Flow Simulation considers the real model created in SOLIDWORKS and automatically generates a rectangular computational mesh in the Computational Domain distinguishing the fluid and solid domains.
The corresponding Computational Domain is generated in the form of a rectangular parallelepiped enclosing the model for both the 3D analysis and 2D analysis. Its boundaries are parallel to the Global Coordinate System planes. For External flows, the computational domain’s boundary planes are automatically distanced from the model. For Internal flows, the computational domain’s boundary planes automatically envelop either the entire model, if Conduction is considered, or if Conduction is not considered, the model’s flow passage only.
In the mesh generation process, the computational domain is divided into uniform rectangular parallelepiped-shaped cells, which form a so-called Basic Mesh. Then, using information about the model geometry, the specified boundary conditions and goals Flow Simulation further constructs the mesh by means of various refinements, i.e. splitting of the Basic Mesh cells into smaller cells, thus better representing the model and fluid regions. The mesh, which the calculation starts from, so-called Initial Mesh, is fully defined by the generated basic mesh and the refinement settings.
Each refinement has its criterion and level. The refinement criterion denotes which cells have to be split, and the refinement level denotes the smallest size, which the cells can be split to. Regardless of the refinement considered, the smallest cell size is always defined with respect to the basic mesh cell size so the constructed Basic Mesh is of great importance for the resulting computational mesh.
The main types of refinements are:
Cell Type Refinement;
Channel Refinement;
Advanced Refinements:
Small Solid Features Refinement,
Curvature Refinement,
Tolerance Refinement.
In addition, the following type of refinements can be invoked locally:
Equidistant Refinement;
During the calculation, the Initial Mesh can be refined further using the Solution-Adaptive Refinement (see “Refinement of the Computational Mesh During Calculation”).
Though it depends on a refinement which criterion or level is available for user control, we will consider all of them (except for the Solution-Adaptive Refinement) to give you a comprehensive understanding of how the Flow Simulation meshing works.