In a couple of months the 2022 Formula 1 season will get underway with probably the largest single change to the aerodynamic regulations in its history. I couldn’t pass up the opportunity to do some aero investigations of my own, so today I want to share my concept of a 2022 car before the first real designs are unveiled.
1 – DESIGN:
Throughout this article I will refer to my design as “2022 F1 Study Car”; while it is heavily based on the F1 regulations it is not exact, and there are some things that are in-fact quite different. The bones of the car were based on the entry that I had put together for the 2020 MVRC competition on F1technical.net, borrowing the wheels, tires, suspension, and driver, and maintaining the same general dimensions (wheelbase = 3400 mm, track = ~1600 mm). With this in place I then created the aero reference volumes from the official 2022 F1 regulations. These reference volumes are boxes which define the general shape of the car; simply put, all of the bodywork must be contained within these regions.
In addition to these reference volumes, the F1 regulations contain a number of parameters which define the details of the surfaces (min / max radii, blending between parts, etc.). For simplicity I have mostly ignored these additional parameters and focused solely on the refence volumes. (This approach is probably most obvious on the front wing, where I have ignored the complex regulations regarding the blending of the wing elements with the endplate.)
Above: Reference volumes as defined in the 2022 regulations. It’s always interesting to see just how much of the layout of the car is pre-determined.
After creating an initial concept based on these constraints I set about running CFD iterations to tune the design. I won’t go into the details of the CFD but it is essentially the same OpenFOAM setup that I’ve used in previous posts. In total I’ve done about 150 simulations on this project, primarily focused on increasing downforce. As shown in Figure 1, I’ve been able to make substantial progress over the initial design. Most of these runs have been focused on the floor and diffuser, which is the biggest new area of the 2022 regulations.
Above: Figure 1 is a good example of what aerodynamic development actually looks like. In fact, future aero development can often be predicted from a chart like this with a reasonable degree of accuracy. Barring a regulation change or the rare breakthrough innovation it is difficult to achieve a step change in the aerodynamic development of a vehicle. This is why the performance of the 10 F1 teams tends to converge over time, and why F1 restricts development time to drive parity.
The geometry for the best (highest downforce) design is shown below:
Above: Geometry of the best (highest downforce) design that I tested. More details on specific design elements are given in Section 3.
Overall I’ve tried to keep this as a fairly conservative design. Given my simplistic interpretation of the rules I was hesitant to try anything too radical or stray too far from the concepts that have already been released by F1. I expect to see designs that are much more exotic than this on the real cars.
2 – GENERAL RESULTS:
The tables and figures below give a breakdown of the CFD results. Unless otherwise noted, all results are at a baseline ride height of 30 mm and 0 degrees rake. (For ease of notation frontal area is assumed to be 1 m^2 in all cases.)
I also did a basic sweep of rake angles, which is shown in Table 2. Most sources have been anticipating the 2022 regulations to render the high rake design obsolete, and these results seems to back up that hypothesis.
For reference I have also included the results from my simulation of the Williams FW43B, which was run with a very similar CFD setup:
These two sets of results are, of course, not really very comparable given that one was developed by an actual F1 team, and the other by a single engineer in his spare time. That being said, I would say that my 2022 study car is at least in the ballpark of similarity to the 2021, which is a good sign. (I would also say that, at least in my limited experience, it seems much easier to find downforce with the 2022 regulations than the previous ruleset. I have long suspected that the real 2022 cars will not see nearly as much of a performance drop as has been advertised.) The biggest physical difference between the two is the wheelbase, which is considerably shorter on the study car. I did an additional run where I morphed the body of the 2022 study car to match the wheelbase of the 2021 Williams, which gave the following:
As expected, the longer wheelbase (and thus larger plan view floor area) increased the downforce, from -3.679 to -3.820 CL. Such a significant change would of course have implications to the flow field of the entire car, and further gains could surely be realized through additional optimization with this wheelbase.
3 – DETAILED RESULTS:
In this section I have gone through some of the specific elements on the car and highlighted any interesting features or lessons learned during development.
I’ll start here because the floor is the part most different from a 2021 car, and because its characteristics drove design decisions in other areas of the 2022 study car.
The above image shows the design constraints for the floor profile. The top and bottom limits of the reference volume are in black, with the final floor profile in orange. The main parameters that I adjusted to develop this profile were the inlet height, throat height, throat fore/aft location, throat radius, outlet height, and outlet radius. In general downforce increased with lower inlet height, lower throat height, forward throat position, larger throat radius, and higher outlet height. The outlet radius was closely tied with the beam wing, which in-effect forms an extension to the diffuser.
The strakes at the front combine with the diffuser to roll up several large vortices and a key mechanism of downforce generation for the floor.
One key aspect of the 2022 study floor is the way in which it affects the balance of the car. Table 5 shows that while the overall downforce levels are similar, the 2022 floor design creates much more downforce at the rear of the car than the 2021. It was unclear to me exactly how much freedom the 2022 regulations give to the front of the floor and keel area and so I have again kept my design quite simple in this area. It may be that the real 2022 cars are able to generate more downforce at the front of the floor and avoid this particular issue.
The knock-on effect of the more rearward floor balance is that a greater downforce contribution is required from the front wing in order to balance the study car. The front wing volume is rather restrictive and I had to fill most of it in order to achieve the required balance. (Compare this to a 2021 front wing where the inner portion is cut away to feed air to the floor.)
As a comparison I did a run with the 2021 Williams front wing positioned on the study car, and another with the Williams front wing morphed to use the entire 2022 reference volume (see Table 6, below). With the wing positioned higher in the new regulations, even the morphed wing generated significantly less downforce than the 2022 study wing.
Front Wheel Vanes:
The front wheel vanes are not defined in the public part of the regulations, so I made a rough copy of what has been shown on the official F1 concept car. I’ve split the vane into two parts, the upper wheel fin, and the lower strake. The contributions of these parts are given in Table 7.
The chassis and nose are essentially the “default” design as given in the regulations and I have made no attempt to modify them. The sidepods were based on the current trend of high inlet and extreme downward slope, while the engine cover was made as narrow as possible, in order to feed air towards the diffuser. I have neglected cooling flow for this study, which may drive a very different sidepod solution on the real cars.
The rear wing profile was originally copied from the Williams geometry and then modified as needed to fit the study car.
Rear Wheel Vanes:
The public regulations contain very little information about the rear wheel vanes, so again I’ve created these based on images of the concept car. The earlier F1 wind tunnel model showed these vanes hanging lower than the diffuser, but they’ve been trimmed higher on the latest concept.
These vanes proved extremely sensitive to the design of the rear suspension and brake ducts, and in some cases actually reduced downforce. With an alternative suspension design (not shown here) the vanes eventually resulted in an increase of -0.085 CL and 0.058 CD. With this result the vanes were still causing regions of separated flow and clearly needed more refinement, thus they have been removed from the results of this study as presented above.
4 – CONCLUSION:
Ultimately the results presented in this study are unlikely to be very close to those of a real 2022 car. At best I may hope that some of the trends and concepts which have been discussed here are valid, and at worst they could be entirely backwards (the absolute numerical results are certainly not accurate). Nevertheless, I hope this study has given some insight into the aerodynamic environment of the 2022 F1 regulations and highlighted a few of the key items that engineers will have been working on over the past year. The first official car launch is scheduled for February 10th, and I can hardly wait to see it.
Thanks for reading,