摘要
通过试验和数值模拟方法对一种带突起内翅片管内的对流换热特性进行了研究,并与直内翅片管的流动与传热特性进行了对比,实验表明带突起内翅片管的换热特性优于直内翅片管,起到了强化传热的作用,但同时其流动阻力相应增加。应用可实现k-ε两方程湍流模型,模拟了带突起内翅片管内的流动与传热过程,计算结果与实验结果符合良好。结果表明:翅片管内周期性的突起改变了其内部流场及温度场的分布情况,相对于直内翅片管而言,产生了有利于强化换热的二次涡流,对流动边界层起到了一定的破坏作用,同时增加了其流场的湍动能,提高了换热壁面附近的温度梯度,强化了传热。
Through experiments and numerical simulation methods a study has been conducted of the characteristics of convection heat exchange of ridged internal-finned tubes and a comparison of the above characteristics with the flow and heat transfer characteristics of straight internal-finned tubes performed.The experimental results indicate that the heat exchange characteristics of ridged internal-finned tubes are better than those of straight internal-finned tubes in terms of intensified heat transfer performance,but at the same time there is a corresponding increase in flow resistance.Through the adoption of a turbulent flow model capable of realizing k-ε equation,the flow and heat transfer process of ridged internal-finned tubes have been simulated.The calculation results are in good agreement with the experimental ones.The calculation results indicate that the periodical ridges inside the finned tubes have changed the distribution of the inner-flow fields and temperature ones.Relative to the straight internal-finned tubes a secondary vortex flow has emerged,which is conducive to an intensified heat exchange and plays a definite destructive role to the flow boundary layer.Meanwhile,by increasing the turbulent kinetic energy of the flow field,the temperature gradient in the neighborhood of the heat exchange wall surfaces has been enhanced,contributing to an intensification of heat transfer.
出处
《热能动力工程》
CAS
CSCD
北大核心
2006年第3期283-286,共4页
Journal of Engineering for Thermal Energy and Power
基金
教育部霍英东教育基金会高等院校青年教师基金资助项目(91056)
关键词
突起内翅片管
强制对流
传热特性
强化传热
二次涡流
ridged internal-finned tube,forced convection,heat transfer characteristics,intensified heat transfer,secondary vortex flow
