# Overview
The concentricCylinders case simulates radiative heat transfer between two
concentric cylinders. The '-baffle' option in the 'Allrun' script introduces a
cylindrical baffle between the cylinders.

# Setup
+ The case geometry includes the following diameters: inner cylinder = 0.2m;
outer cylinder = 1.0m; baffle = 0.6m.
+ The temperatures of the inner and outer cylinders are Tin = 400K and Tout =
800K, respectively.
+ The emissivity of the cylinders and baffle is 0.5.

# Theoretical solution
The theoretical solutions for the net rate of radiative heat transfer, qrad,
are as follows.
+ Without baffle: qrad = sigma*(Tout^4 - Tin^4)*pi/11 = 6218W.
+ With baffle: qrad = sigma*(Tout^4 - Tin^4)*pi/16 = 4275W.

# Baffle
The 'thermalBaffle1D' boundary condition is used to model the baffle. The
thickness of the baffle is set to 2mm to approximate a thin (zero thickness)
baffle.