The effects of the geometrical arrangement of fins on the streamlines, pressure drop and heat transfer in louvered fin and tube compact heat exchangers were numerically studied using the ε-NTU method. The effects of pitch variation, angle, the number of louvers, and flow redirection location in a series of the fins, as well as non-louvered inlet and exit fin length were investigated. Also, the effects of the aligned, non-aligned, positive, and negative louver angles were examined. The simulation results show that the redirection of streamlines depends on the louver angle and the distance of flow re-direction location from the inlet edge of the fin and not on the non-louvered inlet and exit fin lengths, fin pitch, or the number of louvers. Moreover, based on the obtained results, the angle relative to horizon of suction or blowing direction does not affect heat exchanger efficiency. In contrast, the alignment of suction or blowing directions in multiple fins has a significant impact on heat exchanger performance, increasing the amount of heat transfer by 40 %. An analytical equation has been proposed for estimating the maximum height of flow deviation based on two effective parameters of louver angle and the distance of flow redirection location from the inlet edge of the fin.

使用ε-NTU方法，数值研究了翅片的几何布置对流线型，百叶窗式翅片管紧凑型换热器中的流线，压降和传热的影响。研究了螺距变化，角度，百叶窗数量和一系列翅片中的流重定向位置以及无百叶窗的入口和出口翅片长度的影响。同样，检查了对准，不对准，正和负百叶窗角度的影响。仿真结果表明，流线的重定向取决于百叶窗角度和流向重定向位置的距离，即距离鳍片入口边缘的距离，而不取决于非百叶窗式入口和出口鳍片的长度，鳍片节距或数量百叶窗。而且，根据获得的结果，相对于吸气方向或吹气方向的角度不会影响热交换器的效率。相反，多个翅片中吸气或吹气方向的对准对热交换器的性能有重大影响，使传热量增加40％。已经提出了一个解析方程，用于基于百叶窗角度的两个有效参数以及与鳍片进口边缘的流向重定向位置之间的距离来估计流向偏离的最大高度。