Titanium dioxide nanofluids for heat transfer applications

• Thermophysical properties of TiO2/water nanofluids were measured experimentally.
• Thermal performance of tilted mesh heat pipe using TiO2/water nanofluid was studied.
• The study focused on the effect of vol. fraction,% fill charge ratio and tilt angle.
• Results show that utilization of nanofluid enhanced thermal performance of heat pipes.
• An inclination angle 45° and 60% fill charge ratio give the best thermal performance.

In recent study, the transport properties, namely the thermal conductivity and viscosity were studied experimentally for titanium dioxide nanoparticle dispersed in distilled water. The data are collected for particle volumetric concentration up to 1.0% and the temperature range of the measurements was from 10 to 60 °C. The results showed that the thermal conductivity increased with increasing volumetric concentration and also with increasing temperature. The data obtained from the measurements were compared with several existing theoretical models. However, our data do not reveal a good agreement with the classical as well as Brownian motion theoretical model. Furthermore, the effect of nanofluid on the thermal performance of heat pipes is investigated experimentally. The wall temperature distribution and the thermal resistance between evaporation and condensation section are measured and compared with those for the heat pipes using distilled water. The influence of% charge volume ratio of working fluid, inclination angle of the heat pipe and% amount of nanoparticles dispersed in distilled water on thermal performance of heat pipes are considered. It is found that the inclination of 45° and 60% charge volume ratio of working fluid corresponds to the best thermal performance of heat pipe using distilled water as well as titanium dioxide nanofluids.