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Let's Talk Aero

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Kyle is the guy we worked with on our new wings, diffusors, canards, end plates, splitters and tunnels, and some other stuff right before he went to F1.

Great idea! Let's fix everything wrong about aero on the interwebs! I would start here...

I thought the direction that circulation bubbles rotate was obvious. I was wrong.
48015041412_3d3f8f8e70.jpg

Understand the difference between Adverse Pressure Gradient and Flow Separation. Don't use one to sound smarter than the rest of YouTube.
48014964883_769ce77710.jpg

And I'm not sure where to start with this one:
48015041257_1aa414e8b4.jpg



Somehow, I don't think he's talking about your posts. ;)
 

Grant 302

basic and well known psychic
Oh I'm sure he does. Everyone does. But he has a better grasp on aero then 99.99% of people. So I'll trust him and feel I am extremely fortunate to have worked with him.

So he was the one that did some of this work for you?
AJH 1 underbody tunnels a.png

There's a lot that's wrong with this comparison.

And "better grasp on aero then 99.99% of people" would put him at one in 10,000. Honestly, he doesn't strike me as much smarter than average, if that.

And most smart people I know don't need to furnish video proof of being smart:
Kyle diploma?.png

Just saying.
 

Grant 302

basic and well known psychic
Oh, it does matter when you make a comparison using different ride heights, splitter shapes, splitter profiles and don't make a proper comparison changing only the single element in question.
AJH 1 underbody tunnels.png

There's a lot that was changed between these two comparisons...care to explain that?

Please explain your opinion. I believe you were the one a page or two ago that said splitter angle doesn't matter? I have CFD sims, as well as actual in the wind tunnel experience debunking that.

In the context of flyhalf's add-on lip, I stand by that statement. Most, if any change comes from vertical movement of the leading edge.
 
View attachment 8783

And the more I look at this, the worse it seems. Looks like the tunnel itself would net a lift reaction.
False. Despite the fact that the pressure raises in the trailing part of the tunnel, the net Df gain is to the tune of almost double that of a flat splitter. CFD numbers support that. The ride height and rake of the main splitter body was the same in that side by side shot. Its mainly to show how much of a gain tunnels can have.

Oh, it does matter when you make a comparison using different ride heights, splitter shapes, splitter profiles and don't make a proper comparison changing only the single element in question.


View attachment 8782
In the context of flyhalf's add-on lip, I stand by that statement. Most, if any change comes from vertical movement of the leading edge.
Again, I would much rather have a splitter that has some forward rake to it and be 3" off the ground, then one with negative rake and be 2" off the ground. You do you tho.
There's a lot that was changed between these two comparisons...care to explain that?

Yes, as mentioned above, its to show the differences that adding tunnels can make to flat splitters. The tunneled setup made about double the downforce as the flat splitter
 
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Grant 302

basic and well known psychic
False. Despite the fact that the pressure raises in the trailing part of the tunnel, the net Df gain is to the tune of almost double that of a flat splitter. CFD numbers support that. The ride height and rake of the main splitter body was the same in that side by side shot. Its mainly to show how much of a gain tunnels can have.

Look at the red lines I inserted in the comparison drawing above. The lines on both are copy pasted, so they're the same angle and length. There are clearly differences between the two in both rake and ride height that have nothing to do with the tunnels and greatly skew the way this appears to the lay person.

Again, I would much rather have a splitter that has some forward rake to it and be 3" off the ground, then one with negative rake and be 2" off the ground. You do you tho.
Not even sure what you mean there.

Yes, as mentioned above, its to show the differences that adding tunnels can make to flat splitters. The tunneled setup made about double the downforce as the flat splitter
Again, I disagree with this one. But you can do stuff your way if you want. Doesn't bother me at all.

Then it either fails to show what you intend or is outright deceptive. And that does bother me.

Even his own analysis says not to put a diffuser in front of a tire:
Kyle said:
13:57 to 14:17
If we look at these side channels, look at where they're venting. This one here vents almost immediately into the tire. Now, if you're sort-of diffusing your air up, and then it's hitting this high pressure area on the front of your tire that's very turbulent, are you really getting an advantage here? (dramatic pause and hand gesturing) ...not really.

Kyle said:
14:26 to 14:34
But, if you can, try and avoid venting a diffuser into a tire, or anything like that. It's really not gonna do that much for you.


Not aero related, but this was one of the first video's I saw of his. The whole 'experiment' is invalid and pointless and completely ignores any understanding of modern, computer controlled IACs and TBs.
 
Look at the red lines I inserted in the comparison drawing above. The lines on both are copy pasted, so they're the same angle and length. There are clearly differences between the two in both rake and ride height that have nothing to do with the tunnels and greatly skew the way this appears to the lay person.


Not even sure what you mean there.



Then it either fails to show what you intend or is outright deceptive. And that does bother me.


Even his own analysis says not to put a diffuser in front of a tire:
Kyle said:
13:57 to 14:17
If we look at these side channels, look at where they're venting. This one here vents almost immediately into the tire. Now, if you're sort-of diffusing your air up, and then it's hitting this high pressure area on the front of your tire that's very turbulent, are you really getting an advantage here? (dramatic pause and hand gesturing) ...not really.

Kyle said:
14:26 to 14:34
But, if you can, try and avoid venting a diffuser into a tire, or anything like that. It's really not gonna do that much for you.


Ride height in CFD is based off chassis height since we were doing full chassis runs and could add rake to the entire chassis. So the tunneled splitter had a radiused edge to feed more air under the splitter, hence the splitter being a little lower with a small rake at the rear, but ride height the same. Hope that makes sense. And rake is the tilt or angle of either the splitter or chassis. Not quite sure how you feel this is deceptive as we are literally showing the pressure plots of CFD work we've done.
 

Grant 302

basic and well known psychic
Ride height in CFD is based off chassis height since we were doing full chassis runs and could add rake to the entire chassis. So the tunneled splitter had a radiused edge to feed more air under the splitter, hence the splitter being a little lower with a small rake at the rear, but ride height the same. Hope that makes sense. And rake is the tilt or angle of either the splitter or chassis. Not quite sure how you feel this is deceptive as we are literally showing the pressure plots of CFD work we've done.

ajh-1-underbody-tunnels-png.png

The marks on this drawing say otherwise. The bottom surfaces are pretty clearly different angles/rake.

To show what tunnels will do on a flat splitter, they should be used/tested on a FLAT splitter. Seems pretty simple in concept to me.
 
This thread is back open. I deleted a few posts but left most of the debate. Let's keep moving forward.
 

Mad Hatter

Gotta go Faster
5,237
4,227
Santiago, Chile
sigh..... the only wind I want to talk about here is the kind that physically affects our cars!! My engine blew up before I could fool around much with splitter angles... But I went from 1:10.18 to 1:10.11 with about -5 degrees of splitter angle :D Lol... but to early to tell.....
 

Bill Pemberton

0ld Ford Automotive Racing Terror
8,424
8,350
Exp. Type
Time Attack
Exp. Level
20+ Years
Blair, Nebraska
Dang need to adjust my bifocals, I thought this thread said, " Let's talk Oreo, " so I was figuring folks would be discussing whether one should suck out all the double stuff when dunking in milk, or if there was an osmotic effect if filling left in the middle. Yeh, I am just a splitter, separating those two dark cookie outers to dunk to my hearts content!
 

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