Analysis of extended micro-Graetz problem in a microtube

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Avci M., AYDIN O.

SADHANA-ACADEMY PROCEEDINGS IN ENGINEERING SCIENCES, cilt.43, sa.7, 2018 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 43 Sayı: 7
  • Basım Tarihi: 2018
  • Doi Numarası: 10.1007/s12046-018-0897-8
  • Dergi Adı: SADHANA-ACADEMY PROCEEDINGS IN ENGINEERING SCIENCES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Anahtar Kelimeler: Microtube, axial conduction, Knudsen number, FLOW-HEAT-TRANSFER, PARALLEL-PLATE MICROCHANNEL, SLIP-FLOW, AXIAL CONDUCTION, VISCOUS DISSIPATION, LAMINAR-FLOW, GASEOUS SLIP, FLUID-FLOW, WALL, PIPE
  • Karadeniz Teknik Üniversitesi Adresli: Evet

Özet

In this numerical study, hydrodynamically developed but thermally developing forced convection in a microtube subjected to a step change in the wall heat flux is analysed using a finite-volume method. The slip velocity and temperature jump conditions at the wall and the axial conduction in the fluid are included in the analysis. The combined effects of the Peclet number and the Knudsen number on the local Nusselt numbers as well as on the wall and bulk temperatures are determined in the continuum and slip flow regimes (0 Kn 0.1). In the entrance region, large reductions are observed in the Nusselt number with decreasing Peclet number or increasing Knudsen number. The results also show that the thermal length increases with decreasing Peclet number.