Mesh Refinements in SimScale

 Mesh refinements are a crucial tool in SimScale for controlling the density of your mesh in specific areas. This allows you to focus computational resources on critical regions where accurate capture of the physics is essential. Here's a breakdown of the key refinement parameters and when to use them:

• Refinements: This refers to the overall concept of applying a finer mesh in designated areas within your domain. SimScale offers various refinement options, including:

  • Box Refinement: Creates a box-shaped region with a finer mesh inside.
  • Cylindrical Refinement: Defines a cylindrical region for mesh refinement.
  • Sphere Refinement: Creates a spherical region with a finer mesh.
  • Surface Refinement: Refines the mesh on a specific surface of your geometry.

• Layer Gradiation Control: This setting determines how the element size transitions from the coarse mesh outside the refinement region to the finer mesh within. Common options include:

  • Linear: Element size changes uniformly between the coarse and fine regions.
  • Exponential: Element size decreases rapidly near the boundary of the refinement region.

• Number of Layers: (Applicable for certain refinement types) This specifies the number of element layers within the refined region. More layers provide a smoother transition and higher resolution near the boundary.

• Overall Relative Thickness: (Applicable for certain refinement types) This defines the total thickness of the refined region relative to the characteristic length scale of the geometry. It helps control the extent of the finer mesh zone.

• Growth Rate: This parameter controls how the element size gradually changes within the refinement region itself. A smooth growth rate helps maintain good mesh quality and avoid abrupt transitions between element sizes.

When to Use Refinement Parameters:

• Use refinements whenever a specific area of your geometry requires a finer mesh for accurate capture of phenomena like:

  • Boundary layers near walls (critical for fluid flow simulations).
  • Regions with high gradients in variables like pressure, velocity, or temperature.
  • Areas with small geometric details that might be poorly captured by the global mesh size.

• Layer Gradiation Control:

  • Use linear gradation for a smooth transition, especially when the physics doesn't involve strong gradients near the refinement boundary.
  • Use exponential gradation for capturing sharp gradients or boundary layers effectively.

• Number of Layers: Use more layers for a smoother transition and higher resolution near the boundary, especially when capturing phenomena with strong gradients.

• Overall Relative Thickness: Adjust this based on the size of the feature you want to capture with the refined mesh. A larger thickness refines a wider region around the feature.

• Growth Rate: Maintain a smooth growth rate within the refinement region to avoid abrupt changes in element size and ensure good mesh quality.

General Tips:

• Start with a coarse mesh and gradually add refinements as needed.
• Use a combination of refinement types and parameters to achieve the desired level of detail in different areas.
• Be mindful of the trade-off between mesh resolution and computational cost.
• Consult SimScale's documentation or support for specific recommendations based on your simulation setup and the physics you're trying to capture.

SimScale Mesh Refinement Refinement Types Box Refinement Cylindrical Refinement Sphere Refinement Surface Refinement Layer Gradiation Control Linear Exponential Number Of Layers Overall Relative Thickness Growth Rate Boundary Layers Gradients Small  Features Physics  Phenomena Smooth Transition High Resolution Computational Cost SimScale Documentation Support