To reduce the pressure drop penalties with substantial heat transfer enhancements for the channel flows enhanced by a twisted tape insert, the conjugate inclined ribs and slots are newly devised to modify the twisted tape. The simulated flow and pressure fields generated by the inclined rib-slot element along a twisted tape are correlatively examined with the measured Nusselt numbers and Fanning friction factors. The tilted transverse ribs convert the flow re-circulation cell behind a vertical rib to the solenoidal vortex and trip the separated flows. The inclined slots enable the mass, momentum and energy exchanges between the two axial swirls along the two spiral pathways segregated by the twisted tape. These flow mechanisms induced by the twisted tape and the inclined ribs and slots act synergistically to improve the heat transfer performance with the lessened rib-induced form drags. The average Nusselt numbers are raised to 4.2–3.8 time of the Dittus-Boelter values at the expenses of the Fanning friction factor augmentations to 32.5–40.2 time of the Blasius levels at the range of Reynolds number between 10,000 and 50,000. Compared with the tubular flows enhanced by the ribbed twist tape, the heat transfer enhancements caused by the rib-slot element along a twisted tape in a square duct are similarly retained but the reductions in Fanning friction factor are substantial. The resultant aerothermal performance improvements achieved by the inclined rib-slot element lighten the prospective applications to heat exchangers involving swirl generators. To assist these applications, the empirical correlations that calculate the average Nusselt number, Fanning friction factor and relative heat transfer power of a square duct enhanced by the twisted tape with the inclined slots and ribs are devised.

为了通过扭曲带插入物增强的通道流的显着传热增强来减少压降损失，新设计了共轭倾斜肋和槽来改进扭曲带。由倾斜的肋槽元件沿扭带产生的模拟流场和压力场与测量的努塞尔特数和范宁摩擦系数进行了相关检查。倾斜的横向肋条将垂直肋条后面的流动再循环单元转换为螺线管涡流并阻止分离的流动。倾斜槽使两个轴向漩涡之间的质量、动量和能量交换能够沿着由扭曲带分隔开的两条螺旋路径进行。这些由扭曲带和倾斜肋条和槽引起的流动机制协同作用以提高传热性能，同时减少肋条引起的形式阻力。在雷诺数介于 10,000 和 50,000 之间的范围内，平均 Nusselt 数提高到 Dittus-Boelter 值的 4.2-3.8 倍，代价是 Fanning 摩擦系数增加到 Blasius 水平的 32.5-40.2 倍。与由带肋扭曲带增强的管状流动相比，由肋槽元件沿方形管道中的扭曲带引起的传热增强同样保留，但范宁摩擦系数的降低是显着的。通过倾斜的肋槽元件实现的空气热性能改进减轻了涉及涡流发生器的热交换器的预期应用。