End of May I had the exciting opportunity to support Diego Poncelet on a wind tunnel test day in Geneva. Several different helmets, suits, appendices and positions were tested. A total of 66 sessions at 20 seconds each were recorded. We were handed a USB stick containing numerous folders with spreadsheets and two videos per session, a side view and a frontal view.
In order to compare the results, I put together a summary gathering all results in a single Excel file with a tab per session. The main number we look at is the coefficient of drag (SCx). A graph shows the SCx over the period of 20 seconds.
Each spreadsheet has a link to the two videos of a session. To avoid having to go back and forth between spreadsheets and a videos, the SCx was added as subtitles to all of the 132 videos. To be able to look at the Excel summary platform-independet, the Excel spreadsheet was exported as *.htm file and uploaded to a password protected directory on my server.
The videos show position changes and hence allow us to judge the quality of the results. To facilitate comparing the coefficient of drag at a given time in two videos simultaneously, the frames of the videos were exported and a website with image overlays was programmed.
Two tests can be selected with dropdown menues. The + and – buttons can be used to jump to the next or previous image. The website is responsive and works both with a mouse and touch on mobile devices.
A big thank you to Diego Poncelet and the team at Hepia.
There will be more content shared about our collaboration in the near future.
As a start, here’s the video from RTS Mise au point from 18. June 2023:
Our helmet prototype was created with a 3D printed mold and laminated in carbon and kevlar by Aaron Skippings. The helmet weighs in at around 900 grams. The project is featured in Easy Composites customer gallery:
Downhill Skateboarding Helmet – Easy Composites
The project is mentioned in my case study on 3D scanning with the Artec Leo in industrial design / product design with Swiss Artec distributor 3d-model.ch