Influence of nanoparticles concentration

Reynolds number and heat flux on the convective heat transfer performance of MWNTs/H2O water-based nanofluid were investigated experimentally. The concentration of nanoparticles was 0.05 g/L

0.1 g/L

0.2 g/L and 0.4 g/L. The Reynolds number was changed from 500 to 900. The heat flux was changed from 10 kW/m2 to 20 kW/m2. The result indicated that

first

the convective heat transfer coefficient of nanofluids increases with increasing nanoparticles concentration

Re and heat flux. For example

the convection heat transfer coefficient of nanofluids is increased by 17.6% than base fluid when the Reynolds number is 631 and the concentration of nanoparticles is 0.4 g/L. Then

the rise of convection heat transfer coefficient of nanofluids is significantly higher than that of thermal conductivity. The convection heat transfer coefficient and the thermal conductivity of nanofluids is increased by 7.4% and 0.15%

respectively

than base fluid when the concentration of nanoparticles is 0.05 g/L. The convective heat transfer coefficient and thermal conductivity compared with base fluids is increased by 7.4% and 0.15%

respectively. Finally

an appropriate experimental correlation of mixed convection heat transfer is built on the basis of the Eubank-Proctor equation at the low Reynolds number.