heat transfer fluid flow minichannels microchannels

[...]... constant heat flux and fully 4 Heat transfer and fluid flow in minichannels and microchannels Heat transfer coefficient (W/m2 -k) 1,000,000 100,000 Water 10,000 Air 1000 100 10 10 100 1000 10,000 Hydraulic diameter (ϭside) of a square channel (µm) Fig 1.2 Variation of the heat transfer coefficient with channel size for fully developed laminar flow of air and water developed laminar flow conditions The heat transfer. .. height, m (Chapter 7); parameter used in Eq (6.141) (Chapter 6) Heat transfer coefficient, W/m2 -K (Chapters 1, 3, 5 and 6); channel half-depth, m (Chapter 2); specific enthalpy, J/kg (Chapters 2 and 5); wave height, m (Chapter 7) Average heat transfer coefficient, W/m2 K (Chapters 3 and 6) Film heat transfer coefficient, W/m2 K (Chapter 6) Latent heat of vaporization, J/kg (Chapter 6) σ Gas-phase height in... classification scheme for defining minichannels and microchannels This classification scheme is essentially employed for ease in terminology; the applicability of continuum theory or slip flow conditions for gas flow needs to be checked for the actual operating conditions in any channel 1.3 Basic heat transfer and pressure drop considerations The effect of hydraulic diameter on heat transfer and pressure drop... in a Rayleigh–Benard convection cell, Science, 298, 793 Mehendale, S S., Jacobi, A M., and Shah, R K., Fluid flow and heat transfer at micro- and meso-scales with applications to heat exchanger design, Appl Mech Rev., 53, 175–193 This page intentionally left blank Chapter 2 SINGLE-PHASE GAS FLOW IN MICROCHANNELS Stéphane Colin Department of Mechanical Engineering, National Institute of Applied Sciences... in microchannels are detailed The main theoretical and experimental results from the literature about pressure-driven, steady or pulsed gas microflows are summarized Heat transfer in microchannels and thermally driven gas microflows are also described They are particularly interesting for vacuum generation, using microsystems without moving parts E-mail: stephane.colin@insa-toulouse.fr 9 10 Heat transfer. .. size The balance between the heat transfer rate and pressure drop becomes an important issue in designing the coolant flow passages for the high-flux heat removal encountered in microprocessor chip cooling These issues are addressed in detail in Chapter 3 under single-phase liquid cooling 1.4 Special demands of microscale biological applications The use of minichannels, microchannels, and microfluidics... manipulation of biological materials 1.5 Summary Microchannels are found in many biological systems where extremely efficient heat and mass transfer processes occur, such as lungs and kidneys The channel size classification is based on observations of many different processes, but its use is mainly in arriving at a common terminology The heat and mass transfer rates in small diameter channels are also... Evolution of microchannel flow passages – thermohydraulic performance and fabrication technology, Heat Transfer Eng., 24(1), 3–17, 2003 Kandlikar, S G and Steinke, M E., 2003, Examples of microchannel mass transfer processes in biological systems, Proceedings of 1st International Conference on Minichannels and Microchannels, Rochester, NY, April 24–25, Paper ICMM2003-1124 ASME, pp 933–943 Krishnan, M.,... (Chapters 2, 3, 5 and 6) Heat load, W (Chapter 3) Volumetric flow rate, m3 /s (Chapters 2, 3 and 7) Heat flux vector, W/m2 (Chapter 2) Heat flux, W/m2 , Chap 2; dissipated power, W (Chapter 3); constant in Eq (6.60) (Chapter 6) Volumetric flow rate per unit width, m2 /s (Chapter 7) Oxygen uptake rate on a per-cell basis, mol/s (Chapter 7) Heat flux, W/m2 (Chapters 5 and 6) Critical heat flux, W/m2 (Chapter... From an engineering standpoint, there has been a steady shift from larger diameters, on the order of 10–20 mm, E-mail: sgkeme@rit.edu; mike_king@urmc.rochester.edu 1 2 Heat transfer and fluid flow in minichannels and microchannels Compact heat exchangers Boilers Power condensers Electronics cooling Henle’s loop Tubules I Aorta 25 mm Refrigeration evaporators/ condensers Large veins and arteries 2.5 mm . Thermal and Fluid Science Fluid Abstracts: Process Engineering Fluid Dynamics Research International Communications in Heat and Mass Transfer International Journal of Heat and Fluid Flow International. y0 w0 h1" alt="" Kandlikar I044527-Prelims.tex 31/10/2005 17: 30 Page i HEAT TRANSFER AND FLUID FLOW IN MINICHANNELS AND MICROCHANNELS Kandlikar I044527-Prelims.tex 31/10/2005 17: 30 Page ii Elsevier. contact details. Kandlikar I044527-Prelims.tex 31/10/2005 17: 30 Page iii HEAT TRANSFER AND FLUID FLOW IN MINICHANNELS AND MICROCHANNELS Contributing Authors Satish G. Kandlikar (Editor and Contributing