FEM ConstraintFlowVelocity/ru: Difference between revisions
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==Применение== |
==Применение== |
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# Press the {{Button|[[Image:FEM_ConstraintFlowVelocity.svg|16px]] |
# Press the {{Button|[[Image:FEM_ConstraintFlowVelocity.svg|16px]] [[FEM_ConstraintFlowVelocity|Flow velocity boundary condition]]}} button or select the menu {{MenuCommand|Model → Fluid boundary conditions → [[Image:FEM_ConstraintFlowVelocity.svg|16px]] Flow velocity boundary condition}}. |
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# Select the target Edges or Faces. |
# Select the target Edges or Faces. |
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# Press the {{Button|Add}} button. |
# Press the {{Button|Add}} button. |
Latest revision as of 15:49, 11 November 2023
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Системное название |
---|
FEM ConstraintFlowVelocity |
Расположение в меню |
Model → Fluid constraints → Constraint flow velocity |
Верстаки |
FEM |
Быстрые клавиши |
Нет |
Представлено в версии |
- |
См. также |
FEM tutorial |
Описание
Устанавливает скорость потока в качестве граничного условия к ребру в 2D или к грани в 3D.
Применение
- Press the
Flow velocity boundary condition button or select the menu Model → Fluid boundary conditions →
Flow velocity boundary condition.
- Select the target Edges or Faces.
- Press the Add button.
- Uncheck Unspecified to activate the necessary fields for edition.
- Set the velocity values or (introduced in version 0.21) specify a formula.
Formulas
It is possible to define a velocity by specifying the velocity profile as formula. In this case the solver sets the velocities at the different positions according to the profile.
To specify for example the velocity profile
for (assuming that e.g. a pipe has the wall at y = 1 m and y = 2 m)
enter this to the Formula field:
Variable Coordinate 2; Real MATC "6*(tx-1)*(2-tx)"
This code has the following syntax:
- the prefix Variable specifies that the velocity is not a constant but a variable
- the variable to calculate the velocity is Coordinate 2, meaning y
- the velocity values are returned as Real (floating point value)
- MATC is the prefix for the Elmer solver that the following code is a formula
- tx is always the name of the variable in MATC formulas, no matter that tx in our case is actually y
That y will only be in the range is set because MATC only evaluates the tx range where the result is positive. This behavior is a bit special but has the advantage that one does not need to specify the range manually.
It is also possible to use more than one variable. See as example the definition of rotations in the displacement constraint.
Примечания
- Компоненты вектора, отмеченные как не указана, будут интерполированы выбранным решателем.
- Любой вектор, который должен быть результатом решателя, должен быть помечен как не указана.
- Если целевая грань или ребро не выровнены с основной декартовой системой координат, можно поставить галочку нормаль к границе.
- Если установлен флажок нормаль к границе, вектор нормали к выбранному ребру или грани равен X, и он будет ориентирован от области сетки.
- Например, если в домен должен поступать поток воздуха со скоростью 20 мм/с, то после отметки нормаль к границе пользователь должен будет ввести -20 мм/с в поле скорость X.
- For a wall with non-slip condition, set all velocity components to 0.
- For a symmetry condition, set the the flow to (0, Unspecified, Unspecified) if Normal to boundary is checked.
- 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
- 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
- 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
- Additional: Preferences; FEM Install, FEM Mesh, FEM Solver, FEM CalculiX, FEM Concrete; FEM Element Types
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