Red Bull RB17 - Aerodynamics Analysis and Initial Thoughts

Red Bull just released the RB 17 in this video we're going to go from the front to the back of the car having a look at how the aerodynamics work on this particular car for those of you that are new to my channel I was an aerodynamicist for Mercedes for the 2018 19 and 20 Formula 1 seasons and I now work as an aerodynamics consultant designing race cars in all different classes all around the world now there's already an interview with Adrien about the car in general however in that video he doesn't go super into the aerody dnamic so we're going to look here a bit more at the specifics of how each a devices functioning on the car firstly let's talk about the downforce numbers on this car now they've claimed 1,700 kilos at 240 km/ hour now this equates to an scz of about 6.1 is the more interesting number is the efficiency that's been claimed that's a a claimed efficiency of 16 to1 which puts the scx around about the 38 Mark now given this is a 12200 horsepower car of which I think about 200 horsepower is electric let's say that we're putting 800 kW to the wheels roughly that would give you a top speed in excess of 540 kmph however the car is limited at 350 case per hour because of uh limitations of the tire loading to mitigate some of those the car has active Arrow we're talking active rear wing active diffuser and active front Wing that can back off with speed so that downforce will bleed off at speed although there's still going to be a significant component of downforce on the tires increasing that tire load meaning that you have to limit that top speed now in addition to the active area there's also active suspension for platform control and there's also been mention of some fans being used for active Arrow there I'll go into the fans a little bit later with some speculation what's interesting to me is that with a 900 kg car and these downforce numbers they are claiming that this car can lap similar to a modern F1 car now that's with considerably less downforce to weight than a modern F1 car yes it's got better efficiency but the power weight's not that much higher the top speed is not that different so in terms of where they're generating their extra lap time from I'm not exactly sure some of it might be the characteristic with obviously the active suspension uh plus the the blowing uh but the other thing that may be happening is these numbers that we've been presented with may be revised as the final version comes out because this current version is an earlier development model that we're seeing so we're not quite sure if the spec they're giving us now is what it's actually going to be to finish up it's worth noting too as we'll go through in the flow analysis there are a fair few number of styling features on this car Adrian talks about in his interview the fact that there are styling details and aesthetic details on this car and so it's worth noting that there will potentially be some minor Arrow hits here and there for styling compromises so anyway let's go into the arrow analysis part of the video and that comes with my usual disclaimer of no a dynamist can predict flows perfectly by eye you need cfd and wind tunnel Etc to try and work them out exactly but I'll still give my best educated guesses as to what's going on aerodynamically I think of this car as an evolution of the valkyrie it runs on very much the same sort of General concept as that car you've got essentially a multi-element front Wing floating around in free air with a large volume of open space behind it you got a relatively High degree of paracity up high and then you have an outwash element behind a largely exposed front tire the floor then has two large entry tunnels that then go back into a big three-dimensional diffuser at the rear that has a lot of flow going in Board of the tire over the body work so that it goes in between that diffuser and the rear wheel you then have a lowline low set rear wing that has in this case the the same sort of end plates that wrap around that are similar to something like the valkyrie AMR Pro but of course there's been quite a few critical detail changes so let's roll through this car as if it was largely a new car so starting at the front Wing one of the first interesting details I want to just point out is this Central support you'll notice that it's only got a single support as opposed to a more traditional layout which typically has two supports now the reason why you typically have two supports on a wing like this is is that during something like a a rolling condition or something like that what will end up happening is that this side of the wing will be lower to the ground than this side of the wing and so you'll often end up with more suction in this area now when you have more suction there that will increase the down force on this side of the wing you'll get an asymmetric loading of the wing and so you have two supports to try and cancel out that loading because a single support would be much harder to get the structural stiffness however this is a fully bodied car so what it means is that you've got a whole bunch of support coming out this way in terms of this box over here that's also tied back over here into these wheel pods and when you combine that with this little stay that ties into the end plate you'll see that that allows you to increase the stiffness of this region in asymmetric supports and then just carry out the main vertical load through that center pillar now why would you go to all this effort well having just one pillar in the center means that you have less losses go Downstream and enter your floor if you have two pillars you're getting losses off each of these pillars and they're going to go and find their way into the entry of your nice little floor tunnels one Central pillar means that you've got less loss overall and it also means that loss is more constrained to the dead center