Experimental and Numerical Investigation of Micro encapsulated Phase Change Slurry in Various Micro Channel Heat Sink Configuration

Abstract

newline The encapsulated phase change slurry exhibits excellent heat transfer newlinebehavior in modern high power electronic cooling applications due to its unique newlineadvantage of latent heat transfer. The present work investigates its thermohydraulic newlineperformance in re-entrant, tortuous and rib-with-dimple configured newlinemicrochannel heat sink. The core phase change material used in this research is newlineparaffin. Shell material considered for the encapsulation of phase change newlinematerials are Silica (Si) and Titanium (Ti). The in-situ hydrolysis and newlinepolycondensation processes were used to synthesis the micro-encapsulation. The newlinemicro-encapsulated phase change slurry (MPCMS) was prepared, by dispersing newlinethe micro-encapsulated particles, at a concentration of 1% and 2% in the De- newlineIonized (DI) water. The experiments were conducted at different flow rates of newline200 400 ml/min under the laminar region of Reynolds number 400 850 with a newlineuniform heat flux of 10, 20, and 30 W/cm2 and inlet subcooling of 25°C. The newlinethermal and flow behavior of both the DI water and MPCMS in various newlineconfigured microchannels is investigated by considering the wall temperature, newlineNusselt number and pressure drop at the steady state. Furthermore, the newlineeffectiveness of the MPCMS were analyzed using the cost of performance (COP) newlineand compared among the straight, re-entrant (segmental and combined straightsegmental), newlinetortuous (wavy and zigzag) and rib-with-dimple (rib-groove and newlinedimple-cavity) configured microchannel heat sink. All the channels were newlineconfigured with a constant heat sink of length 30 mm, and hydraulic diameter 0.4 newlinemm. newlineWith the re-entrant configured microchannels comprising straight, newlinecombined straight-segmental and fully segmental channels. The experimental newlineresults demonstrate that the MPCMS of low concentration (1%) exhibits higher newlineheat transfer than DI water in all configurations. At the Reynolds number of 780 newlineand heat flux of 20W/cm2, the average Nusselt number in a parallel microchannel newlineheat sink improves by about 13.3% while using MPCMS of low Si conc