A Thermal Conductivity Model for Nanofluids Heat Transfer Enhancement

Nanofluids may be used for better cooling of drilling bits, especially poly crystalline diamond compact bits, which are very temperature sensitive. The study on the modeling of energy transport in nanofluids divided the heat transfer in nanofluids into two portionsheat transferred by stationary particles and heat transferred by moving particles. The authors studied each portion together. An equation for the thermal conductivity of nanofluids was developed based on the nanolayer thickness, Brownian Motion, and the size distribution of the nanoparticles. The expression developed successfully explained the enhanced thermal conductivity of nanofluids and led to some important conclusions. The authors investigated the size distribution of nanoparticles, which has been suggested to be an important factor and it gave satisfactory results. The values of the thermal conductivity for CuO/water and TiO2/water nanofluids were calculated using the expression developed from this study and they agreed very well with published experimental data.