Among these values, the value of the SC79 average Nusselt https://www.selleckchem.com/products/fosbretabulin-disodium-combretastatin-a-4-phosphate-disodium-ca4p-disodium.html number is in its maximum, in case of liquids containing TiO2. From Table 3, it is also clear that for the EG-based nanofluids, the value of effective RaK is larger than the water-based nanofluids, but still, the value of the average Nusselt number for water-based nanofluids is larger than that of EG-based nanofluids. It is because of the large difference in the values of skin friction coefficients.
In the case of EG-based nanofluids, the average value of skin friction coefficient is almost double than the water-based nanofluids, which decreases the average Nusselt number. From this table, it can be verified that the increase in average Nusselt number is highly dependent on the nature of base liquid rather than the nature of the nanoparticle.
Figure 9 Comparison between six different types of nanofluids. Dependence on porosity and permeability of the medium The porosity and permeability effect of the medium on the Nusselt number and skin friction coefficient is shown in Figure 10. In the simulation, the radius of the copper powder (porous media) is kept constant, and the permeability of media has been calculated for different values of porosity using the relation Figure 10 Nusselt numbers and skin friction coefficients for different values of porosity of medium for Al 2 O 3 + H 2 O at 324 K. From this figure, it is clear that, as the Temsirolimus manufacturer porosity of the medium increases, the values of average Nusselt number, local Nusselt number, average skin friction coefficient, and local skin friction coefficient Palbociclib increase. The reason for the increase in Nusselt numbers with the increase in porosity is due to the major increase in RaKeff with the increase in porosity, as given in Table 11. The reason for the increased skin friction coefficients can be explained with the help of the definition of porosity, where
it is a measure of the void spaces in a material and is a fraction of the volume of voids over the total volume. Therefore, as porosity increases, the fraction of void space increases and results in the increase in roughness of the material, and hence, it increases the skin friction for the flow. Table 11 Variation in physical properties with the porosity of medium Properties Porosity ε 0.5 0.55 0.6 0.72 K 7.4 × 10−10 1.2 × 10−9 2 × 10−9 7 × 10−9 k eff 1.7497 1.59137 1.4592 1.2167 α eff (10−7) 3.7534 3.4135 3.1301 2.6100 Preff 2.2013 2.4204 2.6396 3.1656 RaKeff 10.7041 17.5821 28.8800 101.7845 σ 0.8689 0.8820 0.8951 0.9266 T = 324, Φ =0.04, and d p = 10 nm. Conclusions In the present study, we have numerically investigated the natural convection heat transfer of nanofluids along the isothermal vertical plate embedded in a porous medium.