Notes on Ansys Fluent Local Sizing Task

Introduction to Ansys Fluent

• Ansys Fluent is an industry-leading fluid simulation software.
• Known for advanced physics modeling capabilities and accuracy.

Importance of Meshing

• High-quality CFD mesh preparation is crucial for simulations.
• Meshing process can be time-consuming and challenging.
• Ansys Fluent offers a watertight geometry workflow that simplifies the meshing process.
• Guided workflow enhances efficiency and ease of use.

Geometry Import Task

File Import Options

• CAD Import: Starts from CAD geometry.
• Mesh Import: Starts from existing surface/volume mesh files or Ansys Fluent case files.

Clean and Watertight Geometry Requirements

• Clean CAD: Error-free geometries.
• Watertight CAD: No gaps, holes, or leaks.
• Geometry can be a single body or a combination of multiple bodies.
• Multi-body parts should have individually watertight bodies.
• Recommended to perform share topology operation on geometries involving multiple bodies.
• Group surfaces and create labels before importing for better management during simulation.

Importing Geometry

• Geometry units can be set (e.g., mm).
• Click Import to load the CAD into the workflow.
• Use clipping planes to visualize the geometry.

Adding Local Sizing

Definition of Local Sizing

• Local sizing provides instructions on mesh sizing for specific parts or regions of the geometry.
• Important for surface and volume mesh levels to resolve features and flow gradients.

Local Sizing Controls

• These include:
  • Face Sizing: Controls mesh size on selected surfaces.
  • Edge Sizing: Controls mesh size along the edges of the geometry.
  • Body Sizing: Controls mesh size for closed volumes or bodies.

Example of Face Sizing

• Select face sizing control type.
• Specify target mesh size (e.g., 1mm).
• Dynamic preview indicates how the sizing will be applied.
• Growth rate affects how mesh size increases away from the selected entity (default is 1.2, recommended for certain simulations is 1.1 or less).

Adding Edge and Body Sizing

• Edge sizing requires named selections defined for edges.
• Body sizing applies to entire closed volumes.
• Can define multiple local sizings with different settings.

Generating Surface Mesh

• Generate surface mesh after defining local sizings.
• Resulting mesh shows variation based on local sizing controls applied:
  • Different distributions for bodies based on applied controls.

Generating Volume Mesh

• Change geometry type for mixed fluid and solid regions.
• Keep default settings for the volume mesh generation.
• Select Poly Hex Core for fill width option during volume mesh generation.
• Observe differences in mesh clustering due to different sizing controls.

Summary of the Lesson

• Importance of meshing and Ansys Fluent's watertight geometry workflow.
• Geometry requirements for watertight workflow.
• Overview of adding local sizing and its control types (Edge, Face, Body).
• Effects of local sizing on surface and volume meshes.