Aero analysis for F1 2022 based on CFD result

[Mchamilton]

That might be asking for too much precision from the CFD calculation, I think.

Yeah most likely

[Latios]

So with a vehicle velocity of 60 m/s does that mean in the venturi the air is moving at around 90 m/s, ie 60 m/s+sqrt(3000/(1.22*.5)) assuming the pressure there is -3000 Pa relative to atmospheric?

?

Firstly, I'm using air around 25 degree so the density is around 1.18
Then, actually it's 3d flow structual (vortex, separation, inward/outward flow), and has boundary layer ,so estimate based on 2d is less accurate.
But, I just check the data, the max speed is around the throat, and it's 94m/s, so good estimate!

[Latios]

Good job! I really liked the Red Bull and classical beam wing comparison, very insightful!

In my view, there is just a bit too many plots on the picutures, hard to read all the details. Might be easier to limit to two, maybe combine pressure/velocity plots and only one type of flow visualisation (vectors, steamlines, etc)...

Thank you for the advice, will consider to use less plots in coming updates!

[Latios]

Could you provide the data of the rear wing between your standard and RB style beam wings?
Interested to see if the top element does indeed protect the rear wing underside from the extra upwash produced by the RB lower elements.

The very upwash beam does harm the rear wing, but not much.
Rear wing profiles' downforce changes from 1696N to 1631N

[Latios]

https://pic3.zhimg.com/80/v2-6e2fee1079 ... 6_720w.jpg
https://pic1.zhimg.com/80/v2-d97eafbf99 ... 4_720w.jpg

So contraction section is almost to the rear wheel.
How air not increase static pressure in this contraction section?




https://pic3.zhimg.com/80/v2-6e2fee107 ...

1. There is vortex in the tunnel generated by outwash fences, the vortex is low pressure structual.
2. A little contracting could increase pressure a little but the diffuser's expansion rate make the contracting zone with low pressure in total.

[Latios]

Good work! Nice to see someone else doing this sort of analysis!!! If I were to offer a couple of (hopefully constructive) criticisms. When we plot contours we tend to use coefficients rather than absolute pressure (i.e. in Pascals) - and set between 1 (stagnation) and somewhere between -1 to -2 to give an idea of the suction but not lose fidelity. This will give a better understanding of what your contours mean as it's not velocity dependent.

You also don't give an aero balance - typically what we want to know in development is downforce, drag and how the downforce is distributed about the car - again SCz and SCx are better as they're not velocity dependent. You want 40-45% of the downforce pushing on the front axle.

You don't appear to be working the front of the tunnels all that hard, so I'd anticipate your balance is quite rearward. Have a look at the Haas floor from Saturday - the middle of the tunnels is sitting around Z50 (the bottom of the floor body volume) with a significantly shorter bell mouth - couple this with your fence design and you should get more load from the front of the floor.

Good work though!

https://external-content.duckduckgo.com ... f=1&nofb=1

https://external-content.duckduckgo.com ... f=1&nofb=1

https://www.racefans.net/wp-content/upl ... N-55-3.jpg

Thank you for the advice!
1. About not using Cp, because I'm a little lazy haha, and also computing Cp when ploting costs little more time, and absolute pressure is more direct. I had master degree of aircraft aerodynamics, during that time I was using Cp all the time. Will consider using Cp in coming updates.
2. About balance, I had data related to real axes, yes it's too backward, just didn't put it here. I haven't done more iteration, the floor front just have 3 versions: higher front without outwash, lower front without outwash(since higer front will have stagnation point too low at leading edge), lower front with outwash. Also I'm curious why the pictures you list can have so much downforce on floor front. Plan to find way to improve front floor, maybe by change fence position, maybe my inner fence is too close to middle body and cause separation (result in strong vortex under body), and also maybe 4.5cm ground clearance is too much, plan to reduce, also enlarge tunnel (such as to Z50 as you mentioned) to prevent separation with less clearance.

Thank you very much for the advices!
Are you auther of the the CFD article/pictures you listed?

