investigation and comparison the effect of different nanofluids on heat pipe thermal performance

Heat pipe is an effective device for heat transferring that using nanofluid، which is prepared by dispersion of nanoparticles in a base fluid، is a way to enhance its thermal performance. In this work، thermal performance of a cylindrical heat pipe while using different nanofluids is simulated numerically. Three kinds of the used nanofluids are consist of aluminium oxide، copper oxide and silver nanoparticles in water base fluid. The effects of variation of the nanoparticles، particle volume fractions and the size of nanoparticles on thermal performance، pressure and velocity distribution in heat pipe are investigated and the results are compared with each other and with that of the pure water. The used nanoparticles in base fluid cause the heat pipe thermal performance to increase in comparison with pure water، such as 12. 27%، 12. 32% and 13. 26% reduction in thermal resistance and temperature gradient along the heat pipe for 3% particle volume fraction and particle diameter of 20 nm for aluminium oxide، copper oxide and silver nanoparticles are observed respectively. It is found that the particles with smaller size have more effect on temperature gradient along the heat pipe. Also optimum amount of particle volume fraction and size of particles for heat pipe performance increment are established.