Effect of variable thermal conductivity and viscosity on single phase convective heat transfer in slip flow


KAKAÇ S., GÜVENÇ YAZICIOĞLU A., Gozukara A. C.

HEAT AND MASS TRANSFER, cilt.47, sa.8, ss.879-891, 2011 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 47 Sayı: 8
  • Basım Tarihi: 2011
  • Doi Numarası: 10.1007/s00231-011-0851-3
  • Dergi Adı: HEAT AND MASS TRANSFER
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.879-891
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

For a variety of fields in which micro-mechanical systems and electronic components are used, fluid flow and heat transfer at the microscale needs to be understood and modeled with an acceptable reliability. In general, models are prepared by making some extensions to the conventional theories by including the scaling effects that become important for microscale. Some of these effects are; axial conduction, viscous dissipation, and rarefaction. In addition to these effects, temperature variable thermal conductivity and viscosity may become important in microscale gas flows due to the high temperature gradients that may exist in the fluid. For this purpose, simultaneously developing, single phase, laminar and incompressible air flow in a microtube and in the micro gap between parallel plates is numerically analyzed. Navier-Stokes and energy equations are solved and the variation of Nusselt number along the channel is presented in tabular and graphical forms as a function of Knudsen, Peclet, and Brinkman numbers, including temperature variable thermal conductivity and viscosity.