Analysis of evaporating mist flow for enhanced convective heat transfer

Abstract

a b s t r a c tEnhancement 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.

The use of CFD for predicting and optimizing the performance of air conditioning equipment

“…An increase in heat transfer was obtained. Similar findings were also reported by Kumari et al [6]. Alizadehdakhel et al [7] studied experimentally and numerically the simultaneous evaporation and condensation phenomena in a thermosyphon.…”

“…Whereas many studies appeared in the literature dealing with heat transfer enhancement in heat exchange equipment [1][2][3][4][5][6][7][8], the use of computational fluid dynamics (CFD) for predicting the performance of air conditioning units is limited to few investigations. Lorenzini and Moretti [1] studied numerically the combined geometrical and thermo-fluid mechanical effects on fin optimization to enhance heat removal.…”

Conjugate heat transfer analysis of leading edge and downstream mist–air film cooling on turbine vane

“…Recently, Ragab and Wang [12] presented a numerical study to investigate the feasibility of transporting mist through the internal cooling channel in high-pressure turbine vanes for film cooling over the vane's surface. Kumari et al [13] underscores the importance of detailed numerical analyses for the performance prediction and optimization of mist-based systems. The heat transfer results from the present work highlight the promise of mist cooling for high-heat-flux thermal management; the present simulations indicate that the heat sink thermal resistance can be reduced by up to 97% upon replacing air flow with an evaporating mist flow.…”

Droplet retention on an incline

“…Droplets are widely encountered in various cooling applications, such as mist cooling [1,2], spray cooling [3,4], and even in traditional air conditioning and refrigeration applications involving dropwise condensation [5].…”