ABSTRACT
The thermal performance of cylindrical heat pipes utilizing a nanofluid as the working fluid has been investigated. Three of the most common nanoparticles, namely Al2O3, CuO, and TiO2, are considered. The heat pipe velocity, pressure, temperature, and maximum heat transfer limit are obtained for different nanoparticle concentration levels and sizes. Moreover, the possibility of reducing the size of the cylindrical heat pipe by utilizing nanofluids is studied. The results from our model confirm previous experimental results, i.e., the thermal performance of a heat pipe is improved and temperature gradient along the heat pipe and thermal resistance across the heat pipe are reduced when nanofluids are utilized as the working fluid. It is shown that the thermal resistance decreases as the concentration increases or as the particle diameter decreases. The influence of nanofluid and the geometrical characteristics of the wick on the maximum heat load carrying capability of the cylindrical heat pipe is investigated in this chapter.