[Latios]

@Lazio

Good job. I think it will take me a week to figure it out. As a non-technical, but simple enthusiast, I have a humble question to ask. You talked about porpoising. To solve this problem, I have observed that several teams have tried to increase ground clearance, at the same time losing efficiency and performance. The question is: How does RB lower the ground clearance of the car at the rear (just notice the sparks emanating from the bottom) and at the same time solve the porpoising problem and gain in terms of speed and stability on the straights? Maybe the answer is inherent in your post, and I have not been able to grasp it, but I ask this question on behalf of all those like me who are not aerospace technicians, but are fascinated by the subject. Thanks in advance.

There are 3 elements I can think of:
1. Redbull's suspension design, such as the abnormal front suspension, and the rear suspension whose detail we cannot see.
2. The floor edge design and also design of side of diffuser. The arc marked in C and D may have some tricky way to stablize the ground clearance of floor body. Plan to analyze it by CFD in coming days.
3. Tunnel shape. It may couple with item 2.

[Latios]

@Lazio

Good job. I think it will take me a week to figure it out. As a non-technical, but simple enthusiast, I have a humble question to ask. You talked about porpoising. To solve this problem, I have observed that several teams have tried to increase ground clearance, at the same time losing efficiency and performance. The question is: How does RB lower the ground clearance of the car at the rear (just notice the sparks emanating from the bottom) and at the same time solve the porpoising problem and gain in terms of speed and stability on the straights? Maybe the answer is inherent in your post, and I have not been able to grasp it, but I ask this question on behalf of all those like me who are not aerospace technicians, but are fascinated by the subject. Thanks in advance.

It surely must be to do with how they control the vortices under the car.
I wonder if the original poster would be able to run his CFD with the ground clearance super low and see if it ever shows vortices bursting as they pass through the throat of the tunnels.

I have the data of small ground clearance:

Maybe I should enlarge the tunnel then check difference, just time consuming.

[Latios]

That might be asking for too much precision from the CFD calculation, I think.

Yes, the main differences include:
corner flow direction (non-inertial frame, full model simulation rather than half)
Suspension position when in corner
Transient flow, variable shape and suspension at real time
Not enough mesh (F1 teams must use 100+ million)

If I get the luck to be hired by F1 team I can do much more precise analysis and design!

[tonino102008]

Thank you very much the content Latios. It's really interesting! Did you design the floor all by yourself or you started from an already available geometry?

[LostInTranslation]

If I get the luck to be hired by F1 team I can do much more precise analysis and design!

You did an amazing job. I wish you to be hired by one of the F1 teams. I would know the one in which I would like to have you. Hope someone reads us. Talent is always something you have to bet on, wherever it comes from. Again, I hope someone with straight ears will read us. And I know this forum is the best you can find about F1.

[godlameroso]

257N is just for the small fins(wing) mounted inside real wheel, so it's "real wheel wing"
rear profiles are what you looking for about "rear wing", in reg doc they are "Rear Wing Profiles"

Now is clear.
Can you post picture how shape of "venturi tunnels" looks from side view?
Or you can just draw a line at F1 car how tunnels looks from side, I am interested how convergent, throat and divergent section looks like..

1. Its flow structral is more comlex than traditional venturi, adding outwash/vortex.
2. My floor shape has a lot to optimize, it just meets the regulation and with outwash design.
https://pic3.zhimg.com/80/v2-6e2fee1079 ... 6_720w.jpg
https://pic1.zhimg.com/80/v2-d97eafbf99 ... 4_720w.jpg

[SmallSoldier]

Great job! That was a very good read! Made in a way that it is easy to understand!

Thank you

[Latios]

Thank you very much the content Latios. It's really interesting! Did you design the floor all by yourself or you started from an already available geometry?

I did all the CAD adn CFD by myself in spare time, from last year. The reg for 2022 is very strict and detailed so no much variety allowed.

[Latios]

If I get the luck to be hired by F1 team I can do much more precise analysis and design!

You did an amazing job. I wish you to be hired by one of the F1 teams. I would know the one in which I would like to have you. Hope someone reads us. Talent is always something you have to bet on, wherever it comes from. Again, I hope someone with straight ears will read us. And I know this forum is the best you can find about F1.

Thank you very much, it's soooo encouraging !
Doing analyze is very interesting and good way to kill time, feeling closer to the amazing sport.