Simulation - Vizualisation

 


Simulation parameters

In the node Implicit Unsteady

set up the Time-step. Here, 0.05s is used.

In the node Stopping Criteria the user has to define the conditions which will make the iterations stop : the logical rules are

  • OR : if the condition is satisfied, it does the action.
  • AND : if the condition is satified, it still iterates until all AND conditions are satisfied or a OR condition is satisfied.

Here, two condition are enabled :

In conclusion, the software will do 20 inner iterations for every 0.05s time-step until it reachs 100s.

 

Now, the idea is to save simulation results, let's say every 0.1s to make an animation for example. Right click on Solution Histories $\rightarrow$ New $\rightarrow$ "load". In fact, the results wanted will be solved in the "load.simh" file.

Right click on load $\rightarrow$

That means : when the simulation reachs 70s (the transcient part is not wanted here) the scalar and vector functions chosen (Pressure, TVR and velocity) in the moving_region and domaine are going to be saved in "load.simh" every Delta time =0.1s until the end of the simulation (100s).

Now that everything is set up, one can initialize and launch the simulation . It could be a good idea to launch starccm+ in background with a batch java function and the "nohup" shell command.

 


Create a Visualization

Now that the simulation is done, let us visualize the solution :

To do so, create a scalar scene : right click on Scene $\rightarrow$ New $\rightarrow$ Scalar. 

With this scalar node "pressure", the pressure on the wind turbine is seen. Now, to see the wake on this same scene, the Turbulent viscosity ratio is used. Two choice are possible :

  • add a TVR isosurface
  • add a resampled volume (which is the choice done here)

The second solution will be explained here :

right click on Derived Part $\rightarrow$ Resampled Volume. The idea is to place this volume where the wake should actually be : after the wind turbine.

Now in the same scene as before, in the scene/plot onglet () Right click on Displayer $\rightarrow$ New Displayer $\rightarrow$ Scalar. Here, as a part select the resampled Volume and as a scalar the TVR. In the scalar field properties, disable the Auto Range.

Add a solution time annotation to the scene by draging Solution Time to the scene : Tools $\rightarrow$ Annotation $\rightarrow$ Solution Time. (This way, it is possible to add logos to the scene as well. Create a new 2D image annotation).

Now, it is easily noticeable that only the solution at the last time is seen. To have access to the solutions stored in "load.simh" : Solution Histories $\rightarrow$ right click on load $\rightarrow$ Create recorded Solution View. In the node Solution View, drag "load" to the scene.Here

it is possible to choose the State visualized.

StarCCM+ makes it possible to create a video *.avi of the solution :

Solution Views $\rightarrow$ Load $\rightarrow$ Animation $\rightarrow$ Solution time $\rightarrow$ Solution Time animation. In the Solution Time Animation Properties, choose the length of the video, the starting time and the ending time :

In order to record the animation, click on record (the right button here ).

Then be careful to define the same animation length as before :

 

Eventually :