This article helps explain the steps to create surrogate models and use them in optimization studies instead of using simulation results in the optimization search process. This could be helpful in reducing overall time in some design spacesSTAGE 1: Creation of Surrogate model
Step1 : From version Simcenter STAR-CCM+ 2021.1, a new node called Surrogates will appear within every Design Study
Right Click on Surrogates and click "New Surrogate"
Step 2 - Choose the response for the surrogate mode
Here we have chosen Pressure Drop
Step 3: Once a response has been chosen, we can go ahead of compute the surrogate..
We will end up with a green tick mark like shown below:STAGE 2: Using this surrogate in an optimization study:
In this stage we will see how to use the Surrogate model created in previous study in a new optimization study with an objective.
Step 1: Create an optimization study and choose Evaluation Method as "Surrogates" not simulations
Step 2 : Now include the same input parameters used in the surrogate model created earlier and include the responses of interest
Step 3 :
Click on Response (ex: Pressure drop) and in the properties window, choose the surrogate model as shown below:
Check the box : "Is Objective"
Step 4 : Now we are ready to run the optimization study, Right Click and click "Run Study"
Once the optimization is completed, we can see the objective history where the pressure drop vs design iterations can be seen. Note that the design outputs are not from raw simulation files but from the surrogate model created earlier. So we can expect the whole optimization study to complete in seconds.