Apply Boundary Conditions

Apply boundary conditions, such as flow conditions and wall temperatures, to the fluid domain.

Applying boundary conditions to a fluid domain defines how the fluid flows through or around the model. Common types of boundary conditions include hydrostatic pressure, free streams, intake or exhaust fans, inlet velocities, and outlet pressures.

In this example, you apply mass flow conditions at the inlet nozzle to prescribe the mass flow and temperature of the water entering the heat exchanger. Next, you apply pressure conditions at the outlet nozzle to prescribe the speed of the water exiting the heat exchanger. Finally, you define temperature conditions for the tube surfaces that contact the water.

  1. Specify the magnitude and the temperature of the mass flow entering the inlet nozzle.
    1. From the Boundaries section of the Assistant, click Mass Flow Inlet .
    2. Select the blue circular glyph at the inlet nozzle as the support.
      A set of arrows appears in the 3D area. These arrows represent the direction of the mass flow.
    3. Enter 0.84kg_s as the Mass flow rate.
    4. Enter 301.15Kdeg as the Temperature.
    5. Click OK.
  2. Specify the pressure of the flow at the outlet nozzle.
    1. From the Boundaries section of the Assistant, click Pressure Outlet .
    2. Select the blue circular glyph at the outlet nozzle as the support.
      A set of arrows appears in the 3D area.
    3. Enter 0N_m2 as the Static gauge pressure.
    4. Click OK.
  3. Specify the temperature at the outer walls of the tube bundle.
    1. From the Boundaries section of the Assistant, click Wall .
    2. Select the surface definition that you created previously (Tube Bundle).

      Tip: Locate the surface definition in the tree under Model > Heat Exchanger A.1 > Coolant Mesh A.1 > Abstractions > Physical Environment.1 > Local Selections.1.



    3. From the Thermal condition options, select Temperature.
    4. Enter 338.15Kdeg as the Temperature.
    5. Click OK.