In this paper, we present the numerical method for explaining the cooling performance of a microchannel heat sink with carbon nanotubes (CNTs)-fluid suspensions. Here we will show that with increase of nanolayer thickness of multiwalled carbon nanotubes (MWCNTs) the microchannel heat sink temperature gradient will be decreased. By using a theoretical model for explaining the enhancement in the effective thermal conductivity of nanotubes (cylindrical shape particles) for use in nanotubein- fluid suspension, we investigate the temperature contours and thermal resistance of a microchannel heat sink with MWCNTs (with *25 nm diameter) dispersed in water.
