Specify Heat Exchangers

Identify the inflow, outflow, inertial resistance, and viscous resistance of heat exchangers, which are modeled as a porous medium.

Heat exchanger parts are often located in the engine compartment and hidden by other parts, therefore it is advisable to isolate the relevant parts.
All other input parameters, like permeability direction, or the frame of the heat exchanger are defined automatically but can be modified via the property sheet of each individual heat exchanger.
Identify the heat exchangers in one of the following ways: as a series of in/out surfaces or as a single solid. Setting up a single solid heat exchanger is more straightforward but requires you to define the permeability direction.
  • Use the Identify Heat Exchanger tool. You can choose to define each part of the heat exchanger solid, or define the solid as a whole. To define the heat exchanger using in/out surfaces:
    1. From the Setup ribbon, click the Identify Parts tool.
      Figure 1.


    2. From the secondary tool set, click the Heat Exchanger tool.
      Figure 2.


    3. In the Heat Exchangers dialog, select the desired heat exchanger.
    4. Specify the inflow component.
      1. From the Identify Heat Exchanger tool, click the In arrow.
      2. Select the corresponding component.
      Figure 3.


    5. Specify the outflow component.
      1. From the Identify Heat Exchanger tool, click the Out arrow.
      2. Select the corresponding component.
      Figure 4.


      In general the heat-exchanger is modeled as a rectangular volume. As soon as the inlet and outlet of the heat exchanger are defined, VWT automatically identifies the connecting wall between those two surface regions.

    6. Optional: Manually define the connecting wall.
      1. From the Identify Heat Exchanger tool, click the Wall icon.
      2. Select the corresponding component.
      Figure 5.


    7. Optional: If using thermal functionality, choose the desired Thermal Mode and then define the required properties in the Property Editor.
      Note: Activate thermal functionality by enabling Thermal Model in the Run dialog.
    • Constant heat
      Applies a constant heat through the heat exchanger, defined in W.
    • Fluid temperature
      Simulates a fluid moving through the heat exchanger, defined in K.
    • Coolant temperature
      Simulates a coolant moving through the heat exchanger. This thermal mode requires more properties to be defined, as well as selecting a reference surface.
      Figure 6.
      Figure 7.
  • Right-click on a part in the modeling window or the Model Browser and select Identify As > Heat Exchanger Inlet/Outlet/Wall from the context menu.
  • Select a part in the modeling window or the Model Browser then change the Identify As field to Heat Exchanger Inlet/Outlet/Wall in the Property Editor.

  • To define the heat exchanger as a whole solid:
    1. Click the icon in the Heat Exchangers dialog.
    2. From the Identify Heat Exchanger tool, click the Wall icon.
    3. Highlight the entire solid.
    4. Define the permeability direction in the Property Editor when creating a single solid heat exchanger.
      Figure 8.
Identified parts are marked in the Model Browser by corresponding icons for the heat exchanger wall, inflow, and outflow.
Tip:
  • Open the Property Editor and review the parameters associated with a particular heat exchanger by left-clicking on parts identified as a heat exchanger in the Model Browser. Heat exchanger properties that can be set include: inertial and viscous resistance, permeability direction, and thermal properties.
  • Define additional heat exchangers by clicking in the Heat Exchangers dialog. This will increase an internal index to number all heat exchangers.
  • Use the right-click context menu in the Heat Exchangers dialog to delete and rename heat exchangers.