P	Pressure (${\mathrm{ML}}^{-1}{\mathrm{T}}^{-2}$)
${\mathsf{\Phi }}_1$, ${\mathsf{\Phi }}_2$	the volume fraction of CNTs
$x,y$	Cartesian Coordinates
${\kappa }_{bf}$	Thermal conductivity of the $F{e}_3{O}_4$-nanofuid ($\mathrm{W}/(\mathrm{mK})$
u	x-axis velocity ($\mathrm{m}·{\mathrm{s}}^{-1}$)
${\mu }_{hnf}$	Viscosity of hybrid nanofluid ($\mathrm{Ns}/{\mathrm{m}}^2$)
v	y-axis velocity ($\mathrm{m}·{\mathrm{s}}^{-1}$)
${\kappa }_{hnf}$	Thermal conductivity of hybrid nanofluid ($\mathrm{W}/(\mathrm{mK})$)
${\rho }_{hnf}$	Density of hybrid nanofluid ($\mathrm{kg}/{\mathrm{m}}^3$)
$H_0$	Water
t	time ($\mathrm{s}$)
$Ha$	Hartmann number
$T_H$	Upper plate temperature ($\mathrm{K}$)
${\sigma }_{hnf}$	Electrical conductivity of hybrid nanofluid (${\mathrm{ML}}^3{\mathrm{T}}^{-3}{\mathrm{I}}^{-2}$)
$R{e}_m$	Rynold’s Magnetic Parameter
${\nu }_{hnf}$	Kinematic viscosity of hybrid nanofluid (${\mathrm{m}}^2{\mathrm{s}}^{-1}$)
$Pr$	Prandtl number ($\nu$/k)
${\mu }_f$	Dynamic viscosity (PaS)
${(\rho Cp)}_{hnf}$	Specific Heat of hybrid nanofluid (J/(kgK))
${\rho }_f$	Density ($\mathrm{kg}/{\mathrm{m}}^3$)
S	Squeezing number
$Ec$	Eckert number
$b_1,b_2$	Components of Magnetic field
$h(t)$	Distance between parallel plates (L)
$CNTs$	Carbon nanotubes
$F{e}_3{O}_4$	Ferrous-Oxide
$SWCNTs$	Single-wall carbon nanotubes
$MWCNTs$	Multi-wall carbon nanotubes