Table 1 Mathematical formulations of the thermophysical properties of \({C}_{2}{H}_{6}{O}_{2}-A{l}_{2}{O}_{3}\) and \(Cu-{Al}_{2}{O}_{3}/{C}_{2}{H}_{6}{O}_{2}\)39.
Properties | Nanofluid (\({Al}_{2}{O}_{3}-{H}_{2}O\)) | Hybrid nanofluid (\(Cu-{Al}_{2}{O}_{3}/{H}_{2}O\)) |
|---|---|---|
Viscosity | \({\mu }_{nf}=\frac{{\mu }_{f}}{{\left(1-\varphi \right)}^{2.5}}.\) | \({\mu }_{hnf}=\frac{{\mu }_{f}}{{{\left(1-{\phi }_{1}\right)}^{2.5}\left(1-{\phi }_{2}\right)}^{2.5}}\), |
Electrical conductivity | \(\frac{{\sigma }_{nf}}{{\sigma }_{f}}=1+\frac{3\left(\sigma -1\right)\phi }{\left(\sigma +2\right)-\left(\sigma -1\right)\phi }\), | \(\frac{{\sigma }_{hnf}}{{\sigma }_{bf}}=\frac{{\sigma }_{{s}_{2}}+2{\sigma }_{bf}-2{\phi }_{2}\left({\sigma }_{bf}-{\sigma }_{{s}_{2}}\right)}{{\sigma }_{{s}_{2}}+2{\sigma }_{bf}+{\phi }_{2}\left({\sigma }_{bf}-{\sigma }_{{s}_{2}}\right)}\), where, \(\frac{{\sigma }_{bf}}{{\sigma }_{f}}=\frac{{\sigma }_{{s}_{1}}+2{\sigma }_{f}-2{\phi }_{1}\left({\sigma }_{f}-{\sigma }_{{s}_{1}}\right)}{{\sigma }_{{s}_{1}}+2{\sigma }_{f}+{\phi }_{1}\left({\sigma }_{f}-{\sigma }_{{s}_{1}}\right)}\), |
Heat capacity | \({\left(\rho {C}_{p}\right)}_{nf}=\varphi {\left(\rho {C}_{p}\right)}_{s}+\left(1-\varphi \right){\left(\rho {C}_{p}\right)}_{f}.\) | \({\left(\rho {C}_{p}\right)}_{hnf}={\left(\rho {C}_{p}\right)}_{f}\left(1-{\phi }_{2}\right)\left\{1-{\phi }_{1}+{\phi }_{1}{\left(\rho {C}_{p}\right)}_{{s}_{1}}\right\}+{\phi }_{2}{\left(\rho {C}_{p}\right)}_{{s}_{2}}\) |
Density | \({\rho }_{nf}=\varphi {\rho }_{s}+\left(1-\varphi \right){\rho }_{f}\) | \({\rho }_{hnf}={\rho }_{f}\left(1-{\phi }_{2}\right)\left\{1-{\phi }_{1}+{\phi }_{1}{\rho }_{{s}_{1}}\right\}+{\phi }_{2}{\rho }_{{s}_{2}}\), |
Thermal conductivity | \(\frac{{k}_{nf}}{{k}_{f}}=\frac{\left(\frac{{k}_{s}}{{k}_{f}}+2\right)-2\varphi \left(1-\frac{{k}_{s}}{{k}_{f}}\right)}{\left(\frac{{k}_{s}}{{k}_{f}}+2\right)+\varphi \left(1-\frac{{k}_{s}}{{k}_{f}}\right)}.\) | \(\frac{{k}_{hnf}}{{k}_{bf}}=\frac{{k}_{{s}_{2}}+\left(n-1\right){k}_{bf}-\left(n-1\right){\phi }_{2}\left({k}_{bf}-{k}_{{s}_{2}}\right)}{{k}_{{s}_{2}}+\left(n-1\right){k}_{bf}+{\phi }_{2}\left({k}_{bf}-{k}_{{s}_{2}}\right)}\), Where, \(\frac{{k}_{bf}}{{k}_{f}}=\frac{{k}_{{s}_{1}}+\left(n-1\right){k}_{f}-\left(n-1\right){\phi }_{1}\left({k}_{f}-{k}_{{s}_{1}}\right)}{{k}_{{s}_{1}}+\left(n-1\right){k}_{f}+{\phi }_{1}\left({k}_{f}-{k}_{{s}_{1}}\right)}\), |