ABSTRACT
The conventional method for enhancing heat transfer in a thermal system consists of increasing the heat transfer surface area as well as the flow velocity of the working fluid. This chapter surveys heat transfer in nanofluids. It summarizes and analyzes the theories regarding heat transfer mechanisms in nanofluids, and discusses the effects of clustering on thermal conductivity. The heat transfer associated with conduction is presented through various experiments followed by a discussion of the theories developed. There is research currently being performed on the manipulation of the properties governing the thermal conductivity of nanofluids—the particle size, shape, and surface area. Other factors that affect heat transfer are the material of the nanoparticle, particle volume concentration, and the fluid used. Nanoparticles can be produced by either physical or chemical means. Current physical processes include mechanical grinding and the inert-gas-condensation technique pioneered by Granqvist and Buhrman.
