百叶窗与曲面涡产生器组合式翅片管束通道内流动与传热特性

Flow and Heat Transfer Characteristics of the Channel Formed by Circu-lar Tube Bank Fins with Louvers and Curved Vortex Generators

中文关键词: 百叶窗翅片  曲面涡产生器  强化传热  数值模拟

英文关键词: Louver fin  Curved vortex generator  Heat transfer enhancement  Numerical simulation

中文摘要:

      为提升翅片管束通道内的换热性能并显著改善圆管尾部回流区域的流动特性和传热能力，提出了一种百叶窗曲面涡产生器组合式强化翅片。采用数值方法研究了该组合式强化翅片的流动和传热性能，并与平直翅片、百叶窗翅片以及曲面涡发生器翅片进行了对比分析，并探讨了通道内二次流强度和传热的关系。结果表明：组合翅片能够改善通道内的流动阻力特性，圆管后部的曲面涡发生器能够显著减小回流区面积并产生纵向涡，百叶窗和涡发生器的协同作用使通道内的大部分区域二次流强度显著高于平直翅片；同时，明显改善了翅片通道截面内的温度均匀性，强化了翅片表面的局部对流换热强度。在所研究的参数范围内，相较于平直翅片、百叶窗翅片和曲面涡产生器翅片，组合式强化翅片的Num分别提高了61.51%-91.73%、3.45%-13.33%和31.36%-48.53%，f分别提高了96.16%-117.22%、2.20%-5.41%和42.35%-56.81%，JF值变化范围为1.34-1.50。

英文摘要:

      To enhance the heat transfer performance of the channel formed by circular tube bank fins and significantly improve the flow characteristics and heat transfer capacity in the recirculation region at the rear of circular tubes, a louvers and curved vortex generators combined fin pattern was proposed. A numerical method was used to investigate the flow and heat transfer performance of this combination fin, and comparative analyses were conducted with the plain fin and the fin with curved vortex generators. Additionally, the relationship between secondary flow intensity and heat transfer within the three channels was explored. The results showed that the combination fin effectively improves the flow resistance characteristics within the channel. The curved vortex generator positioned behind the circular tube significantly reduces the size of the recirculation zone and generates longitudinal vortices. The synergistic effect of the louvers and curved vortex generators leads to a significant increase in the secondary flow intensity over most re-gions of the channel compared to the plain fin. At the same time, it noticeably improves the uniformity of the temper-ature distribution on cross-section of channel along the main flow direction and enhances the local convective heat transfer performance of the fin surface. Within the parameter range studied, compared to louver fins and curved vor-tex generator fins, the Num of the combined reinforced fins increased by 61.51%-91.73%, 3.45% -13.33% and 31.36% -48.53%, and f increased by 96.16%-117.22%, 2.20% -5.41% and 42.35% -56.81%, respectively. The JF value varied from 1.34 to 1.50.