Buoyancy effects on gaseous slip flow in a vertical rectangular microchannel

Sadeghi, M ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1007/s10404-013-1188-7
  3. Abstract:
  4. Consideration is given to the buoyancy effects on the fully developed gaseous slip flow in a vertical rectangular microduct. Two different cases of the thermal boundary conditions are considered, namely uniform temperature at two facing duct walls with different temperatures and adiabatic other walls (case A) and uniform heat flux at two walls and uniform temperature at other walls (case B). The rarefaction effects are treated using the firstorder slip boundary conditions. By means of finite Fourier transform method, analytical solutions are obtained for the velocity and temperature distributions as well as the Poiseuille number. Furthermore, the threshold value of the mixed convection parameter to start the flow reversal is evaluated. The results show that the Poiseuille number of case A is an increasing function of the mixed convection parameter and a decreasing function of the channel aspect ratio, whereas its functionality on the Knudsen number is not monotonic. For case B, the Poiseuille number is decreased by increasing each of the mixed convection parameter, the Knudsen number, and the channel aspect ratio
  5. Keywords:
  6. Knudsen number ; Microchannel ; Mixed convection parameter ; Aspect ratio ; Boundary conditions ; Buoyancy ; Heat flux ; Microchannels ; Channel aspect ratios ; Decreasing functions ; Finite Fourier transform ; Knudsen numbers ; Rectangular microchannels ; Slip boundary conditions ; Slip flow ; Thermal boundary conditions ; Mixed convection
  7. Source: Microfluidics and Nanofluidics ; Vol. 16, issue. 1-2 , 2014 , pp. 207-224 ; ISSN: 16134982
  8. URL: http://link.springer.com/article/10.1007%2Fs10404-013-1188-7