– Energy Equation: On – Viscous model: ‘k-epsilon’, ‘Realizable’
Workshop Supplement
Activating the Energy equation simply says that temperature changes should be simulated in the model.
Workshop Supplement
The mesh check ensures that each cell is in a correct format, connected to other cells as expected. It is recommended to check every mesh immediately after reading it. Failure of any check indicates a badly-formed or corrupted mesh, which will need repairs.
• drag left-mouse-button rotates • drag middle-mouse-button zooms (to zoom in, drag down and right) (to zoom out, drag up and left) • click middle-mouse-button centre on click
Workshop 1 Fluid Flow and Heat Transfer in a Mixing Tee
Introductory FLUENT Training
ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved.
WS1-1
Workshop Supplement
• Mixing of cold and hot water in a T-piece
– how well do the fluids mix? – what are the pressure drops?
It’s a good idea to identify the key simulation outcomes from the start. You can use these to monitor progress of solution.
• If starting from a ready-made mesh file (*.meshdat), start Workbench and import the file (see screenshot below)
– and save the project
• Alternatively, start in the Workbench project that generated the mesh
ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved.
WS1-9
April 28, 2009 Inventory #002601
WS1: Mixing Tee
Define a new material
• In Materials, click ‘Create/Edit...’
– press ‘FLUENT Database...’ – select ‘water-liquid’, press ‘Copy’, then close both windows
Workshop Supplement
ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved.
ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved.
WS1-7
April 28, 2009 Inventory #002601
WS1: Mixing Tee
Change units of temperature
• Click ‘Units’
• Press ‘Check’ and ‘Report quality’
– review the text output
Mesh quality is very important to getting a converged, accurate solution. The User Guide suggests that maximum cell squish and skewness should be below 0.95, which the mesh here obeys. The maximum aspect ratio is 34, which is high, but acceptable in inflation layers. If the mesh quality is unacceptable, it is best to remesh the problem before proceeding. There are other possible remedies in FLUENT, such as conversion to polyhedral cells.
WS1-10
April 28, 2009 Inventory #002601
WS1: Mixing Tee
Cell Zone Conditions
– change the material it contains to ‘water-liquid’ – accept all other settings
– select ‘Edge Type’ to be ‘Feature’, and press ‘Display’ and then ‘Close’ – mesh has scaled, so press ‘Fit to Window’
• Adjust the view if you like
– in rotation mode:
– select ‘Temperature’ to be ‘c’ (Celsius) – press ‘Close’
Workshop Supplement
FLUENT stores values in SI units. Most postprocessing can be converted to other units.
Workshop Supplement
• Drag the existing mesh into the FLUENT analysis
You can see that the mesh needs to be updated, because its status icon changes.
– then Update the mesh (via Right-click) to convert the mesh format
WS1-5
April 28, 2009 Inventory #002601
WS1: Mixing Tee
Mesh scale and check
• In the ‘General’ task page, press ‘Scale’
– select ‘Mesh Was Created In’ to be ‘in’ (inches) – press the ‘Scale’ button (once only!) and ‘Close’
ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved.
WS1-3
April 28, 2009 Inventory #002601
WS1: Mixing Tee
Start a FLUENT case
• Drag a FLUENT analysis into the project
One or more graphics windows will be available (shown here with reduced size)
The console window displays text, and can accept TUI (Text User Interface) commands
ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved.
WS1-2
April 28, 2009 Inventory #002601
WS1: Mixing Tee
Start in Workbench
Workshop Supplement
WS1: Mixing Tee
FLUENT interface
The main commands are reached from the navigation pane
Workshop Supplement
Each item in the navigation pane brings up a new task page. A typical workflow will tackle these in order
Workshop Supplement
• Double-click on Setup to launch FLUENT
– click OK on the FLUENT Launcher screen
ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved.
WS1-4
April 28, 2009 Inventory #002601
ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved.