Skip to content

Create an optimisation run

An optimisation run simulates many deformed variants of a Part in one Run. Every variant uses the same conditions, taken from one Attitude of a Map, and differs only in its deformation magnitudes. See optimisation runs for how it works.

Before you start

  • The Part needs a deformation volume with at least one parameter, and at least two for a Latin Hypercube. See create deformation parameters.
  • The Programme needs a Template Case and a Map. The Map provides the conditions, such as velocity and ride height.
  • Select a Programme and a Project in the header.

1. Start the run

  1. In the sidebar, under Simulation Admin, click Runs.
  2. Click Create Optimisation Run.
  3. In Create Optimisation Run, fill in the Run's details as for a normal Run (see create a Run), then:
    • Map: required.
    • Attitude: the Attitude whose conditions every variant will use. It's chosen for you if the Map has only one. The selected Attitude is copied to a new optimisation map, and the Map's other Attitudes aren't used.
  4. Click Pick Assemblies and choose the Assemblies. One of them must contain the Part to deform.
  5. Click Configure Optimisation. The viewer opens.

2. Choose what to deform

Work down the sidebar steps: Assembly, Part, Volume, Parameter. Any step with only one option is selected for you. Only volumes that have parameters are listed. You can also click a Part in the viewer to select it.

Select the parameters to vary. Bramble chains them in the order you select them, and that order is fixed for the run. Hover over a parameter to highlight the control nodes it moves.

3. Fill in the optimisation table

Click Configure Optimisation Table. Bramble loads the mesh node locations, which can take a few seconds, and opens Parameter Optimisation. Each row becomes one Attitude of the optimisation map.

Add rows by hand. Click Add Attitude to add a row named "Deformation 1", "Deformation 2" and so on. Enter each parameter's magnitude, and edit a row's name directly in the table.

Or generate rows. Choose a method, set its inputs and click Generate Optimisation:

Method Inputs Rows generated
Latin Hypercube From and To for each parameter, plus Detail Level Detail Level × number of parameters, spread across the whole parameter space. Needs at least 2 parameters
Linear Sweep From and To for each parameter, plus Number of Points (2–50) Number of Points, with all parameters moving together in even steps from their From to their To values

See the morphing reference for defaults and limits.

Generating replaces the table

Generate Optimisation deletes every existing row, including rows you added by hand, without asking.

Check and adjust rows. Each row has: - Visualise Deformation, to preview that variant in the viewer - Edit Attitude - Copy Attitude - delete

Drag rows to reorder them. To play every row as an animation, click Configure Visualisation. Reset Part returns the viewer to the undeformed Part.

4. Create the map and the run

  1. Click Create Run.
  2. In Confirm Creation of Map, enter a Map Name for the new optimisation map.
  3. Click Confirm.

Bramble creates:

  • An optimisation map. Its first Attitude is the baseline: the Attitude you chose, with no deformation. Each table row follows as another Attitude.
  • The run, using that map. Set up each Attitude's CFD and launch as usual. See launch and monitor a Run. The deformed Parts are generated automatically when each case is set up.

Edit the optimisation map

Optimisation maps are hidden on the Maps page until you turn on Show Optimisation Maps:. The switch only appears once an optimisation map exists.

In the map editor, only the baseline Attitude's normal parameters, such as ride height and velocity, can be changed. Changes copy to every other Attitude. The other Attitudes differ only in their deformation magnitudes. The baseline can't be deleted, and optimisation maps can't be copied.

Change magnitudes after creating the run

On the Run's Summary tab, the Optimisation Parameters section lists the parameters being varied.

  • Click the eye icon to open View Optimisation Parameters, which shows each Attitude's magnitudes and transformation types.
  • Click the edit icon to reopen the viewer and change the magnitudes of Attitudes that haven't been launched. Then click Update Map. The new values are saved to the optimisation map. You can't add, copy or delete Attitudes here.

Start a new run from an existing optimisation map

Choose an optimisation map in Create Optimisation Run. Bramble selects its baseline Attitude and preloads its deformation rows and parameters into the table, so you can run the same design of experiments again, for example on another Assembly.

  • The map must already be attached to a Run: "To use a predefined optimisation map, it must be attached to a run."
  • The Assembly must contain the same Part. Otherwise creation fails, for example with "Could not find part in assembly."

Related: Morphing reference · Deform a Part