The Art of Downforce: A Comprehensive Guide to Aerodynamics

In our previous episode, we covered the basics of aerodynamics and how drag and lift work together to create a high-performance vehicle. Today, we're going to dive deeper into the world of aerodynamics and explore some of the most fascinating techniques used by engineers to reduce drag and increase downforce.

Air Dams: Directing Air for Maximum Efficiency

One of the most effective ways to improve aerodynamics is by using air dams, which direct more air over the top of the car than underneath. This reduces drag and creates a smoother flow of air around the vehicle. By carefully designing the shape and size of the air dam, engineers can optimize airflow and minimize turbulence.

Vortex Generators: Taming Turbulence

Turbulence is a major problem for high-speed vehicles, as it can create drag and reduce downforce. Vortex generators are small devices that are placed in the stagnant area around the trailing edge of the roof, where air starts to separate. These tiny devices generate vortices off their tips, drawing the fast-moving air back into the boundary layer and keeping the airflow attached for longer.

Side Skirts: Reducing Lift and Increasing Downforce

One of the most ingenious applications of underbody aerodynamics is Jim Hall's Chaparral 2J race car. The Lexan side skirts were integrated with the suspension to maintain a constant one-inch clearance with the ground, even around turns or over bumps. This created a massive vacuum effect that produced up to 1.5 Gs of downforce, making it one of the fastest cars on the track.

Attached Flow and Separated Flow: Understanding the Boundary Layer

When air flows over the roof and rear window of a vehicle, it creates two types of flow: attached flow and separated flow. Attached flow is smooth and continuous, while separated flow peels off around the end of the roofline and disperses into the atmosphere. By placing vortex generators in the stagnant area where separated flow occurs, engineers can create a more stable and efficient airflow.

Aerodynamics in the Real World

The techniques we discussed earlier may seem complex and high-tech, but they're used in real-world vehicles like the Mitsubishi Evo and Civic Type-R. These cars showcase the importance of aerodynamics in reducing drag and increasing downforce, making them some of the fastest production cars on the market.

Conclusion

Aerodynamics is a fascinating field that requires a deep understanding of airflow, turbulence, and flow separation. By mastering these techniques, engineers can create high-performance vehicles that are both efficient and powerful. Whether you're an enthusiast or an engineer, understanding aerodynamics can help you appreciate the art and science behind high-speed driving.

