Silver/oil Nanofluids in Heat Exchanger An Experimental Study on Convective Heat Transfer

In present work, we used two sizes of silver (Ag) nanoparticles (NPs) with different particle loadings and dispersed them into oil to make nanofluids. The silver/oil nanofluid with different nanoparticles weight fractions of 0.5%, 1% and 2% was prepared by ultrasonic device in two step method. The measurements of heat transfer coefficients were performed. An up to 30% enhancement of the heat transfer coefficient was observed in the laminar flow regime. The heat transfer coefficient is shown to increase with increasing Reynolds number. In addition, the heat transfer coefficient decreased with increasing fluid temperature. A constant downward trend of enhancement ratio with respect to Reynolds number was specified for the nanofluids discussed in this study.