对于主流方向成45°），而下/背板以三角形/三角形形状以60°的迎角（θ）周期性开槽。在本研究中，肋的几何参数包括三种不同的肋与风管高度之比（e / H  =  B _R  =  0.108、0.162和0.217）和三种肋距与风管高度之比（P / H  =  P _R  =  1.0、1.5和2.0）。实验结果表明，带有V型肋式吸收器的管道在B _R  =  0.217，P _R  = 1与三角形凹槽背板配合使用具有最大的热传递和压力损失。但是，与单独使用V型肋或三角形凹槽相比，使用P _R  =  1，B _R  =  0.108的组合设备可获得最高的热性能，并且还提供更高的热传递和热性能。