Heat transfer enhancement of nanofluids

This paper presents a procedure for preparing a nanofluid which is a suspen sion consisting of nanophase powders and a base liquid. By means of the pro cedure, some sample nanofluids are prepared. Their TEM photographs are give n to illustrate the stability and evenness of suspension. The theoretical s tudy of the thermal conductivity of nanofluids is introduced. The hot-wire apparatus is used to measure the thermal conductivity of nanofluids with su spended copper nanophase powders. Some factors such as the volume fraction, dimensions, shapes and properties of the nanoparticles are discussed. A th eoretical model is proposed to describe heat transfer performance of the na nofluid flowing in a tube, with accounting for dispersion of solid particle s; (C) 2000 Elsevier Science Inc. All rights reserved.