33.3.5 View Factor and Cluster Parameters Dialog Box

The View Factor and Cluster Parameters dialog box allows you to set parameters related to surface clusters and view factors for the surface-to-surface radiation model. See Section  13.3.3 for information about using this dialog box.

Controls

Cluster   contains the methods and parameters for creating surface clusters.

Options   gives you a choice of forming clusters either manually or automatically.

Manual   allows you to form clusters manually.

Automatic   allows ANSYS FLUENT to form the cluster automatically.

Radiating Zones   allows you to control the participation of s2s radiation. See Section  13.3.3 for more information.

Select...   opens the Select Radiating Boundary Zones dialog box, where you can include or exclude participation of S2S radiation.

Parameters   contains the parameters for creating surface clusters. See Section  13.3.3 for information about setting the parameters.

Manual   (available only when the Manual option is enabled) allows you to manually specify the number of faces per surface cluster for the flow boundary zones.

Faces per Surface Cluster for Flow Boundary Zones   specifies the number of faces in each surface cluster for flow boundary zones. The default is set to 1. See this section in the separate Theory Guide for details about clustering.

Apply to All Walls   applies the value specified in the Faces per Surface Cluster for Flow Boundary Zones field to all wall zones adjacent to fluid zones.

Automatic   (available only when the Automatic option is enabled) allows you to automatically specify the maximum number of faces per surface cluster.

Maximum Faces per Surface Cluster   specifies the maximum number of faces in each surface cluster. The default is set to 10.

Compute   results in ANSYS FLUENT automatically calculating and updating the face per surface cluster values in the boundary conditions dialog box without computing the clusters.

View Factor   contains parameters for computing the view factors.

Method   specifies the method for computing the view factors. See Section  13.3.3 for information about choosing a method.

Adaptive   specifies the use of the adaptive method for computing the view factors.

Hemicube   specifies the use of the hemicube method for computing the view factors. The hemicube method is available only for 3D and axisymmetric cases.

Ray Tracing   specifies the use of the ray tracing method for computing the view factors. The ray tracing method should not be used when any of the zones are defined as symmetric or periodic.

Surfaces   specifies the geometric orientation of surface pairs with respect to each other when using either the adaptive or hemicube method.

Blocking   specifies that there is another surface blocking the views between the surfaces under consideration.

Nonblocking   specifies that there is no obstruction between the surfaces under consideration.

Parameters   contains parameters related to the hemicube and ray tracing methods for computing the view factors. All of these inputs are available when Hemicube is selected under Method, whereas only Resolution is available when Ray Tracing is selected. See Section  13.3.3 for information about setting hemicube parameters.

Resolution   specifies the resolution of the hemicube. The default value is set to 10. You can increase the value to reduce aliasing effects that can lead to overestimated or underestimated view factors.

Subdivisions   specifies the number of subfaces into which each face is divided. The default value is set to 10. This parameter is only available for the hemicube method.

Normalized Separation Distance   specifies the ratio of the minimum face separation to the effective diameter of the face. The default value is set to 5. This parameter is only available for the hemicube method.

Smoothing   specifies whether or not smoothing should be performed on the view factor matrix when using the adaptive or hemicube method. See this section in the separate Theory Guide for details about smoothing.

None   specifies that the view factor matrix will not be smoothed.

Least Squares   specifies that the least-squares method will be used for smoothing the view factor matrix.