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Thermally developing electroosmotic flow of power-law fluids in a parallel plate microchannel

Sadeghi, A ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1016/j.ijthermalsci.2012.06.006
  3. Publisher: 2012
  4. Abstract:
  5. The present investigation considers the thermally developing electroosmotic flow of power-law fluids through a parallel plate microchannel. Both the viscous dissipation and Joule heating effects are taken into account and a step change in wall temperature is considered to represent physically conceivable thermal entrance conditions. Expressions for the dimensionless temperature and Nusselt number in the form of infinite series are presented. In general, the resultant eigenvalue problem is solved numerically; nevertheless, an analytical solution is presented for the regions close to the entrance. A parametric study reveals that increasing amounts of the Peclet number result in higher wall heat fluxes, whereas the opposite is true for the flow behavior index. Furthermore, based on the value of the dimensionless Joule heating parameter, the Nusselt number may be either an increasing or a decreasing function of the axial coordinate or even both of them in the presence of a singularity point. The viscous heating effects are also found to be negligible. Highlights: Thermally developing electroosmotic flow of power-law fluids is considered. Series solutions for temperature and Nusselt number are presented. Viscous heating effects are found to be negligible. Increasing amounts of the flow behavior index result in lower wall heat fluxes. Increasing amounts of Peclet number result in higher wall heat fluxes
  6. Keywords:
  7. Microchannel ; Power-law fluids ; Axial coordinates ; Decreasing functions ; Developing electro-osmotic flow ; Eigenvalue problem ; Electroosmotic flow ; Flow behavior index ; Infinite series ; Joule heating effect ; Parallel plates ; Parametric study ; Power law fluid ; Series solutions ; Singularity point ; Step changes ; Thermal entrance ; Viscous dissipation ; Viscous heating effects ; Wall heat flux ; Wall temperatures ; Eigenvalues and eigenfunctions ; Flow fields ; Forced convection ; Heat flux ; Joule heating ; Microchannels ; Nusselt number ; Peclet number ; Vehicular tunnels ; Viscous flow ; Electroosmosis
  8. Source: International Journal of Thermal Sciences ; Volume 61 , 2012 , Pages 106-117 ; 12900729 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S1290072912001822