Set Up the Simulation Model

Use the Physics tool to define the global AcuSolve settings used in the simulation.

Based on the selected model, required attributes in domains and boundaries will change.

  1. Open the Physics tool in the following ways:
    • From the Flow ribbon, click the Physics tool.


      Figure 1.
    • Right-click in empty space in the Setup Browser and select Global Settings.
    The Setup dialog opens.
  2. Define the physics models and their parameters.
    • Time
    • Flow
    • Heat transfer
    • Multifluid
    • Species transport
  3. Click Solver controls and define the solver settings.

Set Up Immiscible Multiphase Modeling

  1. From the Flow ribbon, click the Physics tool.


    Figure 2.
  2. Click Multifluid under Settings.
  3. Change the Multifluid type to Immiscible.
  4. Select a field interaction material model from the drop-down menu or click Material Library to create, edit, and manage custom material models.
After setting up the immiscible multiphase physics, you have the option to choose the incoming fluid when defining inlet boundary conditions.


Figure 3.
In addition, you can select the fluid as a variable when defining initial conditions in the Solution ribbon.


Figure 4.

Set Up Disperse Multiphase Modeling

Disperse multiphase modeling gives you the capability to simulate the momentum exchange between a carrier field and a dispersed field. When simulating multiphase flows using the disperse multiphase model, the carrier field has to be a fluid and the dispersed field can be of any medium.

  1. From the Flow ribbon, click the Physics tool.


    Figure 5.
  2. Click Multifluid under Settings.
  3. Change the Multifluid type to Disperse.
  4. Select a disperse material model from the drop-down menu or click Material Library to create, edit, and manage custom material models.
After setting up the disperse multiphase physics, you have the option to set the carrier fluid volume fraction in all inlet and outlet (backflow condition) boundaries.


Figure 6.
In addition, you can select the carrier volume fraction as a variable when defining initial conditions in the Solution ribbon.


Figure 7.

Set Up Humidity Modeling

  1. From the Flow ribbon, click the Physics tool.


    Figure 8.
  2. Click Heat Transfer under Settings.
  3. Activate the Heat transfer option.
  4. Click Multifluid under Settings.
  5. Change the Multifluid type to Humidity transport.
After setting up the humidity physics, you have the option to define the humidity input when creating inlet boundary conditions.


Figure 9.
In addition, you can select humidity properties as variables when defining initial conditions in the Solution ribbon.


Figure 10.

Set Up Species Transport Modeling

Species transport modeling gives you the capability to simulate and track multiple species in a fluid flow by using the scalar transport equations for each of them individually.
  1. From the Flow ribbon, click the Physics tool.


    Figure 11.
  2. Click Species transport under Settings.
  3. Activate the Species option and enter a number.
    You can define up to nine species.
Once species transport is turned on in the Physics Setup dialog:
  • The diffusivity of each species can be defined in material library.


    Figure 12.
  • All material properties can be set as a functions of species concentration. This models a ‘miscible’ property relative to mixing of multiple fluids.


    Figure 13.
  • You can define the concentration of each species at all inlet boundaries using the species tab.


    Figure 14.
  • You can define species concentration or fluxes on wall boundary conditions.
  • In addition, you can specify species source per unit volume or per unit mass for a species transport equation. The definition can be constant or varying.
  • You can define the initial concentrations of species.