Analysis of evaporating mist flow for enhanced convective heat transfer

• Published in: International journal of heat and mass transfer Vol. 53; no. 15; pp. 3346 - 3356
• Main Authors: Kumari, Niru, Bahadur, Vaibhav, Hodes, Marc, Salamon, Todd, Kolodner, Paul, Lyons, Alan, Garimella, Suresh V
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2010; Elsevier
• Subjects: Applied sciences; Computer simulation; Design. Technologies. Operation analysis. Testing; Droplets; Electronics; Energy; Energy. Thermal use of fuels; Evaporation; Exact sciences and technology; Heat sinks; Heat transfer; Heat transfer enhancement; Inlets; Integrated circuits; Mathematical models; Mist flow; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Theoretical studies. Data and constants. Metering; Thermal management; Transport equations; Two-phase flow; Heat transfer enhancement; Thermal management; Mist flow; Two-phase flow; Relative humidity; Forced convection; Two phase flow; Evaporation; Heat transfer coefficient; Droplet; Modeling; Electronic component; Cooling system; Numerical simulation; Heat sink; Heat transfer
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2010.02.027

Enhancement of forced convective heat transport through the use of evaporating mist flow is investigated analytically and by numerical simulation. A two-phase mist, consisting of finely dispersed water droplets in an airstream, is introduced at the inlet of a longitudinally-finned heat sink. The latent heat absorbed by the evaporating droplets significantly reduces the sensible heating of the air inside the heat sink which translates into higher heat-dissipation capacities. The flow and heat transfer characteristics of mist flows are studied through a detailed numerical analysis of the mass, momentum and energy transport equations for the mist droplets and the airstream, which are treated as two separate phases. The coupling between the two phases is modeled through interaction terms in the transport equations. The effects of inlet mist droplet size and concentration on the thermal performance of the heat sink are analyzed parametrically. The results provide insight into the complex transport processes associated with mist flows. The simulations indicate that significantly higher heat transfer coefficients are obtained with mist flows as compared to air flows, highlighting the potential for the use of mist flows for enhanced thermal management applications.