Dr Obbs Profile picture
Mar 9, 2022 11 tweets 9 min read Read on X
The rumors about the @MercedesAMGF1 being updated without a side pod and comments to @ScarbsTech mad scientist Merc drawings, showed me some explanation of the aero influence side pods have is worthwhile. So let's dig more into this #F1Tech thread.

📸(Stefan Baldauf) #AMuS
For open wheel racers, one especially problematic geometric element is the front tires. A source of drag, and wake turbulence, the control of the front tire wake is essential for aero efficiency. A great study of this can be found below racecar-engineering.com/articles/wheel…

#F1Tech
There are three primary turbulent structures around a rotating wheel. From the referenced study, the influence of the front wing can not be ignored, so the results presented are generally present but can be different as teams design the front wings differently. #F1Tech
At 1 Diameter downstream, we can see the counter rotating vortex pair. We also see the tendency of the tire wake to be pulled inboard towards the floor, and venturi tunnels which is not ideal. #F1Tech
So what's new? Tire wake is not new, but how teams manage it is for 2022. In previous years teams would use a system of barge boards to straighten and deflect the incoming air conditioning it for their aero package. #F1Tech
For 2022 regulations have essentially eliminated the barge board in it's old forms because it created massive wake profiles. In an effort to clean up the wake for following cars, teams now how to decide how to manage this front tire wake. #F1Tech

(CFD credit @AeroGandalf )
Although barge boards are not present, Some teams are using bluff side pods to create outwash that helps to push this front tire wake outward. Different teams employ different methods, but the concept is similar.
📸 @SportmphMark formula1.com/en/latest/arti…
The aero tradoff can come in the form of additional form drag from the bluff side pod. However, trade-offs must be made as front tire wake not deflected can significantly increase drag on the rear tire as well. #F1Tech
Teams are also employing different designs for the outboard floor strakes to try and protect these venturi tunnels from dirty air. I see this as an area of innovation as the year goes on. #F1Tech
There are a host of other reasons mechanically and structurally for side pods, but I hope this aero influence review helps you to see what role they play as well. Further reading can be found at the references below. #F1Tech

racecar-engineering.com/articles/wheel…

f1technical.net/features/22288
For other great #F1tech follows, be sure to check out the accounts for

@NaturalParadigm
@TimoteoBriet
@AeroGandalf
@BeschadigunC
@NorthHertsSam
@SportmphMark
@FiratKeskinF1

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Dr Obbs

Dr Obbs Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @dr_obbs

May 28
Lots of talk about tyre degradation, tyre temps, balance, and the like. So I think it's time for a refresher course on tyres, grip, and degradation. I'll try and cover all of this in this thread, but stay at a high level (because it's incredibly complex) for general understanding.

Firstly, we should understand that as a car goes around a corner, the input angle of the driver to move the tyre relative to the direction of travel creates a slip angle. This slip angle creates the forces at the contact patch that act to rotate the car about the Center of Gravity (CoG) through the corner (moment).Image
If we focus in on a single tyre, then we see that with increasing slip angle (with constant Normal Force), the lateral force to turn the car is increasing until a limit (sliding limit). After this point, increasing slip angle will result in less lateral force, as the tyre is no longer able to impart a force at the contact patch without sliding.

The rubber tyre behavior plays a key role in this as well. In the initial stressed region, the rubber acts as a linear elastic material with increasing slip angle (Figure in the middle). At a point, this transitions to an intermediate phase where the rubber acts non-linearly. This non-linear stress response generates a hysteresis within the material that manifests itself in a heating response. This is termed hysteretic heating, and can be a key to generating bulk tyre temperatures.Image
The grip at the contact patch is greater as the load at the patch is increased. This means that the lateral force that can be generated from the same tyre is greatly increased with increasing normal force. This is why downforce for race cars matters so much. As you increase the load, the turning force that can be applied is increased, as well as the load limit for sliding at increasing slip angle. The coefficient of friction between the track surface and the rubber plays a key element in this as well. With different track types, the surface has more or less grip potential. Essentially more or less coefficient of friction.

