Home
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.
Boundaries
Define surface boundary conditions.
Define Slip Walls
Use the Slip tool to define wall surfaces which have zero shear stress and through which there is no normal velocity.

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.
    - Setup
      Define global simulation settings, materials, and any multipliers or parameters.
    - Domain
      Define the simulation domain.
    - Boundaries
      Define surface boundary conditions.
      - Boundary Condition Types
        All of the problems in fluid dynamics are governed by the same standard conservation equations. What makes the solution of each problem unique is the set of boundary conditions.
      - Define Default Wall Conditions
        Use the Default Wall tool to edit the default properties of unassigned wall surfaces. If you later assigns properties to a surface, it will be removed from the default domain.
      - Define Profiled Inlets
        Use the Profiled tool to apply boundary conditions on surfaces where the flow enters the domain.
      - Define Inlets with Constant Velocity
        Use the Constant tool to define an opening surface with a constant velocity.
      - Define Pressures
        Use the Pressure tools to enforce pressure on the nodes of a surface.
      - Define Far Field Conditions
        Use the Far Field tool to define surfaces far away from the source of disturbance.
      - Define Atmospheric Inlets
        Use the Atmospheric tool to define atmospheric boundary layers at an inlet.
      - Define Outlets
        Use the Outlet tool define boundary conditions on surfaces where flow is exiting the domain.
      - Define No Slip Walls
        Use the No Slip tool to define physical walls in the simulation domain.
      - Define Baffle Surfaces
        Use the Baffles tool to define baffle surfaces.
      - Define Moving Walls
        Use the Moving tool to define a surface moving at a certain velocity. This condition then imposes that velocity to the fluid.
      - Define Slip Walls
        Use the Slip tool to define wall surfaces which have zero shear stress and through which there is no normal velocity.
      - Define Symmetry Conditions
        Use the Symmetry tool to define a surface as a symmetry plane.
      - Define Periodic Conditions
        Use the Periodic tool to define boundaries with translational, rotational, and streamwise periodicity. With a periodic condition, you can represent a larger periodic model by applying settings to just a section.
      - Define Boundaries Using Groups
        Use the Advanced Create dialog in the Setup Browser to create boundaries conditions for selected entity groups.
  - Radiation
    Define radiation conditions and create emissivity models.
  - Motion
    Define direct, derived, and constrained mesh motion.
  - 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.

View All Altair HyperWorks Help

Define Slip Walls

Use the Slip tool to define wall surfaces which have zero shear stress and through which there is no normal velocity.

Select the surfaces or thin solids on which to apply the boundary condition.

To Select

Do This

Surfaces

Select surfaces in the following ways:

While in the Flow ribbon, select surfaces, then right-click and select Assign Wall > Slip from the context menu.
From the Flow ribbon, click the Slip tool.
Figure 1.

Select surfaces.

Thin Solids

From the Flow ribbon, click the Slip tool.
Figure 2.
Change the guide bar selector to Thin Solids.
Select thin solids.
Note: You can only select thin solids if layers have been defined using the Thin tool.
Select a direction option from the guide bar.
- Direction: Away from Parent Surface - Define the condition on the boundary surface furthest from the parent surface.
- Direction: Adjacent to Parent Surface - Define the condition on the boundary surface closest to the parent surface.
- Direction: Both Sides - Define the condition on both sides of the boundary surface.

In the dialog, enter a value for Precedence.
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.