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WEBVTTKind: captionsLanguage: enSideskirts! Diffusers! Vortex generators!Canards? This isaerodynamics part 2. Son ofaerodynamics!now that we've learned theaerodynamic basics of drag and lift and how splitters spoilers and wings work we can talk about when all those otherOther cool aero things are doing First just a quick review.Previously on science garage. we saw that drag is the force air exerts against the car as it moves.While the lift is the perpendicular force exerted by the air on the car. Today, We're mostly concerned with lift and it's better half.Downforce. Now about that air? DAAAYUM!Air dam. The air dam usually has a couple of jobs.It directs more air over the top of the car than underneath to reduce lift while alsodiverting air to the radiator to keep your car from overheating. In a sports car or a race car,the air dam is often designed to also shoot airdirectly into the intakeintercoolers or oil coolers.It might route air through some ducts and the brakes to help cool those off too.The air dam also cuts down on overall drag.Even on a boxy vehicle without it. The air would be tripped up by all the blocky shapes.You usually find hiding behind you that smooth bodywork on the front on the corners of a race carsair dam, you might find.Canards, which are also called dive planes or dive plates. I don't know about you, but the word canard makes me think of ducks.No, that's just me.Canards are usually flat wedge-shaped and angled upward toward the back of the car.They direct the air that moves around the side of the air damupwards which creates a teensy-weensy bit of downforce.It's not much because they're so small.But it's enough to help fine-tune the balance between downforce on the front tires and the rear tires.Canards can also be used to deflect air around the front tires because they can be a source of drag orthey can be used to direct more air up into the wings past at the back.Look if you want to get super serious about downforce,it's the stuff that isn't as obvious as a sick front fascia or a shopping cart wing that can make the biggest difference.Underneath your car. There's a whole lot of nooks and crannies and junk like brake lines and exhaust pipes.They're all meshing up the airflow adding a smooth undertray to cover up all that stuff goes a long way to reducingturbulence and drag it lets the air move below the car much more quickly and thatreduces the air pressure and can enhance the downforce but add a diffuser and now we're really making sausage.I mean downforce.A diffuser is typically a rear undertray shaped to make a gradually bigger space at the back of the car,but some racecars have front diffusers, too.It activates what's called a Venturi effect.Which is when a fluid speeds up as it flows through a moreconstricted area like the space under your car and remember Bernoulli's principle? That says a fast-moving fluid has lower pressure.Yup, that means even more downforce!as the space at the back of the car gradually increases in size thanks to the diffuser all the fast-movinglow-pressure air from underneath the car rushes up to fill that space this helps draw even more air across theunderside of your car when it gets to the expansion areait slows down and gains pressure with high pressure surrounding the car on allsides and a lot less pressure underneath an overallvacuum effect occurs and it sucks the car down to the road!Now that slowed down air can smoothly join back up with the slower higher pressure airflowing all around the car thisgentle reunionreduces drag at the fact which results in even more downforce!Keeping the air flowing effortlessly without turbulence is what makes all of this work.So wellSo vertical dividers called strakes are placed in the diffuser to help keep the air orderly as we learned in our first arrow video,downforce and splitters and wings usually come at the expense of a lot more drag but adding a smooth undertray and a well-designeda diffuser can reduce drag so togetherthey're one of the most important ways to increase downforce.Like Nolen without a glass of milk one without the other won't produce the desired effect.All right.We've created an area of higher pressure all around the top of the car and an area of really low pressure underneath.We're good to go right?Wait! Now all that high-pressure air wants to rush into the low-pressure area and that is exactlywhat we don't want and that is what side skirts are for the ideal side skirts extend as close to the ground as possibleto block that high-pressure air from sneaking back under the car and around the sides.That would increase lift and ruin the downforce that we just worked so hard to create. One of the most ingeniousapplications of underbody aerodynamics was Jim Hall'sChaparral 2J race car. The can-am series had just banned tall wings and moving aero devices for the1970 season so Aero pioneer Halldeveloped some creative workarounds for his new cars Lexan side skirts wereintegrated with the suspension tomaintain a constant one-inch clearance with the ground even around turns or over bumps and it's big!Boxy Booty were two big fans.Written by their own two-stroke 2 cylinder engine!The fans constantly pulled air through the underbody of the car creating so much of a vacuum thatthe 2J produced up to one and a half G's of downforce!But since the chaparral 2J fans moved air independently of the car speed, it produced about the same amount of downforce at low speeds as it did his high speeds.This meant it could do lap times a full two seconds faster than the next fastest cars.Competitors really didn't like that nor did they like all the dust and rocks the fans threw in their faces.This car was banned after just one season last but not least are those little vortex generators and we're gonna talk about it.In Mitsubishi Evo in Civic Type-R, not f1 turns because let's be honest!You're not driving F1So even though you can't see the air we know,pushing a car through it still causes some friction because it's got drag.Some air molecules get stuck near the surface and what's called the boundary layer.Meanwhile, the faster-flowing air tries to follow the curved shape of the roof and rear window and what's called an attached flow.It would be perfect for the Evo and the Type R if the air smoothly and non Drag Olli.Followed the window down then float across the rear wing where it would generate downforcejust like it's supposed to but is that what happens? No!Instead, the attached flow peels off right around the end of the roofline and becomes a separated flow,dispersing off into the atmosphere where you can even using that's whyraindrops don't always blow off your back window when you're cruising down the freeway. There's just a swirling massive turbulenceAnd that's not gonna make any downforce when it gets to the wing!However, if four text generators are placed in the stagnant area around the trailing edge of the roof where the air starts to separate there.Yes!Generate vortices off of their tips and that helps draw the fast-moving air down into the boundary layerwhich keeps the airflowattached for longer so vortex generators are there on the Evo and Type-R to make sure airpasses over the rear wing andgenerates downforce!Aerodynamics thanks to Skillshare for sponsoring this episode,Skillshare is an online learning community with thousands of classes and design, business,technology and more. You want to impress your friends?We'll take the basics of Photoshop by Meg Louis. Premium Membership gives you unlimited access to high-qualityclasses on must-know topics so you can improve your skills,unlock new opportunities and do the work that you love. Well, what I did? I fixed my complexionLook how smart I look, Skillshare is also more affordable than most other learning platforms out there, an annual subscriptionis less than ten dollars a month the first500 people to sign up with the link in the description will get the first two months for free. That's 20 bucksSo go to SKL.SH/SCIENCEGARAGE3 or click on the link in the descriptionSkillshare!Subscribe to donut. More people who subscribe, the more cool stuff we get to do for you. Follow us on Instagramand Twitter at donut media. You follow me at This Bardo. Talk about Civic Type-R,you can check out the new car show where James drives one around. You guys want to see the blockbuster episode that started it all!Check out Arrow part 1. Don't tell my wife that I'm keeping the olds.