line which given this car's tunnel layout might be a little bit less sensitive to it it's not going to be a huge gain or anything like that but it is perhaps a subtle Improvement now aerodynamically what we have going on here is we have a wheel blocker that goes fully in front of the front wheel then we have a flat area directly in front of here you'll not it's not up washing or anything like that we have a small curled foot plate to the outside and then we've got further in board our cone region so that's our cone there and then we have a wing profile that just goes through the center no y250 no Vortex generating features anything like that it's just clean and up washing through the center there's also a single Delta end plate on each side so let's go through each one of those features now the purpose of the wheel blocker is obvious enough it is to stop a large amount of high energy air impacting the The Fairly square and fairly flat face on the front of your tire if you have this air impact you get a high stagnation pressure on the front of the tire and this causes a lot of drag but you also increase the energy going down into the contact patch which will increase your tire squirt so you want to block off the front of the tire but you'll note that on both this and the valkyrie the blocker is significantly narrower than the tire now this is likely because if the tire is rotated in steer this inside wheel face will come into line with this Edge we don't want to have a situation where we steer the tire and this Inside Edge is overlapping the tire too much because then we're just losing energy to the inside of the tire we're blocking off more air flow than we need to so that's why this is smaller than the front of the tire because it's got this vshape too where where it's basically you obviously got a filtered corner but it's still out washing to the end more or less it's still going to direct the air around that tire so you can pick it up around the shoulder and then uh on the inboard side they can pick it up with the cake tin face and the valkyrie nobly had a small little deflector on the bottom of its cake tin down here so they can pick up that flow that's coming across there and use that to manage the tire wake further Downstream now we then have this flat section in front of the tire now often up washing in front of the tire can be problematic for the same reasons that I discussed previously you wouldn't do it if you didn't need the load uh on the car in there and they've got this big double elements section over here so they can get as much load as they feel like through there so they've gone flat here which I'm going to guess is going to improve the overall effective down wash into the contact patch versus a cranked version which should improve again any sort of Tire squirt it will also generate quite a lot of local load on it due to the low ground proximity because this cranked cone section over here is going to be generating a lot of inh there'll be flow coming in across that way as we go along so obviously the flow is coming along but it's also moving with a sideways component as it goes into the cone Vortex over here and so you'll get a decent amount of suction on this flat pain as well even though it's not upwash itself this of course will cause a bulk mass flow to come around the wing around the edge of the wing like we see on all wings and so these two outboard features are there to manage that so you basically have the end plate which is going to stop a lot of the the mass flow going over so you'll keep the high pressure on the top surface you won't let as much mass flow be bleed around so you'll depower the bottom surface a bit which can be important in terms of keeping the health and cleanliness of the lower surface and you'll note that this particular plate has quite a bit of camber to it it's cambering that way and that's going to help with the acceptance of the flows that being pushed laterally outward on the upper surface now the end plate is a Delta shape I'm not sure that this is the optimum shape that you go for Adrian obviously spoke a little bit about how some of the features of this car are styling features I'm not saying that the end plate shape is a problem it's more I'm wondering if they've made it Delta shaped at at no real aerody Delta in order to visually make it look a bit better perhaps visually tie it into a modern F1 car lower down this little foot plate curl will have a little Vortex down here now in terms of the direction Downstream uh it's a little bit tricky with these because depending on the inboard interactions they can go in some pretty weird locations but I'm going to guess that it's probably going to be crashing into the front of the tire uh but depending on everything else that's going on around here it might go much further in board or in some conditions I have seen these actually stay outboard of the front tire um so no idea where that's actually going uh but having this curled should be a lot cleaner and house the vortex in a more consistent manner than just having it flat so like I mentioned before this cone here will create a large vortex that will go Downstream the trajectory of this Downstream will depend massively on the pressure field being generated by the devices behind it but there's there's two potential rots they could essentially go with this vorticity either they could go and they could try ingesting it in the tunnel back here and that would sort of uh stack with respect to the rest of the tunnel shape because they've clearly got a very large tunnel Inlet it's already ConEd and shaped in a circular manner it would make sense if they were ingesting this foric in there and using it to boost the strength of the entire tunnel that would stack um another option is that it could be getting outwash behind the tire in sort of cavity there but I'm not convinced that that's as likely given there doesn't seem to be as many things