Setting up the Gas Composition Using Verified Engine Data

You can use verified engine data to set up the composition of the exhaust gas and the gas composition for initialization and boundary conditions manually.

To set up the composition of the exhaust gas:
  1. Right-click the Materials > Exhaust node and select Edit.
  2. In the Exhaust Properties group-box, set the Mass Weighting for the exhaust components as required.
    For more information, see Materials Reference—Exhaust Dialog.
  3. Click Apply, then Close.
To set the initial gas composition for the cylinder and ports:
  1. Right-click the Engine > Cylinder node and select Edit.
  2. Within the Initial Conditions tab, in the Cylinder group box, set the following properties:
    • Air Mass Weighting
    • Exhaust Mass Weighting
    • Fuel Mass Weighting

    For more information, see Engine Reference—Initial Conditions.

  3. Repeat Step 5 using the group boxes Intake Port [n] and Exhaust Port [n], where [n] specifies the number of the respective port.
  4. Click Apply, then Close.
To set the initial gas composition for plenums:
  1. Right-click the Engine > Plenum [n] node and select Edit.
  2. Within the Initial Conditions tab, in the Fixed Plenum group box, set the initial gas composition as described in Step 5. The mass weighting of fuel is automatically set to zero.
To set the gas composition at the flow boundaries:
  1. For an inlet boundary, edit the Engine > [engine part] > Inlet [n] node, where [engine part] can be Cylinder or Plenum [n].
  2. Within the Edit dialog, in the Species Mass Fraction group box, set the following properties:
    • Air Mass Weighting
    • Exhaust Mass Weighting
    • Fuel Mass Weighting (for inlets in two-stroke engines, this value is automatically set to zero)

    For more information, see Engine Part Surface Reference.

  3. Click Apply, then Close.
  4. To set the species mass weightings at the outlets, repeat Step 10 - 12 for the Engine > [engine part] > Outlet [n] nodes, where [engine part] can be Cylinder or Plenum [n].