# Example

This example focuses on the impact of Global Mesh Attributes on the resulting mesh.

The geometry under consideration is the pipe example. There are three surface groups (inflow, wall and outflow) and one volume group (fluid). Mesh attributes for surface and volume groups are inactive in this example. The Global Mesh Attributes panel provides the mesh controls at the model level. The default settings for the Relative mesh size and Curvature refinement parameters are retained.

The mesh generator is then launched from the menu bar by clicking Tools > Generate Mesh. Again, the default mesh generation process parameters are used.

The inflow surface has about 32 edges on the circular boundary. The maximum edge dimension of the bounding box of the pipe is 0.05m and the diameter of the pipe is 0.05m. Relative mesh size is 0.1, so the mesh size is internally computed to be 0.005m. The circumference of the circle divided by the mesh size yields approximately 32 edges (π * 0.05 / 0.005 = 31.4) on the circular boundary. Using the Curvature angle of 25 degrees, the mesh edge length is determined to be 0.01m. Hence, Relative mesh size takes precedence over curvature meshing parameters because AcuMeshSim always selects the smallest defined mesh size for each feature.

The Curvature angle from the previous example is now reduced to five degrees and the mesh generator is launched again. This produces a mesh with approximately 37 edges along the circumference of the inflow boundary. This corresponds to a mesh size of 0.0042m. In this example, the Curvature angle of five degrees results in an edge length of approximately 0.002m. However, the minimum value of the mesh edge length (h) was constrained to be approximately 0.004m by setting the Curvature mesh size factor to 0.9, which resulted in 37 edges. Reducing the Curvature mesh size factor to a number smaller than 0.4 would give you a mesh size close to 0.002m. It is very important to note that the curvature meshing is the only place where the minimum mesh size is constrained in this manner. In all other cases, AcuConsole uses the smallest of all the mesh sizes that are inherited by the associated geometric entity.