Selecting the Physics Models

Physics models define the physical variables and phenomena in the simulation. This simulation requires two physics continua—one for the gas region and one for the shell region.

To define the physics continua:
  1. Rename the existing continuum, Continua > Physics 1, to Fluid.
  2. Create a new physics continuum named Solid Shells.
  3. Select the Regions > Shells node and set Physics Continuum to Solid Shells.
    The Fluid physics continuum is already assigned to the Fluid and Exhaust Gas regions.
In this simulation, you model the gas as turbulent air entering the inlets at a temperature of 450°C. To specify the models that define the behavior of the gas:
  1. Right-click the Continua > Fluid node and select Select Models....
  2. In the Fluid Model Selection dialog, select the following models in order:
    Group Box Model
    Space Three-Dimensional (already selected)
    Time Steady
    Material Gas
    Flow Segregated Flow
    Enabled Models Gradients (selected automatically)
    Equation of State Ideal Gas
    Energy Segregated Fluid Temperature
    Viscous Regime Turbulent
    Turbulence Reynolds-Averaged Navier-Stokes (selected automatically)
    Reynolds-Averaged Turbulence K-Epsilon Turbulence
    Enabled Models Realizable K-Epsilon Two-Layer (selected automatically)
    Two-Layer All y+ Wall Treatment (selected automatically)
    Wall Distance (selected automatically)
  3. Select the Fluid > Initial Conditions > Static Temperature node and set Value to 25.0 C.
  4. Select the Fluid > Initial Conditions > Velocity node and set Value to [1.0, 0.0, 0.0] m/s.
Specify the physics models that define the solid shells.
  1. Right-click the Continua > Solid Shells node and select Select Models....
  2. In the Solid Shells Model Selection dialog, select the following models in order:
    Group Box Model
    Space Three Dimensional
    Time Steady
    Material Solid
    Optional Models Segregated Solid Energy
    Equation of State Constant Density
  3. Select the Solid Shells > Initial Conditions > Static Temperature node and set Value to 25.0 C.
After defining the physics continua for the simulation, check the interfaces.
  1. To display the interfaces between the attached shell parts:
    1. Open Geometry Scene 1.
    2. Right-click the Interfaces > Shells/Shells Hub node and select Initialize.
    3. Select the Shells/Shells Hub node.
      The interfaces between the attached shell parts are highlighted in the graphics window.

  2. Save the simulation.