摘要
针对一种新型的外凸式波节管结合内插扭带(CT)的流动与传热特性进行了RNGk-ε数值模拟研究。数值结果与实验结果进行了对比,验证了数值模型的精确性。将CT和传统的光管结合内插扭带(ST)的流动与传热特性进行了对比研究,揭示了其复合强化换热机理。结果表明CT相比于传统的ST,传热性能以及综合传热性能最多分别提高1.48和1.3倍,并且在低Reynolds数时提高得更加明显。CT在波节与扭带的间隙区域形成了脱体涡旋,破坏了近壁面的热边界层,同时扭带增加了主流区的扰动,使得湍动能增加,因此波节和扭带的协同作用使管内达到了复合强化换热效果。
The flow and heat transfer characteristic in outward convex corrugated tube combined with insert twisted tube(CT)was numerically studied based on the three-dimension RNG k-ε model.A comparison is proposed between the numerical results and experimental results in order to check the reliability of numerical model.Comparative study on flow and heat transfer between the CT and conventional smooth tube(ST)is performed in order to review the compound heat transfer enhancement mechanism.The results show that compared with ST,the heat transfer performance and overall heat transfer performance of CT increase by 1.48 and 1.3respectively,and more obvious in the low Reynolds number.Detached vortex is formed between the corrugatoion and twisted tape in CT,breaking the thermal boundary layer.Disturbance is increased by twisted tape in the main flow region,meanwhile,turbulence kinetic energy increase.Therefore,compound heat transfer enhancement is achieved by synergistic effect between the corrugation and twisted tape.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2016年第S1期195-202,共8页
CIESC Journal
基金
国家自然科学基金项目(51506034)~~
关键词
外凸式波节管结合内插扭带
RNGk-ε
复合强化换热
综合传热性能
outward convex corrugated tube combined with twisted insert
RNG k-ε
compound heat transfer enhancement
overall heat transfer performance
