One way to check the accuracy of the simulation is to refine the mesh and re-run the simulation. The smaller the element in the mesh, the more accurate the simulation will be. The only drawback is longer computation time. To refine the mesh, insert Body Sizing on the specimen and set the element size to 0.001 m. Also, enter 0.002 m for the element size in the Details of "Mesh." The original mesh has 620 Elements and 4533 Nodes; the new mesh has 1600 Elements and 11204 Nodes.
|Shell Net Radiation at end step time (W)||Specimen Net Radiation at end step time (W)|
The net radiation shows very little change as the number of elements is doubled. No further mesh refinement is needed.
The view factor is calculated for surface-to-surface radiation. Recall from the radiation equation in pre-analysis, this is an important parameter in computing the radiation between surfaces that are in the same enclosure.
It is difficult to analytically calculate the view factor for this model. Hence, we will use a simplified exercise to show the validity of Ansys simulation. Proceed to the next step to compare the analytic and Ansys results.