Mixed Convection in a Vertical Microannulus Between Two Concentric Microtubes


Avci M. , AYDIN O.

JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME, cilt.131, 2009 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 131 Konu: 1
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1115/1.2977552
  • Dergi Adı: JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME

Özet

In this study, fully developed mixed convective heat transfer of a Newtonian fluid in a vertical microannulus between two concentric microtubes is analytically investigated by taking the velocity slip and the temperature jump at the wall into account. The effects of the mixed convection parameter Gr/Re, the Knudsen number Kn, and the aspect ratio r(*) on the microchannel hydrodynamic and thermal behaviors are determined. Finally, a Nu=f(Gr/Re,Kn,r(*)) expression is developed. It is disclosed that increasing Gr/Re enhances heat transfer while rarefaction effects considered by the velocity slip and the temperature jump in the slip flow regime decreases it. [DOI: 10.1115/1.2977552]