Single-Phase Gaseous Flows Microchannels

Single-Phase Gaseous Flows in Microchannels, Fig.1 Flow regimes identified by the Knudsen number... 

FLOW REGIMES IN MICROCHANNEL SINGLE-PHASE GASEOUS FLUID FLOW... 

Bayazitoglu, Y., and Kakac, S., (2005) Flow Regimes in MicroChannel Single-Phase Gaseous Fluid Flow, Microscale Heat Transfer-Fundamentals and Applications, S. Kakae (ed.), Kluwer Academie Publishers, Dordrecht (This publication). 

The scientific program starts with an introduction and the state-of-the-art review of single-phase forced convection in microchannels. The effects of Brinkman number and Knudsen numbers on heat transfer coefficient is discussed together with flow regimes in microchannel single-phase gaseous fluid flow and flow regimes based on the Knudsen number. In some applications, transient forced convection in microchannels is important. 

Bayazitoglu Y, Kakac S (2005) Flow regimes in microchannel single-phase gaseous fluid flow. In Kakac S, Vasiliev L, Bayazitoglu Y, Yener Y (eds) Microscale heat transfer-fundamentals and applications. Kluwer Academic Publishers, The Netherlands... 

Discrepancy between the conventional theory and the microchannel measurements of friction factor/ in gaseous flow has been attributed to compressibility [6]. In general it appears that/Re for compressible slip flow is less than that for the incompressible case [3]. In a comprehensive study of results of microscale single-phase internal flows [1], it has been found that the only definitive conclusion that can be reached from the currently available data is that gaseous slip flow data indicate an approximate 60% reduction in / compared to macroscale theory at the same Re (while for laminar non-slip water flow/ appears to be approximately 20% higher than the theoretical predictions). The finding for compressible slip flow seems to be supported by a simple analytical correlation with the factor c 0.6 0.05 [3] ... 

The subject of this chapter is single-phase heat transfer in micro-channels. Several aspects of the problem are considered in the frame of a continuum model, corresponding to small Knudsen number. A number of special problems of the theory of heat transfer in micro-channels, such as the effect of viscous energy dissipation, axial heat conduction, heat transfer characteristics of gaseous flows in microchannels, and electro-osmotic heat transfer in micro-channels, are also discussed in this chapter. 

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