# Step-by-Step Tutorial: Homework of Session 3

#1

## Homework submission

Submitting all three homework assignments will qualify you for a free Professional Training (value of 500€), a certificate of participation and will give you a chance to win a special price!

## Exercise

With this homework we want to put you into the seat of a F1 race car designer.

Your task is to perform a flow simulation of your own rear wing design which you can create with the
parametric model we provide. For this you have to do the following steps:

1. Modify and export the parametric rear wing model with CAESES Free. The exact instructions for this can be found below
2. Setup a external aerodynamics analysis of the wing for 40m/s, 60m/s and 80m/s. Please use the same simulation setup from the previous homework assignement

## Step-by-Step instruction:

In the following step by step tutorial you will understand the basic operations to manipulate the graphical user interface to modify the given geometry.

Note: The colors of the rearwing surfaces can may be different

The 3D view window it’s window that we can use to visualise and manipulate our geometry, the lower bare contain functions that facilitate the manipulation operations.

Zoom operations can be used to fit the view of your model in the center of the graphical window, you can click directly on this operation or you can reach it by the keyboard key F10.

The filters allow you to show or hide a specific entity like points, lines, surfaces or Breps by clicking on the specific type you will hide the selected entities.

This function allows you to show the mesh of the geometry.

This function is to create a symmetry image for the geometry, like in our model we have half model and we can use this operation to create a symmetric image to see the full model.

This operation gives you the possibility to create a view projection along a specific axe like is shown in the icons.

To open an existing mode using CAESES click on file > open project then search for the file of your model in the specified path where you have save it or directly using Ctrl+O commend.

When the model is opened you can see it in the 3D view window if it does not appear in the 3D view window, you should just click on zoom extended or press F10 and the mode will be centered in the center of the window hide also points and surfaces and click on symmetry image to get full 3D model.

This model is parametric model designed using metasurface technique and the distribution of these parameters in the wing span wise is controlled by functions that we have to visualize it to do this right click on overview then select 3D over view, a new window will appear in the lower part of your screen.

On the new window click on surface, BREP and mesh filters to show only the lines and the points then click on +z projection view to have plan view, you can turn your view to the right axes using the arrows key with the key board.

Now you have the functions and the 3d model view you can manipulate the functions and see how the functions influence the model.

To do this you have to decide which parameter you want to change, go to the specific function and select one or more points from the function that you want to change, keep holding the selected control points and move your mouse in the X or Y direction and you will see you model moving at the same time.

Once you finally modify your model as you want now it’s the stage to save the model and to export it to run it later in SimScale.

To save your model click on File > Save specify the path where you want save you file. To export your model click on File > Export then you will have a large library of formats that allows you to export surfaces and meshes for our work we will use STL (Multi Body) to use a model with separated boundaries.

Please create a new public project.

Then open the project and switch to the Mesh Creator

There you will find some information about the dimensions of your CAD model. Since the (the orginal model was created in milimeter we will perform a scaling operation. Please click on the Add geometry operation button.

Choose Scaling as the operation and define a Scaling factor of 0.001. Please change your changes and start the operation.

Now you can continue with the instructions of the last homework assignement.

Step-by-Step Tutorial: Homework of Session 2
#2

#3

#4

I can’t see the geometry or the caeses file for this homework. Do we have to create it on our own?

Unai

#5

Hi Unai,

https://seafile.simscale.com/f/8d0e91c0f5/?raw=1

Cheers,

#6

Unai

#7

The description of the tutorial steps doesn’t seem to correspond to the model you have linked to.

Firstly the model is only half a wing, which i appreciate is not necessarily an issue.

However when I try to follow the steps in the tutorial i don’t get the lines and points showing up, so i can’t edit them.

I am very keen to complete the tutorial, however i’ve already wasted time getting this new program to download and run, and now i can’t complete the tutorial anyway

#8

Ok, I followed the procedure, got the new model, mesh done, But after that, running the simulation started to give wierd convergence plots and midway my simulations stopped and showed the error, not enough memory.
I think I may(most likely) made a mistake somewhere, but now can’t figure out whats wrong.

#9

Yup, that software is really slow, and for every modifications i tried to make(camber, chord etc.), the response was pathetic, I am still trying to figure whether it is my pc or the software. However, i am not getting my result converge anyway.

#10

did the model you downloaded include all the points shown in the images in the tutorial?

#11

Yes they did,

If you mean this?

#12

Yes. The model I have tried to use doesn’t have those.

https://seafile.simscale.com/f/8d0e91c0f5/?raw=1

Can’t show a screenshot as it is on a different computer

#13

Hi,

First of all thank you for your comments and reaching out to us.

@rahulsharma_94
Your setup for mesh and simulation are looking good! It seems that there are some issues with the mesh for specific parameter of the model. We already found the reason and fixed it. We will therefore provide you tomorrow morning with a new CAESES model which will export a full (non-symmetric) stl. This will avoid problem is the future.

@aedwards
The file and the link are okay. Nevertheless, working with parametric models can be very complex. We will therefore update the tutorial and create a video tutorial

Here are some screenshots of the new model:

Cheers,

#14

Where do I get the CAESES software?

#15

#16

ok, thanks, this is what i get when i use the model and follow the steps described:

There seems to be a single set of points, but they don’t line up with the geometry of the wing and there are no labels.

#17

zoom towards the origin. Try filter points and lines, then F10. Turn back on the line and point filter.

#18

Hey Milad, could you tell me what was the exact problem ,so that in future I can identify any problems I may face.

#19

Thank you for your help. I have now managed to find and change the parameters

#20