Home
Setup
Prepare your model and run the simulation.
General Setup
Prepare your model for a general AcuSolve simulation.
Motion
Define direct, derived, and constrained mesh motion.
Constraints
Define how the nodes will move around certain surfaces.
Define Surfaces Without Constraints
Use the No Constraints tool to allow the solver to move surfaces according to surrounding node motion.

Welcome
What's New
View new features for HyperMesh CFD 2024.1.
Get Started
Learn the basics and discover the workspace.
Onboarding Resources
Discover HyperMesh CFD functionality with interactive tutorials and community resources.
Solution Layers
Solution-centric workflows allow you to traverse through modeling environments using a dedicated UI layer.
Manage Files and Data
Create, open, import, and save models.
Convert
Use the Convert tool to convert entire models between data types.
Geometry Modeling
Manage CAD, FE, and 2D parametric sketch geometry.
Meshing
Generate surface/volume mesh by defining mesh controls, or interactively create and edit 2D surface mesh.
Setup
Prepare your model and run the simulation.
- General Setup
  Prepare your model for a general AcuSolve simulation.
  - Flow
    Set up the simulation model, materials, domains, and boundaries.
  - Radiation
    Define radiation conditions and create emissivity models.
  - Motion
    Define direct, derived, and constrained mesh motion.
    - Set Up Mesh Motion
      Use the Settings tool to define the mesh motion equation to be solved.
    - Direct Motion
      Define explicit motion or motion sources on solids or surfaces.
    - Derived Motion
      Define how to interpolate the effect of the motion created with the Direct tools.
    - Constraints
      Define how the nodes will move around certain surfaces.
      - Define Planar Slip Surfaces
        Use the Planar Slip tool to constrain surface mesh on planar faces. Mesh on selected surfaces will only be allowed to slip tangentially along the planar surface.
      - Define Guided Surfaces
        Use the Guided tool to constrain/guide nodes along a given surface.
      - Define Free Surfaces
        Use the Free Surface tool to specify free surfaces and impose the appropriate nodal boundary condition on the mesh motion on those surfaces. Free surface properties are defined by surface tension and contact angle parameters.
      - Define Surfaces Without Constraints
        Use the No Constraints tool to allow the solver to move surfaces according to surrounding node motion.
      - Define Interface Surfaces
        Use the Interface Surface tool to define an interface for moving mesh. Optionally, this tool allows you to define topological baffle surfaces as an interface surface.
  - Solution
    Define output conditions, run the simulation, and view the results.
  - AcuTrace
    AcuTrace is particle tracer that runs as a post-processor to AcuSolve.
- Aerodynamic and Aeroacoustic Setup
  Prepare your model for wind tunnel analysis using ultraFluidX.
Post-Processing
Post-process the simulation results by creating visualizations and measurements.
Automation
Automate simulation processes with templates and utility scripts.
Design Exploration
Once the baseline model is prepared, you can define morph volumes, morph geometry, create design shapes and run DOE studies. These tool work for both AcuSolve and ultraFluidX-based workflows.
Solver Help
More resources for AcuSolve and ultraFluidX solvers.

Define Surfaces Without Constraints

Use the No Constraints tool to allow the solver to move surfaces according to surrounding node motion.

This is useful for cases such as piston head motion.

From the Motion ribbon, click the No Constraints tool.

Figure 1.
Select surfaces which should not be constrained.
Selected surfaces are removed from any other motion definitions.
From the guide bar, execute the command in the following ways:
- Click to confirm your selection and remain in the tool.
  This allows you to continue creating instances and helps you visualize and edit instances with the legend.
- Click to confirm your selection and exit the tool.