A	area [m2]
C	concentration ratio [-]
d	diameter [m]
f	focal distance [m]
G	beam solar irradiance [W/m2]
Gr	Grashof number [-]
h	convective heat transfer coefficient [W/(m2 K)]
k	thermal conductivity [W/(m K)]
L	length [m]
Nu	Nusselt number [-]
Q	distance between the surface of the concentrator and the focal point [m]
$\dot{\mathrm{Q}}$	heat transfer rate [W]
T	temperature [K]
v	wind speed [m/s]
Greek symbols
α	absorptivity [-]
δ	thickness [m]
ε	emissivity [-]
η	efficiency [-]
θ	incident angle [deg]
σ	Stefan–Boltzmann constant [W/(m2 K4]
ψrim	rim angle [deg]
Subscripts
amb	ambient
ap	aperture
cav	receiver cavity
conc	concentrator
d	dish
eff	effective
insul	insulation
rec	receiver