New Bio-Inspired, Multiphase Forced Convection Cooling by ABS Plastic or Encapsulated Paraffin Beads

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Fatemeh Hassanipour ◽  
José L. Lage

Preliminary experimental results of forced convection by octadecane paraffin (encapsulating phase-change material (EPCM)) particles, acrylonitrile butadiene styrene plastic particles, or by clear (of particulates) water flowing through a heated parallel-plates channel are reported. The objective is to investigate the mixing effect of the particles vis-à-vis the latent heat effect. The particle concentration is kept at 3% in volume. The results, in terms of surface-averaged channel temperature and heat transfer coefficient for different fluid speed and heat-flux, indicate the mixing effect to account from 19% to 68% of the heat transfer enhancement produced by using EPCM particles. Hence particle mixing, even at a very low particle concentration, is an effective convection mechanism.

Author(s):  
Deepak Khurana ◽  
Sudhakar Subudhi

Abstract The present paper deals with the forced convection of Al2O3/water and TiO2/water nanofluids with the variation of pH and addition of surfactant in nanofluids. The aim of this study is to investigate the effect of suspension stability on the heat transfer and pressure drop characteristics of nanofluids. The present experimental set up is same as used by our earlier paper [1]. The suspension stability of nanofluids is improved by varying pH of nanofluids. The pH in this study is varied from 3.5±0.2 to 12.5±0.2. Addition of surfactants is employed to improve the suspension stability of nanofluids. The SDS (sodium dodecyl sulfate) surfactant of 0.05 wt % is used to increase the stability of nanofluids in the present study. It is observed that by increasing the suspension stability with the variation of pH and addition of surfactant, the heat transfer characteristics have improved appreciably. The maximum enhancement in heat transfer is obtained with TiO2/water nanofluids at a particle concentration of 0.1 vol % and a pH of 3.5±0.2.


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