that would be outw washing enough far enough uh in board in order to to trigger that particular trajectory now this Vortex as it goes further rearwards will create uh a bunch of down wash alongside the side of the tire it will get down washing but it will also generate a lot of inh so you can harness this down wash to to improve uh some of your mass flow towards the side of the tire which can help a bit with lower wake management but right down at the bottom around the tie squirt and stuff like that it can be quite negative as well so that may have been managed by another device on the kin that we haven't been able to see yet uh but that's the general gist of what's going on there moving a little further Downstream you can obviously see those stays and those front Wing details that I was talking about earlier but I just want to take a quick second to highlight its wheel discs now these could very well changed model to model as has been mentioned before this car is not the final version it's just a static show model uh but these particular discs uh with a thin Outlet around the outside that allow mass flow to come out there could help with reducing the the spoke drag reducing the ejection of loss from the wheel and that could help with this car's overall efficiency Target because like we discussed earlier this is a very high efficiency car so it would be important to try and improve the efficiency where possible through devices like this which are closer to a flat-faced wheel looking a bit further rearwards I want to focus on the upper body work for a little bit now you'll note that we have this bridging element out here uh after we have this large gap and these elements bridging front and rear obviously are there to help connect this wheel pod here but you'll notice that this whole section here basically transitions further rearwards into this down washing side pod here now this is not dissimilar to the setup that you'll see on current F1 cars where they basically use the the top deck flows and then Channel them towards the floor at the rear now it's divided a little bit in the center by the rearwards bridging element that's holding on the rear pod there but you can see the general intent is to try and get everything down to the floor and the rear diffuser you actually have a clear sight line on it and the transitions are all pretty smooth even both below and above that wheel fin looking a bit lower down you can see the large barge board just inside of the front wheel now as has been discussed a few times this sort of feature is designed to create a large amount of outwash and basically kick the the front tire wake they'll be sitting all here try and kick that as outboard as possible um to basically try and get it clear of anything that's going to be coming along the side of the car we don't want to ingest this wake further Downstream we want clean air to everything else and ideally all the air that's to the inboard side of this particular fin we want to have that going Downstream and feeding everything rearwards feeding everything out the side of the floor and stuff like that we don't want to be ingesting low energy Tire Wake into there again if you look further rearwards you'll find uh this particular end plating shape on the rear the rear wheel pod is quite Valkyrie like but this end plate is a little bit different again I'm not sure whether or not this is a a a styling inspired feature or whether this is pure Arrow if I had to take a guess I'd say that this is a styling feature again I wouldn't expect a large Arrow Delta on it but it's just worth noting that this is unlikely to be what youd pick if you just wanted a raw performance rear end and why do I say that well the the overlaps are all a little bit strange in terms of having a Delta that crosses over at that particular point it's just not something that you would normally go for aerodynamically let's say you wanted it to be uh slatted or you wanted to create a jet of air around there you would normally align your leading edges so that everything would fix up and you you'd make a second element like that you wouldn't normally go for this delta type shape looking a bit further in board you can see a few features of interest uh one is this little bulge here which I think is going to be the air intake for the cooling system it's likely that this thing is going to have an F1 style radiator or similar in this particular region here and then just a little bit further down you'll see just how high that floor Leading Edge is that's the entrance to the tunnel there and it's really really tall and let's go a little bit further rearward so we can look a bit at this diffuser from the rearwards portion of the car where you can really see what's going on there now the diffuser on this car is somewhat expectedly massive uh it has a very similar visual to the valkyrie because it's similar sort of size but there's quite a few differences in here that I think are worth noting firstly looking at the inlet what you'll notice is that it has a uh a curvature that goes with a narrower front down low that then outwash there now that's a little bit different to the valkyrie which went the other way uh I'd guess that this is largely to increase the loading uh on the forwards portion of the diffuser get that suction in the forwards portion of the diffuser and power up any sort of ticity that's coming off here now what's interesting is that you can actually see the front Wing cone that I was describing earlier so if they are in fact shedding that cone vorticity into this tunnel well you can at least see where that's coming from the diffuser doesn't gain much in height over the the forward portion anything like that it's worth noting that Adrien talks about in an interview about how forwards loaded this diffuser is so let's work out where the forward load is coming from obviously we've got some of that out more outwash and front that we were talking