Air Conditioning and Ventilation Webinar
Air-conditioning simulation of an office space
Import the project by clicking the link below.
Once the project is imported, the workbench is automatically opened. Then follow the steps below for setting up a convective heat transfer simulation.
- In the ‘Mesh Creator’ tab, click on the geometry ‘Office’
- Then, click on ‘Mesh geometry’ button in the options panel.
- Select the mesh type to be Hex-dominant automatic for internal flow (only CFD), select fineness 3 (Moderate), as shown in the image below.
- Layer addition is important to capture the flow phenomenon near the boundaries. Hence layers should be added to all the surfaces except the inlet and outlet. This can be done by selecting all surfaces and then deselecting the inlet and outlet boundaries, as shown in the following 2 images.
- Apply these surfaces by selecting Add selection from viewer option and then click the Save button.
- Select the Start to begin the mesh operation.
- A message that the mesh operation is complete is seen in the left tab when the mesh generation is complete. It takes approximately 15 mins for the mesh operation to complete.
- For setting up the simulation switch to the Simulation Designer tab and select New simulation.
- Change the analysis type to Natural convective heat transfer under Fluid dynamics. Select laminar steady-state type and click Save button.
- The simulation tree now looks as shown below.
- Click ‘Domain’ from the tree and select the mesh created from the previous task. Click the Save button.
- Click ‘Topological Entity Sets’ to name the different boundary conditions - inlet, outlet and walls, by selecting each surface from viewer and clicking Create entity set from selection for the inlet and outlet. For walls - select all the surfaces and remove the inlet and outlet selection.
- Click on ‘Model’ and enter gravity value in negative z-direction.
- Select ‘Material’ from the sub-tree and click Add fluid material.
- Scroll to the bottom of the page and select Import from material library.
- Click Air and select the Save button.
- Select region0 from Topological Mapping and click the Save button.
- Under ‘Initial condition’ from the tree, select velocity and enter a ‘y value’ of -0.1 m/s. Click the Save button.
- Click on ‘Boundary condition’ and select Add boundary condition.
- Enter the inlet boundary condition of y-direction flow at -0.75m/s and 283K. Select the inlet boundary and click Save option.
- Add another boundary for outlet with pressure condition, as shown below.
- Create another boundary condition for the walls at 293K.
- Select ‘Numerics’ from the sub-tree and enter the following values. This enhances us to get the appropriate results.
- Click on ‘Simulation control’ and setup the simulation run for 1000s time with a time step of 1.
- Select ‘Simulation runs’ and click Create new run. Select the run and press Start button.
- Once the simulation is over switch to obtain the results by clicking on Post-process results under Results.
- Click on the solution field (‘Run 1’ in this case) and create a slice by clicking Add filter and selecting Slice.
- Enter the values as shown below. Similarly click on Run 1 and create 2 more slices with the entries shown below.
- The viewer looks as follows after the slices are created.
- It might be interesting to add another instant of the region for better visualization. This can be done by right clicking Solution field and select Add result to viewer.
- Select the new field and enter the following properties to decrease its opacity.
- Select each slice and select the field to U [point data] to display velocity. Also switch to the last instant of time step.
- A stream tracer is created to visualize the flow by adding another filter. Enter the values as shown below.