TEHRAN (INIC)- Iranian researchers at K.N.Toosi University of Technology, examining particle sizes, showed that nanoparticles improve microcoolant performance and enhance their heat transfer.

Common coolants are generally not efficient for heat transfers more than 100w/cm² for which microcoolants should be used. One of the methods to enhance heat transfer coefficient is to increase heat conduction coefficient of fluid which is accessible by applying fluids with higher heat conduction coefficients.

Using fluids with higher heat conduction coefficients causes high pressure drops which then make them impractical. One solution is to use solid nanoparticles with high heat conduction coefficient floated in the fluids.

The researchers of K.N.Toosi University of Technology applied the prevailing equations in the mentioned nanoparticles for slip flow through microchannel by defining and studying the physical situation of problem and modeled Brownian motion of nanoparticles which has a profound effect on their movement owing to their small sizes by means of prevailing mathematical equations and applying quick search methods for determining the location of nanoparticles.

Finally, they determined the situation of nanoparticles release in their dispersion in the inlet of microchannel and dispersion of nanoparticles in the formation of a homogenous mixture.

Hossein Afshar, one of the researchers, mentioned that the effect of nanoparticles diameter and microchannel conditions on the formation of homogenous nanofluid and the resulting nanofluid heat transfer were investigated in this study, adding, "We analyzed nanoparticles in the fluid independently and examined the effect of fluid on particles by direct modeling."

The details of the present research are available at International Communications in Heat and Mass Transfer, volume 36, pages 1060 to 1066, 2009.