This work numerically and experimentally studies the heat transfer performances and flow characteristics of vortex generators (VGs) in a high aspect ratio rectangular ribbed channel with the Reynolds number ranging from 20000 to 100000. The steady liquid crystal thermography (LCT) method is adopted to link the images captured by experiments and the Nusselt numbers. Four different cases combining ribs and VGs are considered, and they are compared with a case with five continuous ribs in the channel. For the first time, the effect of winglet VGs and the tetrahedral VGs on heat transfer performance are compared. Simultaneously, two different arrangements of VGs, i.e. common-flow-down VGs and common-flow-up VGs are also studied to figure out which arrangement is better for improving the heat transfer performance. Simulations are conducted to systematically compare the fluid flow and local heat transfer characteristics to reveal the underlying thermo-fluid mechanisms of the considered cases by using three-dimensional CFD numerical simulations with a verified turbulence model, i.e., the SST k-ω model in the transition state. Results indicate that in the range of 0 < x/P < 1, the Nusselt number is enhanced to a large extent due to larger space for the flow reattachment. In addition, it is found that the winglet VGs perform better than the tetrahedral VGs. The winglet VGs with the common-flow-down arrangement give the best overall thermal performance at all Reynolds numbers in most cases. More specifically, the heat transfer performance can be improved up to 5.51% by adopting the common-flow-down VGs compared with the case having five continuous ribs. Furthermore, the flow characteristics reveal that longitudinal VGs can generate vortices to disturb the boundary layers, which can enhance the flow mixing and augment the heat transfer performance.

这项工作通过数值和实验研究了雷诺数为20000至100000的高长宽比矩形肋状通道中涡流发生器（VG）的传热性能和流动特性。采用稳态液晶热成像（LCT）方法进行链接实验捕获的图像和Nusselt编号。考虑组合肋和VG的四种不同情况，并将它们与通道中具有五个连续肋的情况进行比较。首次比较了小翼VG和四面体VG对传热性能的影响。同时，还研究了VG的两种不同布置，即共流VG和共流VG，以找出哪种布置更好地改善了传热性能。通过使用三维CFD数值模拟和经过验证的湍流模型（即SSTk-ω模型）中的三维CFD数值模拟，进行模拟以系统地比较流体流动和局部传热特性，以揭示所考虑情况的潜在热流体机理。过渡状态。结果表明，在0 <x / P <1的范围内，由于更大的流动重新附着空间，Nusselt数在很大程度上得到了增强。另外，发现小翼VG的性能优于四面体VG。在大多数情况下，采用共流式布置的小翼VG在所有雷诺数下均具有最佳的整体热性能。更具体地，与具有五个连续肋的情况相比，通过采用通用流下的VG，可以将传热性能提高至5.51％。