Table 2.

Thermophysical features of simple nanofluids and hybrid nanofluid.

Properties	Pure nanofluid	Hybrid nanofluid
Density	${\rho }_{nf}=\left(1-\phi \right){\rho }_f+\phi {\rho }_s$	${\rho }_{hnf}={\phi }_2{\rho }_{s2}+\left\{\left(1-{\phi }_2\right)\left[\left(1-{\phi }_1\right){\rho }_f+{\phi }_1{\rho }_{s1}\right]\right\}$
viscosity	${\mu }_{nf}=\frac{{\mu }_f}{{\left(1-\phi \right)}^{2.5}}$	${\mu }_{hnf}=\frac{{\mu }_f}{{\left(1-{\phi }_1\right)}^{2.5}{\left(1-{\phi }_2\right)}^{2.5}}$
Thermal conductivity	$\frac{k_{nf}}{k_f}=\frac{k_s-\phi \left(k_f-k_s\right)+\left(n-1\right)k_f}{k_s+\phi \left(k_f-k_s\right)+\left(n-1\right)k_f}$	$\frac{k_{hnf}}{k_{bf}}=\frac{k_{s2}-\left(n-1\right){\phi }_2\left(k_{bf}-k_{s2}\right)+\left(n-1\right)k_{bf}}{k_{s2}+{\phi }_2\left(k_{bf}-k_{s2}\right)+\left(n-1\right)k_{bf}}$ where $\frac{k_{nf}}{k_f}=\frac{k_{s1}-{\phi }_1\left(k_f-k_{s1}\right)+\left(n-1\right)k_f}{k_{s1}+{\phi }_1\left(k_f-k_{s1}\right)+\left(n-1\right)k_f}$
Electric conductivity	$\frac{{\sigma }_{nf}}{{\sigma }_f}=1+\frac{3\phi \left(\sigma -1\right)}{\left(\sigma +2\right)-\phi \left(\sigma -1\right)}$ where $\sigma =\frac{{\sigma }_s}{{\sigma }_f}$	$\frac{{\sigma }_{hnf}}{{\sigma }_{bf}}=\frac{{\sigma }_{s2}-2{\phi }_2\left({\sigma }_{bf}-{\sigma }_{s2}\right)+2{\sigma }_{bf}}{{\sigma }_{s2}+{\phi }_2\left({\sigma }_{bf}-{\sigma }_{s2}\right)+2{\sigma }_{bf}}$ where $\frac{{\sigma }_{bf}}{{\sigma }_f}=\frac{{\sigma }_{s1}-2{\phi }_2\left({\sigma }_f-{\sigma }_{s1}\right)+2{\sigma }_f}{{\sigma }_{s1}+{\phi }_2\left({\sigma }_f-{\sigma }_{s1}\right)+2{\sigma }_f}$