Selecting the Physics Models and Specifying the Material Properties

You model the steady-state turbulent flow of a gas through the backward facing step using the Realizable K-Epsilon model in conjunction with the high y+ wall treatment.

  1. Select the physics models for the physics continuum:
    1. Expand the Continua node and rename Physics 1 to Fluid.
    2. Select the following models for Fluid, in order:
      Group Box Model
      Space Two-Dimensional (Pre-Selected)
      Time Steady
      Material Gas
      Flow Coupled Flow
      Gradient Metrics Gradients (Selected automatically)
      Equation of State Constant Density
      Viscous Regime Turbulent
      Turbulence Reynolds-Averaged Navier-Stokes (Selected automatically)
    3. Deactivate Auto-select recommended models. The appropriate models are selected manually.
    4. Select the following models, in order:
      Group Box Model
      Reynolds Averaged Turbulence K-Epsilon Turbulence
      K-Epsilon Turbulence Models Realizable K-Epsilon
      Wall Distance Wall Distance (Selected automatically)
      K-Epsilon High y+ Wall Treatment High y+ Wall Treatment
      Optional Models Coupled Energy
    5. Click Close.
  2. Edit the Fluid > Models > Gas > Air > Material Properties node and set the following values:
    Node Property Value
    Density > Constant Value 2 kg/m^3
    Dynamic Viscosity > Constant Value 7.142E-5 Pa-s
    Specific Heat > Constant Value 1000.0 J/kg-K
    Thermal Conductivity > Constant Value 0.1 W/m-K
  3. To modify the turbulence specification, select the Fluid > Initial Conditions > Turbulence Specification node and set Method to Intensity + Length Scale.
  4. Save the simulation.