Setting Up Post-Processing

Before running the simulation, you prepare scenes and plots to display the temperature and soot mass density across a cross section of the fluid domain, and a 3-D flame using volume rendering.

  1. Create a scalar scene to view the temperature on a cross-section of the fluid domain which intersects the inlet boundary.
    1. Create a scalar scene and rename it Temperature.
    2. Expand the Temperature > Scalar 1 node and set the following properties:
      Node Property Value
      Scalar 1 Contour Style Smooth Blended
      Parts Parts Derived Parts > Plane Section
      Scalar Field Function Temperature
  2. Create a scene to visualize the 3D flame using volume rendering.
    1. Create a scalar scene and rename it 3D Flame.
    2. Right-click the 3D Flame node and select New Displayer > Surface.
    3. Expand the Surface 1 node and set the following properties:
      Node Property Setting
      Surface 1 Color Mode Constant
      Representation Geometry
      Parts Parts
      • Parts > Exterior
      • Parts > Interior
      • Parts > Liner
    4. With the 3D Flame scene active in the Graphics window, right-click the Derived Parts node and select New Part > Resampled Volume.
    5. To confirm the default volume selection and settings, click Create then Close.
    6. Expand the 3D Flame > Scalar 1 node and set the following properties:
      Node Property Setting
      Scalar 1 Opacity 0.1
      Parts Parts Derived Parts > Resampled Volume
      Scalar Field Function Temperature
      Color Bar Color Map gray-darkred
      Reverse activated
      Resampled Volume Settings Lighting Mode Local Lighting
      Quality 1.0
  3. Create a scalar scene to view the soot mass density on a cross-section of the fluid domain which intersects the inlet boundary.
    1. Right-click the Scenes > Temperature node and select Copy, then right-click the Scenes node and select Paste.
    2. Rename the copy, Soot.
    3. Expand the Soot > Scalar 1 node and set the following properties:
      Node Property Setting
      Scalar Field Function Soot Mass Density
      Color Bar Title Height 0.05
      Label Height 0.04
      Orientation Vertical
    4. Copy the Scenes > 3D Flame > Surface 1 node and paste it onto the Soot node.
You can use the many reports, monitors, and plots that are available to display the output from the simulation and assess how well the simulation is converging. For example, comparing the mass flow at the inlet with the mass flow at the outlet shows if the overall mass balance is equal—the overall mass balance equalizes as the simulation converges. The mass flow averaged reports also stabilise as the simulation reaches convergence. In industry, it is important to monitor NOx and soot emissions from combustors. This tutorial provides custom field functions which you use to calculate the NOx emissions (dry emissions corrected at 15% O2 reference, [986]).
  1. Right-click the Reports node and select New > Flow / Energy > Mass Flow Averaged. Then repeat the process to create two more mass flow averaged reports, two mass flow reports, and one New > User > Expression report.
  2. Rename the reports as follows:
    Mass Flow Averaged 1 Mass Flow Averaged Temperature
    Mass Flow Averaged 2 Mass Flow Averaged NOx (ppmv)
    Mass Flow Averaged 3 Mass Flow Averaged Soot Mass Density
    Mass Flow 1 Mass Flow Inlet
    Mass Flow 2 Mass Flow Outlet
    Expression 1 Mass Flow Imbalance
  3. Edit the Reports node and set the following properties:
    Node Property Setting
    Mass Flow Averaged Temperature Field Function Temperature
    Parts Regions > Fluid Volume > Outlet
    Mass Flow Averaged NOx (ppmv) Field Function NOx (ppmv)
    Parts Regions > Fluid Volume > Outlet
    Mass Flow Averaged Soot Mass Density Field Function Soot > Soot Mass Density
    Parts Regions > Fluid Volume > Outlet
    Mass Flow Inlet Parts Regions > Fluid Volume > Inlet
    Mass Flow Outlet Parts Regions > Fluid Volume > Outlet
    Mass Flow Imbalance Definition abs(${MassFlowOutletReport})-abs(${MassFlowInletReport})
  4. To create monitors and plots from the reports:
    1. Multi-select the following report nodes:
      • Mass Flow Averaged Temperature
      • Mass Flow Averaged NOx (ppmv)
      • Mass Flow Averaged Soot Mass Density
    2. Right-click one of the selected nodes and select Create Monitor and Plot from Report.
    3. In the Create Plot From Reports dialog, click Multiple Plots (one per report).
    4. Right-click the Reports > Mass Flow Imbalance node and select Create Monitor and Plot from Report
  5. Save the simulation.