摘要

Researchers searching for new cooling medium do not limit themselves to liquids alone. Suspension in common fluids with particles in the order of nanometers (typically 10-100 nm) in size is called 'nano-fluids'. Cooling techniques are one of the vital points in industries and the way to develop the traditional fluids to a high thermal heat transfer fluid is crucial. Development of high thermal fluid as a nanofluid purely depends on the thermal and physical properties of base fluid and the particles dispersed in it and some other factors such as particle shape, particle size and the particle concentration. This paper explains the thermal properties of nanofluid, viz., thermal conductivity, specific heat and other thermal properties. An empirical correlation has been developed to predict the heat flux for nucleate pool boiling of nanofluids considering the effects of temperature, volume fraction and shape of the particle while neglecting Brownian motion of the nanoparticle, cluster/particle agglomeration and the development of the liquid layer over the plate surface. The predicted result has been compared with the Rohsenow equation and the experimental data of other investigators show a good agreement with the predicted data. Using this equation, heat transfer coefficient and heat transfer enhancement ratio of the nucleate pool boiling of Al2O3-water and TiO2-water nanofluids have been calculated. This enhanced thermophysical and heat transfer characteristics of the developed fluid dispersed with nanoparticles can be used for high heat transfer medium for future applications.

  • 出版日期2014-6