FEM ConstraintHeatflux

Constraint initial temperature

Constraint temperature

FEM

FEM ConstraintHeatflux
Menu location
Model → Thermal boundary conditions and loads → Heat flux load
Workbenches
FEM
Default shortcut
None
Introduced in version
-
See also
FEM tutorial

Description

Defines a convective heat flux load on a surface at a temperature T with a film coefficient h and with the environment (sink) temperature T₀. The convective heat flux q will satisfy: q = h(T -T₀). Optionally, can also define a regular surface heat flux load.

Usage

1. There are several ways to invoke the command:
   • Press the Heat flux load button.
   • Select the Model → Thermal boundary conditions and loads → Heat flux load option from the menu.
2. In the 3D view select the face(s) the heat flux load should be applied to.
3. Enter the desired heat transfer coefficient and environment temperature.

Option

By default, this feature defines a convective heat flux. By using the option Surface heat flux, one can specify a heat flux value in Watts per surface area (W/m^2).

Notes

• The heat flux load uses the *FILM card in CalculiX. It is explained at http://web.mit.edu/calculix_v2.7/CalculiX/ccx_2.7/doc/ccx/node203.html
• The Surface heat flux option uses the *DFLUX card in CalculiX: http://web.mit.edu/calculix_v2.7/CalculiX/ccx_2.7/doc/ccx/node188.html

Constraint initial temperature

Constraint temperature

FEM

FEM

• FEM Analysis

• Materials: Solid, Fluid, Nonlinear mechanical, Reinforced (concrete); Material editor

• Element geometry: Beam (1D), Beam rotation (1D), Shell (2D), Fluid flow (1D)

---

Constraints

• Electromagnetic: Electrostatic potential, Current density, Magnetization

• Fluid: Initial flow velocity, Initial pressure, Flow velocity

• Geometrical: Plane rotation, Section print, Transform

• Mechanical: Fixed, Displacement, Contact, Tie, Spring, Force, Pressure, Centrif, Self weight

• Thermal: Initial temperature, Heat flux, Temperature, Body heat source

• Overwrite Constants: Constant vacuum permittivity

---

• Mesh: Mesh Netgen, Mesh GMSH, Mesh boundary layer, Mesh region, Mesh group, Nodes set, Mesh to mesh

• Solve: CalculiX Standard, Elmer, Mystran, Z88; Equations: Deformation, Elasticity, Electrostatic, Electricforce, Magnetodynamic, Magnetodynamic 2D, Flow, Flux, Heat; Solver: Solver control, Solver run

• Results: Purge, Show; Postprocessing: Apply changes, Pipeline from result, Warp filter, Scalar clip filter, Function cut filter, Region clip filter, Contours filter, Line clip filter, Stress linearization plot, Data at point clip filter, Filter function plane, Filter function sphere, Filter function cylinder, Filter function box

• Utilities: Clipping plane, Remove clipping planes, Open FEM examples; Mesh clear, Mesh display info

---

• 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

---

• Help: Tutorials, Video tutorials
• Workbenches: Std Base, Arch, Assembly, CAM, Draft, FEM, Inspection, Mesh, OpenSCAD, Part, PartDesign, Points, Reverse Engineering, Robot, Sketcher, Spreadsheet, Start, Surface, TechDraw, Test Framework, Web

---

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

---

• Hubs: User hub, Power users hub, Developer hub