A	total cross-sectional area of a basic unit
A ci	cross-sectional area of the honeycomb core in the i-th layer
A fi	cross section area of the panel in the i-th layer
A S	cross-sectional area of the solid heat conduction path
Ak	radiation surface area of cell k
c p,m	mass specific heat capacity of cell m
d	inner tangent circle diameter of the honeycomb core
$G_{\mathrm{k},\mathrm{m}}$	net radiation coefficient
h	plate thickness/thickness of basic unit
h ci	thickness of i-th layer
l a,b	distance from the center of cell b to cell a
m m	mass of cell m
n	number of stacked layers
Q	total heat flow
Q a	convection heat flow
q a	heat flux of entrapped air
Q f	radiation heat flow
q f	radiation heat flux
Q s	conduction heat flow
q s	conduction heat flux
ΔQf−m	radiative heat flow of cell m
ΔQs−m,n	conductive heat flow from cell n to cell m
ΔTm	temperature change of cell m
R equ	equivalent thermal resistance
R ci	equivalent thermal resistance of the honeycomb core in the i-th layer
R fi	equivalent thermal resistance of the panel in the i-th layer
T m	temperature of cell m
T Hi	temperatures of the hotter surface of the i-th honeycomb core
T Ci	temperatures of the cooler surface of the i-th honeycomb core
t	honeycomb wall thickness
λ	thermal conductivity
λ ci	equivalent thermal conductivity of the honeycomb core in i-th layer
λ equ	equivalent thermal conductivity
λ f	thermal conductivity of panel
λ fci	equivalent thermal conductivity of the i-th honeycomb core contributed by radiation
λ gci,	equivalent thermal conductivity of the i-th honeycomb core contributed by air conduction
λ g	thermal conductivity of the air
λ s	thermal conductivity of the honeycomb wall
λ sci,	equivalent thermal conductivity of the i-th honeycomb core contributed by solid conduction
${\Delta }_t$	time interval
α	ratio of the honeycomb core height to its inner tangent circle diameter
δ	Kronecker delta symbol
ε	radiation emissivity
σ	Stefan-Boltzmann coefficient
[E]	radiation reflectance matrix
[F]	view factor
[G]	net radiation coefficient matrix
[ε]	radiation absorptivity matrix