微细光滑管内可压缩流动换热特性的数值研究  

Numerical study of heat transfer characteristics for compressible fluid flow in smooth microtubes

作　　者：杜东兴[1] 李志信[1] 过增元[1] 岳敏[1] 

机构地区：[1]清华大学工程力学系,北京100084

出　　处：《清华大学学报（自然科学版）》2000年第11期19-22,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金重大项目!(5 9995 5 5 0 - 2 )

摘　　要：微细通道内的可压缩流动换热特性研究是一个新兴的研究领域。利用数值方法讨论了压力功和粘性耗散对微细光滑管内可压缩流动换热特性的影响 ,得出以下结论 :微细管内 Ec沿管长是变化的 ,仅依据入口处的 Ec对压力功及粘性耗散的作用进行取舍是不确切的 ;等热流及等壁温换热条件下的计算结果显示 ,在入口 Ma及长径比较大时 ,考虑压力功及粘性耗散时得出的 N u要小于常规尺度管的理论值 ,在等壁温情况下 。The characteristics of microscale heat transfer have been an important subject of many recent investigations. Numerical simulations were carried out to study the effect of reversible work and viscous dissipation on the heat transfer characteristics of compressible fluid flow in microtubes. The results show that the dimensionless Eckert number is not constant along the microtube and, therefore, the inlet Eckert number is no longer an appropriate criterion to determine the magnitude of the reversible work and viscous dissipation. At comparatively high inlet Mach numbers and large length diameter ratios, the Nusselt numbers for constant wall temperature and constant heat flux in microtubes are substantially less than those in conventional tubes. In addition, the peculiar phenomenon of alternating heat flow direction is observed for constant wall temperature conditions.

关 键 词：微细光滑管 可压缩流动 粘性耗散 换热特性 

分 类 号：TK124[动力工程及工程热物理—工程热物理]