Ref. image (suspensionsecrets.co.uk/tyre-slip-angl…)Image
Read 8 tweets
Mar 13, 2024
People often ask me, "where can I find great information on motorsports and aerodynamics?" So how about a thread of some of my favorites? And no, I don't get paid to endorse these. I just think F1 Tech is a great place to share knowledge! Also, this is NOT an exhaustive list, but some that stick out to me. Feel free to add yours as well below!

Video below by Vyssion and JJN.
Let's start with some of my favorite books on car aerodynamics! "Race Car Aerodynamics: Designing for Speed" by Joseph Katz is goated. A really great book covering all types of race cars and written for anyone at any level. I highly recommend this book. Image
Another book that is sort of an extension of Katz is one from Simon McBeath called "Competition Car Aerodynamics." It's like a newer version of Katz book, and with a bit of very simple CFD in it as well. Image
Read 17 tweets
Mar 4, 2024
Is the RB20 great? Or is Max Verstappen + the RB20 great? I spent some of the weekend looking through the telemetry. And here is what I have found. In summary, Max Verstappen is a Swiss f*cking watch. Well, maybe a Dutch watch. Let's look at it in this thread. Image
Looking at the macro view level lap times to gage consistency, you can see that it's incredibly consistent irrespective of compoud. Credit to Checo as well, his lap times in Bahrain were also very consistent, but also consistently 5-tenths to 1 second slower per lap. But why? Image
Looking over the a single lap, many show similar characteristics. It's like death by a thousand paper cuts, or in this case by 15 corners. The intricacy and precision of driving from one corner to the next builds delta from corner to corner. Image
Read 13 tweets
Jul 12, 2023
Was the RB19 of MV really slow on the straights compared to the other teams? Or was something else going on? We know that MV wasn't fortunate to gain any DRS or slipstream after passing LN, but what else was going on? Let's understand this more in the thread below. 🧵
If we look first at the pit straight into Turns 1 and 2, comparing LN and MV, we see something peculiar. MV never upshifts to 8th gear, but holds 7th. Thus, his engine RPM is higher and he doesn't lift into T1. He does, however, lose time slightly to LN due to the lower speed. 🧵
Looking at the onboards, LN is 1.336s behind MV so he may catch a very slight tow, but the top speed delta here is 4kph with LN reaching 300kph. By MV never upshifting to 8th gear he limits his T1 entry speed, but doesn't have to lift as a result. 🧵
Read 11 tweets
May 31, 2023
Well that helps to solve that mystery. Had also heard that this plank was painted so they could observe the wear patterns better. Looking at this, the plank wear is quite low overall. How about a thread comparing my observations of the RB, Merc, and Ferrari wear patterns.🧵
The bib looks to be running quite low. Possibly some forward rake, as most suspect. RB is able to run their forward floor very low, and still ride curbs and manage bump tracks like Monaco. A bit more left sided mid wear. 🧵 Image
Mid floor looks pretty stable with little wear. Same preferential left side wear from previous image along the length of the mid floor. No floor flexing going on here. 😉 🧵 Image
Read 7 tweets
May 30, 2023
There is a quote in here that perfectly summarizes what I have been trying to say about the complexity seeing an image of a floor, and then getting a floor to work well.

"Talking to an engineer from the Milton Keynes team, not too worried about the photographs taken of their.."
"..underbody in Montecarlo, he explained to us that it is easier to work on the cross section of the channels while the slope (height) variation part inside is much more complicated to the tunnel and the simultaneous generation of eddies; an infinite job, among other things.."
".., since a car never works with a constant height but has many external elements, such as bumps, and dynamics, such as roll, pitch, etc., which greatly complicate the design of what it is the most important aerodynamic component of these new F1 cars..."
Read 4 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us!

:(