FEM: Strato limite di mesh FEM

Mesh FEM da forma con GMSH

Regione di mesh FEM

FEM

FEM MeshBoundaryLayer
Posizione nel menu
Mesh → FEM Mesh boundary layer
Ambiente
FEM
Avvio veloce
Nessuno
Introdotto nella versione
-
Vedere anche
Tutorial FEM

Descrizione

The FEM MeshBoundaryLayer command enables the user to set a localized set of meshing parameters by selecting an edge and applying the parameters to it.

It is especially useful for refining meshes close to edges or surfaces in flow simulations. For example, it can be used to refine the mesh in the vicinity of an air foil or obstacle in a flow.

The boundary layer has the advantage of creating highly defined, anisotropic meshes. As the name implies it supports accurate calculations near boundaries, e.g. a wall where friction occurs, generating a velocity gradient.

Utilizzo

1. To enable the command a 2D Mesh From Shape by Gmsh must be provided first.
2. Select the Mesh object in the Tree View.
3. There are several ways to invoke the command:
   • Press the 2D Boundary Layer button.
   • Select the Mesh → GMSH Refinements → 2D Boundary Layer option from the menu.
4. Edit the maximum number of layers, minimum/1st thickness and growth ratio.
5. Press the Add button. Select an edge. introduced in 1.1: To remove objects from the selection, press the Remove button.
6. Click the OK button.
7. Close the task.

   Result: You should now see a new MeshBoundaryLayer object under the FEMMeshGMSH object in your active analysis container.

8. Double-click on the FEMMeshGMSH parent object in your Model Tree and press Apply to force a mesh recalculation.
9. Close the task.

After the mesh has been created, you can change its properties using the Property View. After you change a property, you must reopen the Gmsh dialog again and click the Apply button. (You can leave the dialog open while changing properties.)

You can create as many different mesh boundary layers as needed.

Example of a 2D boundary layer around a hole

Mesh FEM da forma con GMSH

Regione di mesh FEM

FEM

FEM

• New Analysis

• Materials: Solid Material, Fluid Material, Non-Linear Mechanical Material, Reinforced Material (Concrete); Material Editor

• Element Geometry: Beam Cross Section, Beam Rotation, Shell Plate Thickness, Fluid Section for 1D Flow

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• Electromagnetic Boundary Conditions: Electrostatic Potential Boundary Condition, Current Density Boundary Condition, Magnetization Boundary Condition, Electric Charge Density

• Fluid Boundary Conditions: Initial Flow Velocity Condition, Initial Pressure Condition, Flow Velocity Boundary Condition

• Geometrical Analysis Features: Plane Multi-Point Constraint, Section Print Feature, Local Coordinate System

• Mechanical Boundary Conditions and Loads: Fixed Boundary Condition, Rigid Body Constraint, Displacement Boundary Condition, Contact Constraint, Tie Constraint, Spring Boundary Condition, Force Load, Pressure Load, Centrifugal Load, Gravity Load

• Thermal Boundary Conditions and Loads: Initial Temperature, Heat Flux Load, Temperature Boundary Condition, Body Heat Source

• Overwrite Constants: Constant Vacuum Permittivity

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• Mesh: Mesh From Shape by Netgen, Mesh From Shape by Gmsh, Mesh Boundary Layer, Mesh Refinement, Mesh Group, Erase Elements, FEM Mesh to Mesh

• Solve: Solver CalculiX, Solver Elmer, Solver Mystran, Solver Z88; Mechanical Equations: Elasticity Equation, Deformation Equation; Electromagnetic Equations: Electrostatic Equation, Electricforce Equation, Magnetodynamic Equation, Magnetodynamic 2D Equation, Static Current Equation; Flow Equation, Flux Equation, Heat Equation, Solver Job Control, Run Solver

• Results: Purge Results, Show Result, Apply Changes to Pipeline, Post Pipeline From Result, Pipeline Branch, Warp Filter, Scalar Clip Filter, Function Cut Filter, Region Clip Filter, Contours Filter, Glyph Filter, Line Clip Filter, Stress Linearization Plot, Data at Point Clip Filter, Calculator Filter; Filter Functions: Plane, Sphere, Cylinder, Box; Data Visualizations: Create Lineplot, Create Histogram, Create Table

• Utilities: Clipping Plane on Face, Remove All Clipping Planes, FEM Examples; Clear FEM Mesh, Display Mesh Info

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• Additional: Preferences; FEM Install, FEM Mesh, FEM Solver, FEM CalculiX, FEM Concrete; FEM Element Types

User documentation

• Getting started
• Installation: Download, Windows, Linux, Mac, Additional components, Docker, AppImage, Ubuntu Snap
• Basics: About FreeCAD, Interface, Mouse navigation, Selection methods, Object name, Preferences, Workbenches, Document structure, Properties, Help FreeCAD, Donate

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• Addons: Addon Manager, External workbenches, Scripting and macros

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