Mesh for N=4 Fixed Bed of Spheres

The full-bed simulation geometry and some details of the graded mesh on the sphere surfaces can be seen in the figure. In particular, the mesh refinement near the contact points is clearly seen. Only fluid flow has been solved to date using the graded mesh on the fluid region. To accommodate heat transfer, a coarser mesh for both fluid and solid regions was created. The full bed flow results from the coarser mesh could be compared to those from the finer, graded mesh. The figure also shows the periodic nature of the model geometry. In a periodic boundary model the inlet and outlet plane geometries are identical and the flow conditions are set to be identical as well. This effectively imposes the outlet conditions of the bed section on the inlet, and therewith establishes the translational periodic condition and creates a model of a generic section in the bed.