about earlier but then also if you have a look this diffuser has a lot of lateral expansion as it gets further rearwards basically the core where the driver is sitting and the passenger that tightens up a lot towards the rear and this lateral expansion will essentially increase the volume of the diffuser going rearwards even though the roof isn't expand standing that much and this will create suction in the mid and forwards portion of the diffuser as well as the fact that if again we are taking vorticity from the front cone that vorticity will be more powerful the further forwards it is so that will inherently lead to a more forwards loaded defuser now this diffuser volume is more or less limited by the axle height of the car cuz if you imagine the lower Wishbone is at the line of the axle so it's all the way up and then the diffuser sits below that point there so that's more or less limiting the height however once you get rearwards of that point rearwards of that rear axle you can then start to expand and this diffuser starts to expand very aggressively in all directions at this point to support that expansion to that end what it's got is this triple element setup which I think is quite neat so what you've got is is that you've got your first element here so that's your your first split um and if you imagine that's like the the whole diffuser of the first element then you got your second element here that's your next split and then you've got the third element just behind it there and these elements are expanding in all directions uh so basically maximizing your expansion there as discussed before we have a lot of clean air flow over the top of this diffuser so every time you have a slot here you're bleeding in clean air flow and you're allowing it to work like a multi-element wing expanding out aggressively through this whole portion the first split is quite low the second split is much higher uh and you'll see it comes further in board over the top so the the first one seems to be just largely for the lateral expansion just cleaning up any any Flows In This lateral expansion bit for the first portion then the second one we're getting essentially a beam wi type effect by splitting it here and then expanding upwards uh as well as laterally so I imagine this would allow quite a lot of diffuser expansion quite a clean way and if you have a look uh this is expanding out behind the rear of the tire and so that's going to push the tire wake outwards as well pressurize this whole area and that's going to suppress the tire wake it's basically like a much larger version of the sort of winglets we saw on the back of F1 cars uh in the previous generation of rules in the center you'll spot there's a single thin on the Keel and this is an interesting one to ponder why it's there because if you consider a car just symmetrically in a steady state in a straight line there's no real intent or purpose to devices dead along the center line however cornering and driving a car and a track is a little bit more complex than that so let's run through some potential scenarios where this K could be useful the first one I'm just going to put uh out there is a scenario where you have a large amount of Y um across the car and you've got a large crosswind going across the car basically that will push the airflow in towards the Keel and the Keel will act to an extent like a shark fin that I think is a fairly minor contribution compared to what I think one of the bigger things that will happen in your is that you'll have migration of your big tunnel vortices one tunnel Vortex will end up moving towards the Keel the other one will move away now having the Keel there will reduce this particular migration and keep each Vortex on its side a little bit more which may be a more Optimum position given the overall uh annular shape of this tunnel I would H to Guess that it's quite reliant on the vortices being in the right spot so that could be a potential thing there another thing to just discuss briefly is the concept of Vortex Meandering if you imagine vortices in the real world like to do a little bit of move rounds they sort of vibrate and sway all over the place kind of like a a wave this is called Vortex Meandering and again if you have a diffuser where the vortex positioning is critical perhaps adding this fin in the center would help with the Meandering now it's it's worth noting that to my understanding this car has only been done in cfd not in the wind tunnel cfd is not very good at Meandering so it's probably unlikely that this is the the particular scenario it's more likely it's the your scenario but it's just something I thought I'd throw out there anyway looking a bit higher up you'll see this triangle shaped portion now I think that this is likely to be where the cooling air is exiting out the back of the car judging by some of the diagrams it looks like the exhaust is going to exit a little bit further Upstream on the top even though we can't see that on the model it looked like it from some of the mechanical drawings but in the absence of seeing anywhere else for the cooling air to exit I'm going to Hazard to Guess that this is its exit right in the center while we're here too you can can also just see the brake Scoops up there uh and this is where the rear Brak is going to be getting all their cooling air from again because there's so much free air over the back of this car this car is essentially a single seater with a few pods strapped onto it it's easy to just run an F1 style brake scoop for your brake you don't have to worry about any complex ducting or hoses or anything like that moving a bit further upwards let's talk about the rear wing now the implementation of this is quite an interesting one because they've sort of combined it so that it aesthetically Blends the rear wing into the rear wheel archers all together so if you can imagine the rear wing is essentially a a sort of one and a half