now that we've covered the basics in pressure and flow let's dig into the more f1 relevant parts of aerodynamics how to control or wild and unwieldy air flow let's jump straight back to where we left off in the last video then looking at our side profile of a wing with all the air flowing around it so neat it isn't always so neat though and we'll get to that but first of all let's quickly work out why the air underneath the wing follows the surface at all you see if you imagine these layers of air rushing towards the wing or straight like this the natural tendency for this air is to keep going in the direction it was the underneath air will keep going straight and this deflected air will keep going down though the fast-moving under layers of air should absorb this so why does it in reality follow the surface of the wing because if there's no or very little air here then it means this is a very low pressure area and as we discussed previously high pressure air will flow into areas of low pressure so all this high pressure high-energy air is naturally going to bend into this pocket hi I'm just gonna stop the video here for a second and make a clarification on the last video in that video I said that the air under the wing moved faster because it was being accelerated by being squeezed that's not the whole truth and the majority of the acceleration actually comes from the air being pulled into that low-pressure area so sorry if I misrepresented what was happening there okay back to the video there's a second smaller effect going on here too and that's the friction between each layer of air it begins right at the surface of the wing where the first layer of air particles actually doesn't really move at all because it's stuck to the wing by molecular forces each layer of air is attracted to each other between the basic static layer there and the fullspeed layer over here each layer is moving a little bit faster due to the friction between each individual layer of air this section is called the boundary layer the amount of attraction or friction between layers of flow is called viscosity the viscosity is one component of overall aerodynamic drag because the surface of the wing or car is tugging on the airflow slowing it down which means that in turn the airflow is hugging on the surface slowing it down right so we now know why air flow follows the form of a surface now I'm going to show you when it doesn't last video I tip the wing up like this increasing its angle of attack and all the air followed it diligently this will give you more downforce I said but I tipping the wing up this high may well ruin everything and give you even less downforce you see if air is going fast enough the momentum of the air may overpower the pole of the low-pressure area here and instead the air will mostly just plow on being deflected only slightly towards the wing this is called air flow separation or detachment it should be clear that with the air flow separated the average direction of the air flow after passing around the wings is less upward and if it all stayed together this means that a separated airflow gives you less downforce than an attached airflow between these two flows of air the air in between doesn't really know what to do with itself the boundary layer will get sucked away from the surface and then get all garbled trying to resolve the pressure differences this is called turbulence and you may hear it referred to as turbulent flow with the nice smooth airflow being called laminar flow laminar just meaning layered right around the point where the airflow separates the amount of downforce the wing delivers will drop massively though the drag continues to increase this is called a stall so how do we resolve the problem of separated air flows ruining our nice efficient downforce well we could just not tilt the wing so aggressively but that's giving up we need to find a way to keep this fast flowing energetic air attached to the surface for longer and the answer is vortices a vortex is just a spiral of air spinning like a screw along the airflow so if we can imagine getting a vortex of air to flow between the attached boundary layer and high energy separated airflow you can see how it could start bringing them together pulling the high energy detached air into the boundary layer and allowing it to stay attached for longer while smoothing out the disturbance between the boundary layer and the separated flow so in short a vortex can help keep air flow attached to the surface it's flowing around this doesn't just apply to the wing but applies to the entire chassis to consider the car as a whole we've got a number of places we want high energy fast flowing air to go the air intakes and the huge down force generating rear wing for example but before the air can get to those places it has to navigate the body of the car and we don't want a separation and airflow to accidentally send a bunch of weak turbulent air into the rear wing or into the air intakes instead we can use vortex generators to keep the airflow attached to the see and minimize the turbulent low energy flow a further downside to air separation is that it causes drag imagine the car pushing through the fast flowing air if the air separated dramatically behind it this leaves a huge hole in the air of the cars wake a massive low-pressure area behind the car now with a high pressure area in front of the car and a low pressure area behind it this causes a net force to act backwards on the car dragging it back reducing its speed you can also think of the low-pressure area creating a suction if that's easier it's the same thing if maybe slightly more clumsy way of putting it generating some vortices helps to attach scattered air flows to the body surfaces and reduces turbulence in the cars wake which will reduce drag on the car and I've been showing you a car side on but this works in all dimensions a lot of work is put into keeping the air attached right along the side of the car to to stop the air doing this and to make sure it does this if at one of the major jobs of the front wing and the reason it always looks so complex is to build huge vortices to help the air flow down the side of the car and to stop it getting mucked up by the mayhem course of the air by the spinning tires all of the details are intricately sculpted tips of a front wing are designed in age of vortex generation that will help persuade the air and its flow all the way down the car if we can take just one element so look at it we can see how vortices are generated so above the wing we've got our high pressure air and below the wing we've got our low-pressure air now as we know the high pressure air will try and flow into the low-pressure air to resolve the difference and it doesn't have to wait until after the air has passed over the wing to do it at the edge of the wing here the top flowing air will try and curl over the wing and get to the bottom flowing low-pressure air from here we can see how a corkscrew movement starts at the wingtip and will continue down the chassis all of these wingtip shapes will work together to create really huge vortex that doesn't just help keep the good air flow follow the shape of this chassis it also helps keep the bad airflow the disturbed turbulent air in the wake of the spinning tires away from the bodywork to stop it ruining everything these vortices are the bounces of an f1 car telling the drunk tire airflow to keep on moving so keep on moving so that's the basics of how you control airflow and coax it into it doing exactly what you want it to do the next video will be a bit for free for all on little arrow bits like what does this thing do why there holes here what's a barge board that kind of thing thanks for watching this video is quite short and cheerful but I really wanted to get into the heart of what fault disease whereas they're discussed so much in our dynamic chat next week I probably do the last part of this sort arithmetic series but continue to do videos at touch on aerodynamics in future thanks so much to have on and continued series of what we're doing these videos I've managed to not have to leave makes a big gap Cheers great and the next video in this series should be out next week [Music]