How splitter tunnels and front diffusors work (CFD supported)
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- Опубліковано 23 лип 2024
- In this video we go over how splitter tunnels work. Thanks to JKF Aero (now working for an F1 team) for his work in developing these tunnels and splitter side plates. Please be sure to check out his channel for a ton more good aero videos.
Kyles channel:
/ kyleengineers
Links to parts mentioned in this video:
Small tunnels: ajhartmanaero.com/small-curve...
Large curved tunnels: ajhartmanaero.com/large-curve...
Straight tunnels: ajhartmanaero.com/straight-sp...
Louvers (can be innie or outie), and other vents and ducts:
ajhartmanaero.com/vents-ducts/
Blog: ajhartmanaero.com/blog/splitt...
love that this video came up on my recommended. Kyle seems to be really happy and doing some awesome work at where he's at. Especially since the team has been unbeatable
Was gonna say sure looks like some of Kyle's renders, nice ;) awesome video!
Great content, very informative. Hope to see more like this in the future.
Very informative and concise. please keep'em coming
Hey AJ thanks for the great video, keep them coming.
Awesome explanation about the Tunnels and Splitters - thanks so much.
good explanation of how to design a splitter diffuser if it has to go in front of the tyre. handy to know!
Thanks, couldnt find much info on splitter tunnles so this cleared up alot
Great video as stated by others! Thanks for the submitted genius to East Coast Road Racing Club ~!
Nice video, thanks for the great explanation
Well explained. I learnt something.
Learnt something new.
I'd like to know what improvement to lap times a flat floor will do.
How much drag does a shorter splitter create opposed to a splitter that goes all the way back past the front axle and up the the front subframe? I see a lot of splitter designs that are cut short for shipping purposes (save money) but is it worth the extra length?
Cfd and wind tunnel data on splitters is much more limited then wings. It will be a little more but nothing drastic. As with all things aero, the degree of it depends on several factors. Not sure if you are following our new Vlogs but my new splitter will be a seperate piece to extend it to the axle centerline and will test both setups with data.
What about vortices/pressures created around the spinning wheel, tire, and brake rotor?
They affect it for sure but to get into that is a whole other level of complexity.
@@ajhartmanaero yea, I think between you and this SAE paper I buckled down and paid for I learned it’s called tire squirt. I should’ve watched more of your vids before paying that 33 bucks lol.
This topic will probably get some traction with the 2023 Porsche GT3RS now having active wings in their front diffuser tunnels.
Just looked it up. Pretty neat. I’ve actually been tinkering with an adjustable splitter tunnel but would be a manual option since just about every rules set for racing dictates aero must be fixed.
Tire is spinning, creating a high pressure area and dirt air, have you evaluated how this affects a front diffuser?
Yes. Tire squirt was modeled in our CFD runs. Since the tunnel is in front of it, its not overly detrimental, but you also can't get away without tire squirt either so it is what it is.
@@ajhartmanaero I find the terms , high pressure and low pressure confusing. Is low pressure = less lift .... and high pressure = less drag?
Does the tunnel shape requirement change as the car experiences yaw?
Not under a normal yaw condition of only a few degrees.
So when the air moves it has a lower pressure? What if the air stays still and the car moves past the air?
Effectively the same. Theres a case for a non moving floor wind tunnel you'll get an extra boundry layer on the ground, but for the sake of this video and not going way off on a tangent, think of it as the same.
@@ajhartmanaero Not the same. Windtunnels don't give an 100% representation of pressure. They are only good for flow of air around a car.
@@Harty1275 I'm aware. Which is why I made mention of the wind tunnel not being a rolling floor, but the tunnels will make downforce in both situations.
Is it just me, or is that starting to look like the inlet of a NACA duct?
Bernoulli's principle isn't why aerodynamics work. Newton's third law of motion says that for every action, there is an equal and opposite reaction. Any aerodynamic force is the result of throwing air in the opposite direction. A splitter forces air to go upwards, which creates an equal and opposite force downwards. A diffuser forces mass of air upwards, which creates an equal and opposite force downwards. A wing throws air up or down due to angle of attack, which creates an equal and opposite reaction.
Bernoulli's principle only describes the airflow following the surface, not the forces experienced by the body.
While you are correct, it’s at a much much less degree than Bernoulli’s. If your theory was correct, then how does a diffusor make downforce on a car with a flat bottom work when there is zero airflow on the top side? Tunnels in a splitter are the same. There is zero air on the top surface to “throw” upwards.
@@ajhartmanaero The net effect is to push air upwards. We also like to think of air as flowing over a car, but the air is stationary and the car is moving. From the atmosphere's perspective, it is only moving up, down, left, or right to get out of the path of the car, and trying to return to stationary equilibrium afterwards.
If Bernoulli's principle is to be believed as a primary force, then any car is a giant airfoil which generates lift: air travels a shorter path under the car, while it must race a longer path over the body of the vehicle to rejoin, which is exactly like how an airplane would generate lift according to Bernoulli's principle.
You cannot generate motion without reaction mass, it is impossible according to our current understanding of science. If you propel air upwards, you experience an equal force downwards.
Does all of this new doo-hickies make my daily driver go faster during rush hour?
Who tf puts a splitter on the bumper? You need it to start at the bumper, and extend it towards the rear of the car. We're not talking ebay stick on splitters here...