NUSSELT NUMBER AND CONVECTION HEAT TRANSFER COEFFICIENT FOR A COAXIAL HEAT EXCHANGER USING Al^sub 2^O^sub 3^-WATER pH=5 NANOFLUID

Recently, a new class of fluid made up of metal nano-particles in suspension in a liquid, called nanofluid, appeared. Some numerical studies have shown that these new fluids have a higher heat transfer performance, compared with the conventional liquids. In the present study, we have attempted to study, by experimentation, the thermal performances of a particular nanofluid composed of aluminum oxide (γAl^sub 2^O^sub 3^) particles dispersed in water for various concentrations ranging from 0 to 4%. The experimental set up is a coaxial exchanger, which is destined to solar application, in which the heating liquid used is the nanofluid studied. [PUBLICATION ABSTRACT]