element Wing I'm going to call it where basically you have your first element is sort of integrated into the wheel arches here and it goes to sort of along here and then you have a second element that is this black portion that goes along the back just there and you have a look in the rear view here you can sort of see that first element go along there and the second element just above it now integrating the rear wi into the rear arches like this is quite a cool looking thing I think it's a fairly neat implementation from an Aesthetics perspective uh but it does bring about some aerodynamic peculiarities that we need to discuss uh the first one is that this particular portion just here around the wheels is a very interesting transition uh because you basically have to go to a Leading Edge on your wing here and then as you go around it here you have to work out exactly how you want to treat it do you want to try and lift it up to to try and get as clean as possible a flow there or do you instead want to manage it through a sort of Delta Edge uh and shed some sort of vorticity or structure along here that will keep it relatively attached in this corner region near the arch guard now looking at this geometry I think they're going more of that Delta approach getting that vorticity off the Leading Edge and using that uh to keep the wing somewhat clean through that later portion but it's certainly a more tricky Junction than if you were to go and have a fully Standalone Wing element the other thing that's worth noting here is that this Wing sweeps around into the arch which means that this portion through here directly behind the rear tire is going to be full of almost nothing but loss the the there's going to be some energy coming through the the wheel Arch and over the top but in general you've just got a lot of Tire Wake so actually the outboard portion of a lot of this particular Wing section in here is not going to be doing a whole lot of work but again the alternative is to just have a wheel Arch sitting there which also isn't doing doing a lot of work either so this may very well be a more efficient option in that particular region then obviously you have the 3D wraparound second element now this element is going to clean air the whole way around it's got a slot Gap across this this Bodywork the whole way around there so this is going to be quite a potent element it's getting clean flow it's in good air it's going to have good communication between the suction it generates and the diffuser so it's going to drive the diffuser well it goes the full width of the car and it's outw washing laterally at the ends so we're getting that real 3D expansion going on there and it continues the whole way to the ground so they're obviously using this lower portion to manage this rear wheel wake and kick that rear wheel wake further outboard and all of this is going to generate quite a solid amount of performance and that ties in to the very high efficiency that we spoke about earlier in the video one thing that's worth noting though and I think this is a detail that's probably going to change on the final version is this particular Center Line section here in the forwards portion what you'll see is that it's got a very large expansion ratio basically this whole Leading Edge stays flat across the front and that means that when you have this down washing Central deck through here you have a small area right along the center line and then it becomes very much larger by the time you're getting towards the rear here so there's the likelihood of having a separation or Junction losses or overexpansion or anything here is pretty high I wouldn't be surprised at all if on the final version they have a curved Leading Edge that comes up a little bit more in the center to try and get better acceptance from the down wash from the the center line of the car uh and trying to to deal with that Junction a little bit better so a final note on something that I mentioned at the start of the video which was the fans now Adrian mentioned in an interview that they're going to be using fans and not in a manner that has previously really been used now to my mind that makes me think that what he's likely doing is probably going to be going for a blowing action that's going to go and suppress the rear tire squirt whether that's located outside or inside the diffuser but potentially using fans to blow and suppress that tire squirt and thus improve the performance of the diffuser and one of the reasons why that comes to mind is is because this is obviously something that Red Bull was known for uh back in the blown diffuser era uh and you'd basically just be replicating the blown diffuser effects but with fans which would be a far more energy efficient means uh than just trying to suck out from this Giant volume of diffuser because the problem is this diffuser is extremely large volume which meant that if you just tried to suck out of it proportionately you probably wouldn't be making that much of a dent because it's not like it goes down to a flat floor or anything further forwards the only other way you could potentially use fans is to just have them suck out from along the center line which is the one bit of the car that is actually a large flat area down low so if they're not doing that the only thing that I could be thinking of is they're going to use the fans to try and do some sort of blowing effect of course that's all a large bit of speculation but it was the best that I could come up with well that's all for this analysis thanks for watching if you liked it don't forget to hit that like button and subscribe to my channel for more content like this leave a comment below what videos you like to see next from me and hopefully I'll see you next time

Channel: KYLE.ENGINEERS

Views: 31,076

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Id: JocsHmRnFKU

Length: 26min 51sec (1611 seconds)

Published: Sun Jul 14 2024