Figure 11 Comparison of thermal
conductivity enhancement of SiO2/60EGW and
SiO2/40EGW nanofluids
It is pretty clear that SiO2/40EGW shows an enhancement
in thermal conductivity with a maximum enhancement of 34% than the base
fluid at 1.5% volume concentration and 55oC
temperature. On the other hand, the thermal conductivity of
SiO2/60EGW shows an enhancement of 28% at 1.5% volume
concentration and 55oC temperature. The reason of
thermal conductivity enhancement is with the Brownian motion and
micro-convection of particles in the base fluids. The thermal
conductivity enhancement not only depends on the particle concentration
and temperature, but it also depends on the effect of base fluid.
Based on the regression analysis, the theoretical predictions were made
for thermal conductivity of SiO2 and
Al2O3 nanoparticles in both the base
fluids and are shown plotted in Figure 12 . At a concentration
1.5%, Al2O3/40EGW predicts a higher
thermal conductivity when compared to other nanofluids. At the same
concentration Al2O3nanoparticles and
40EGW based nanofluids predicts a higher thermal conductivity values
when compared to SiO2 nanoparticles and 60EGW based
nanofluids respectively.