Cube subject to isothermal boundary conditions

A cube with a one-length edge, size 1m, as shown in the next figure is subject to isothermal boundary conditions of 373 ºK on all faces except the top face, which is subject to 773 ºK. The thermal conductivity of the material is constant and equal to 10W/mºK.

The cubic domain is divided in Tetrahedron elements as shown in next figure. The project for this simulation can be found here.

This problem is an extension in three dimension of the problem described in Square Plate subject to isothermal boundary conditions. As it can be seen, the goemetry has been extended in the third dimension by one meter. The boundary conditions are the same, but extended into three dimensions (the boundary sides are faces instead of edges). The extra surfaces (one in the front and the other in the back) are subjected to no heat flux condition (isolated surfaces). This brings about the problem to be two-dimensional despite being a three dimensional problem.

The temperature obtained at the center of the cube (x=0.5, y=0.5, z=0.5) has been 472.723K (199.723ªC).