Table 1.

Mathematical models and related boundary conditions

Airflow model	Incompressible fluid and laminar flow	$\mathrm{\nabla }.\mathbf{u}=\mathbf{0}$ (1) ${\rho }_{\mathbf{a}}\frac{\partial \mathbf{u}}{\partial t}+{\rho }_{\mathbf{a}}\left(\mathbf{u}.\mathrm{\nabla }\mathbf{u}\right)=-\mathrm{\nabla }P+\mathrm{\nabla }.\left[{\mu }_{\mathrm{a}}\left(\mathrm{\nabla }\mathbf{u}+{\left(\mathrm{\nabla }\mathbf{u}\right)}^{\mathrm{T}}\right)\right]$ (2)
	Reynolds number	Inside the packages: 54 At the inlet: 710
	Boundary conditions	Inlet: p = p 0 Wall: u = 0 Outlet: u = u 0 Interface: u = 0
	Airflow rate	0.4 L s−1 kgp −1
	Air properties	Similar to those of dry air at 0°C
	Transient heat transfer	${\rho }_{\mathrm{a}}C{p}_{\mathrm{a}}\frac{\partial T_{\mathrm{a}}}{\partial t}+{\rho }_{\mathrm{a}}C{p}_{\mathrm{a}}\left(\mathbf{u}.\mathrm{\nabla }{T}_{\mathrm{a}}\right)=\mathrm{\nabla }.\left(k_{\mathrm{a}}\mathrm{\nabla }{T}_{\mathrm{a}}\right)$ (3)
Heat transfer within the fluid domain	Boundary conditions	Inlet: T a = T a0 Outlet: $\left(-k_{\mathrm{a}}\mathrm{\nabla }{T}_{\mathrm{a}}\right)\mathbf{n}=0$ Wall: $\left(k_{\mathrm{a}}\mathrm{\nabla }{T}_{\mathrm{a}}\right)\mathbf{n}=0$ Interface: Ta = Tp Symmetry plane: $\left(k_{\mathrm{a}}\mathrm{\nabla }{T}_{\mathrm{a}}\right)\mathbf{n}=0$
	Air properties	Similar to those of dry air at 0°C
	Transient heat transfer	${\rho }_{\mathrm{p}}C{\mathrm{p}}_{\mathrm{p}}\frac{\partial {\mathrm{T}}_{\mathrm{p}}}{\partial \mathrm{t}}=\mathrm{\nabla }.\left({\mathrm{k}}_{\mathrm{p}}\mathrm{\nabla }{\mathrm{T}}_{\mathrm{p}}\right)$ (4)
Heat transfer in the strawberries domain	Boundary conditions	$\left(k_{\mathrm{P}}\mathrm{\nabla }{T}_{\mathrm{P}}-k_{\mathrm{a}}\mathrm{\nabla }{T}_{\mathrm{a}}\right)\mathbf{n}=0$ (5)
	Strawberry properties	k p = 0.57 wm−1°C−1 C p, p = 3.95 kJ/kg °C ρ p = 800 kg/m3
	Initial temperature	16°C
	Assumption	No moisture loss during the cooling

In the above equations, C_p and ρ denote the specific heat capacity and density, respectively u and P represent the air velocity and pressure, respectively; k is thermal conductivity; and T shows the temperature. Subscripts a and p indicate the air and the product, respectively.