Submitting all four homework assignments will qualify you for a free Professional Training (value of 500€) as well as a SimScale Certificate of Completion.
Homework 4 - Deadline: Date, 31st of December, 11:59 pm
Homework Submission Form
For this last session of our workshope series, we want to challenge you guys and see the skills that you have acquired during the last 4 weeks, for this homework we want you to design your own front wing for Formula SAE, and test it using SimScale by following the same setup and steps in the the 2nd homework tutorial.
Your task is to design your own front wing and combine it with an existing car model, (the same model of the previous homeworks).
To start this exercise, first of all you need to have your own CAD software to model the front wing, no restrictions in term of CAD software you can use whatever you want,
You can download the car model without the front wing, by importing the project into your workbench by clicking on the link below. Please note that this can take some minutes.
This tutorial provides you with two different files:
1. Car model without front wing STL
This is a model in STL format which will later be merged with your front wing model. As discussed in the fourth webinar session, we recommend to prepare a STL master model for your own CFD process with SimScale.
Car model without front wing STL
2. Reference Geometry
To make sure that your front wing is in the right position we provide you with a reference mode in STEP file format, which you can import to your CAD system. Please make sure to keep the origin of the file.
The goal in the end is to create better designer than the existing one, the objectives of this homework is to creat more downforce with high efficiency, but this design have to be regulated by the FSAE regulation.
For more information s about Click on FSAE regulation.
For successful simulation we suggest the following things:
Make sure that you create a clean geometry, this mean you have to make sure that your model is watertight, closed volume (no open surfaces or edges we recommend to use solid modeling to make sure that you will have a closed volume), avoid intersections and overlapping of surfaces when you create your CAD, if you do have an existing model and you want to test it, please clean it up first defeature it and cut all the construction details like screws boltsand logos …, and make sure that you close all the open edges and hols in the surface.
Check the following picture to see how clean model looks like from an unclean model for CFD
To run simulation on SimScale it’s recommended to use STL file, that’s why you have to convert your CAD model into an STL model, in some CAD software when you export an STL file you will lose the identity of the parts and solids, and you will have only one solid for all the parts, and that's why it's important to follow the following steps to make sure that you will have an STL file with different parts, where you can apply different mesh refinements levels.
Create your CAD model with different parts.
For reference model download the exciting front wing CAD model Front Wing
STL file export
For the export it's depending on the CAD software that you are using, but generally here are the most common approaches to export different STL files for different parts.
Some software keep the same identity of the parts using colors when you convert the CAD model to STL model, and if you are using this kind of software you will not find any problem just select adjust the tessellation of your surface to high quality tessellation, to give an accurate representation of the curvatures, for STL files there is tow types STL ASCII and Binary choose STL ASCII format and name your file and export it.
For the other software you have to export a different files for every part, this can be done in tow ways.
By selecting specific part and export single part per file, and doing the same settings as before adjusting the tessellation to high quality Format to ASCII and name the file and export it to the specific folder.
Or for other software you have to hide all the other parts, and keep only the part that you want to export, and export it with the same setup.
To illustrate this you can see this example (the following steps can change from software to another).
- Choose the Format of you file to STL.
- Select ASCII format for the STL file.
- Please make sure that you have built your model using meter unit otherwise scale your model to [m], the unit of SimScale is meter [m].
- Really important point adjust your tessellation to good quality using automatic adjustment or customize it.
- If you have this function in your software of exporting STL with multi parts, activate it otherwise follow the above steps.
- Finally name your file and export it.
- In result you will get a file for every part.
Merging the STL files
Now we have to merge all the STL files (your front wing design and the car body) into one file to do this we provide you with a script that will do this step automaticlly for you.
First of all creat new folder and name it FSAE 4th session optional.
then Put all STL (your front wing design and the car body) files inside the folder which you want to merge.
Download the script file from here Script file download
Now put the script inside the folder FSAE 4th session
to merge all the STL files in the same file you have to run the script to do this (rightlick on file Merge_STL, and run with PowerShell).
Then new window will show up click on open.
- The merging process can take up to 20 min, after this you will have a new file in the folder FSAE 4th session, contain all the parts together in one file.
Using text editor (alternative)
Merging the STL files can be done using another option by editing the STL file it self, to do this you need a text editor. in case if the script does not work for you we suggest this option as an alternative.
As you know from the last session of our home work the STL file will start with solid name and finish by endsolid name.
All what you have to do is to open new text file, and open the other STL files using your text editor and copy past all the information from the STL files into the new text file.
To do this follow the next steps:
Right click on the first STL file and choose Edit with (your text editor)
New window will open of the text editor.
Click on the first line solid name, scroll down to the end of the text, press Shift and click on the last line in the text, ( make sure that you selelct all the text).
Copy the file Ctrl+C and paste it in the the empty text file that you have created using Ctrl+V.
Repeat the same steps with the other STL files, but this time you have to paste the STL text after the end of the previous text in the new folder.
Do the same steps with all the files of your front wing and the car model, and you will endup with a file contain all the car parts in diffrent solids.
As soon as you finish from this step save the file with the name of the file, but make sure that you add the extension .STL
Creating project on SimScale
Now we have the full model with your front wing design and the car body, it's time to move to the next step, Uploading the new STL on the platform.
To do this go to www.simscale.com login in your account by clicking on LOGIN on the top right corner, and enter your login information.
Then on the Dashboard click on New project in the top right corner.
New window will show up, fill the informations on the window, the title of the project a description of the project choose the category of your project, and you can Drag and drop your CAD files, or select the file from the folder, (select the last file where you have merged all the STL files together).
Uploading the file can take some time, depending on your internet connexion speed.
When you finish click on Creat new projet, and you will finish the import steps.
For mesh generation and setting up the simulation you can follow the same steps of the 2nd homework