For nanofluid thermophysical properties calculation the equations which
are as follow offered. The effective density \(\rho_{\text{hnf}}\) and
specific heat \(c_{P,hnf}\) of the hybrid nanofluid at each
section-temperature \(\left(T_{m}\right)\) are determined using these
equations [59], where \(\phi_{1}\) and \(\phi_{2}\) are the volume
concentration of MWCNT and Al2O3nanoparticles, respectively.