How F1's 2021 ground effect differs from its fearsome predecessor - Chain Bear explains

in July Formula One released so-called blueprints for 2021 the latest in a long line of teasers and updates about the long-awaited revamp in the technical regulations while the blueprints more a showcase of principles and design philosophies than anything too specific covered a breath of thinking on where this new era would take us I wanted to focus on a specific aspect of the regulations that's finally been confirmed the return to ground effect focused aerodynamics ground effect have been speculated on and argued for as a means to solving a lot of air phones modern aerodynamic problems that the complex over body arrow was causing chaos to the air behind each car and providing an invisible barrier to cars in pursuit simply the air flow behind an f1 car is so turbulent and violently disrupted that the aerodynamics of the car behind is simply stopped functioning properly with current cars losing almost half their downforce when just two car lengths behind another ground effect is nothing new it had a pretty short-lived but intense haida in Formula One from the late 70s to the early 80s until it was banned outright on safety grounds almost all of the restrictions on the underbody of the car including the need for a plank the diffuser regulations and the incredibly strict floor heights and dimensions developed as extensions of the banning of any attempts to over exploit the ground effect so let's take a step back what is ground effect and what did it look like originally and why was it bad in the first place back in 1977 wings and over body arrow were already being put to good use in generating downforce for the cars manipulating the airflow over the cars to push them into the ground increasing their overall grip but this downforce came with baggage drag if you stick a big wing on the back of your car it also has a parachute-like effect acting as a big air brake by blocking the fast airflow over the car reducing maximum speed finding a nice trade off between down fossil or lift and drag has always been part of the engineering problem since wings are invented however Lotus realized you could generate downforce in a different way a way that doesn't disrupt the airflow half as much as a big old wing sticking out of your car and that's by exploiting the venturi effect underneath the car the venturi effect is a pretty simple phenomenon exhibited by fluids air also being a type of fluid if you imagine air molecules flowing through a pipe the rate of molecules flowing through the opening the pipe has to be the same as the rate of molecules leaving the pipe if ten molecules a second enter the pipe and any five molecules per second leave the pipe it would all clogged up but that doesn't happen the molecules here will force the rest out to match their rate okay but imagine we squeeze the pipe in the middle now we still have to have the molecules moving at the same rate but now there's less room for them so they have to physically speed up to fit through the restricted or choked section so what we have is an area of faster moving air in the middle here and that comes with a big drop in air pressure and if you lower the air pressure you create a suction effect so instead of a pipe if we just shape the underbody of our car in such a way that air flow goes through a choke point will create a big area of low pressure right at that point and the low pressure will suck the car towards the ground and that's exactly the same effect as downforce you've manipulated the energy of the airflow to pull the car towards the ground and also because the defuser works to gently return the accelerated air back to its free stream velocity you can do all this without completely throwing the area to complete chaos behind you in the way that wings and body work do a key to maximizing the effectiveness of these venturi tunnels under the car was sticking skirts on the car essentially just a strip of bodywork that sealed off the edge of the floor as close to the ground as possible so the majority of the air was forced through your venturi tunnels and wouldn't escape out the sides at the floor so sounds amazing right and it was Lotus started a development race that got everybody focusing on the underside of their car and cornering speeds climbed rapidly rising cornering speeds will always catch the eye of the FIA as this starts to become a huge risk factor the downforce was heavily reliant on the skirts working properly and if they broke or if the car bounced heavily over a bump lifting the skirt away from the track and the cars could very suddenly lose a lot of downforce being half way around a high speed corner only to lose masses of downforce unexpectedly puts you in an incredibly dangerous position especially back in the early 80s before serious overhauls and track and car safety took place through subsequent decades so skirts were banned and cars floors were raised and then the entire floor of the car was mandated to be flat essentially removing all venturi tunnels under the car though diffusers were allowed to manage escape of the airflow under the car nowadays cars have a stepped floor with a minimum height reference plane where the plank sits and a step plane 50 millimeters above that this reduces the ability to create low pressure flow under the car okay so let's look forward to 2021 then if ground effect is so dangerous it's been enthusiastically banned for three and a half decades then why allow it back well there are a few reasons for one the cars on the track are a lot safer now and we can have more control over cornering speeds through other means should we need to secondly the over body arrow is is so exaggerated now that a new means that generating the high downforce and awesome cornering speeds the f1 is all about has had to come from some rethinking of old ideas thirdly we're not going all the way back to the 80s style skirts mega ground-effect cars instead the India prototype model exhibited in the most current blueprints meets the mone some of the way the first thing we're not bringing back the unreliable skirts as we knew them in the current proposal we're going to do something else which I'll explain in a moment the new floor is now going to look something like this the old tea-tray squared off plane will now be allowed to taper and allow air to flow through these venturi tunnels that flow the length of the side pods and back to the diffuser the air will be managed into these tunnels by reappropriation turning vanes to maximize the efficiency of the flow everything will flow into a deeper taller diffuser that will be able to manage the transition between this fast flowing air and the free air behind the car now in place of skirts we have these long veins running the length of the diffuser that helps seal the airflow from the floor through the diffuser but instead of being mounted to the car body they appear to be extensions of the rear brake duct structure and thus will maintain a height consistent with the tire not the chassis this by extension means there'll be more reliably level with the ground even as the chassis travels through the suspension so as we move the downforce generation to the under body we see a lot of error effects being taken away from other parts of the car the rear wing now is stylish and simplified without strict end plates which reduces its downforce as well as its wake we have this lower element to the rear wing here that extends the effect of the diffuser and the underbody flow the front wing to continues to be simplified and joining it to the nose all but takes away the huge y 250 forte the team's fight to generate that currently produces a heap of turbulent outwash the small veins cradling the front wheels as well as the return of wheel covers will work to smooth the airflow on route to the turning veins an underbody and if this works as developments in the CFD model continue we could see an entirely new philosophy of car development from 2020 one and as DRS looks increasingly likely to be eliminated in these designs there seems to be a growing confidence that closer racing will soon return you

Channel: Autosport

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Keywords: F1, Formula 1, Formula one, F1 2021 rules, F1 future cars, F1 tech, Chain Bear, F1 ground effect, How does ground effect work, Why is F1 going back to ground effect?, F1 ground effect 1980s, F1 ground effect Lotus, Is ground effect dangerous for F1?, Autosport, F1 news

Id: dlNmWJLyylM

Length: 7min 34sec (454 seconds)

Published: Thu Aug 01 2019