With the change of rules in 2022, the wind breaker board will no longer appear on F1 cars, and the 2021 season with the change of the bottom plate rules, the downforce is 15%-20% lower than in 2020, but it has not yet seen all the speed of F1 cars reduced, or even faster, one of the reasons is the contribution of the wind breaker board, the design of the wind breaker board of the 2021 season of F1 cars is becoming more and more complicated, but how do they work?
<h1 class="pgc-h-arrow-right" data-track="2" > the origin of the wind breaker</h1>
The origins of the windbreaker can be traced back to the 1985 season, when both the Lotus 97T and McLaren MP4/2B race cars were equipped with similar kits on the back of the front tires. At that time, the F1 car was 2.15 meters wide and the body width was only 1.4 meters, while the F1 car has maintained a width of 2 meters since 2017, the body width of the car is 1.6 meters, and the wider car means that the spoiler formed around the front tires is more sensitive than ever. The previous F1 car front tires were also smaller, and the spoiler around the car was not as clear and easy to control as it is now.
In 2010, Bruno Senna test-drove the Lotus 97T
In the 80s, the wind breaker board did not really catch on, and only the Lotus 98T continued to be used, but the 99T was also discarded. However, tire wake management air power kits were copied from the late 80s to early 90s by the ubiquitous front wing end plates and extension foot plates, which helped capture the "tire wake" and spread it outward or away from the baseplate. After the 1994 Imola Tragedy (Senna Crash) race weekend, a no-go zone was added around the front tire to ban the air-powered kit laying in the area, and the windbreaker was reintroduced later in the season, particularly on the Williams FW16B.
1993 Williams FW15C extended front wing end plates and foot plates
The mid-90s to early 2000s versions of the windbreaker are available in two genres:
Use small blades placed under the front suspension, with their trailing edge as close as possible to the inside of the front tire as the rules allow.
High blades located at the rear of the front wheels and in front of the side suspension, but with their leading edges closer to the chassis, the trailing edge extends to the outermost side of the bottom panel, and the upper edge slopes downwards; such as the McLaren MP4/13 and BAR002 (see below).
Both concepts have different functions, with a more front-facing wind-breaker plate having a more direct effect on the front wheel wake, which is designed to have greater benefits for the lower part. In the mid-to-late 2000-2010 period, as flow field analysis via CFD became more advanced, it was not uncommon for a car to have both of these schemes, and the frontmost wind breaker was renamed a rotary vane to avoid confusion in the team's internal documentation.
The schematic of the BAR002 shows the barge plates behind the front wheels
<h1 class="pgc-h-arrow-right" data-track="14" > the aerodynamic principle of the wind-breaking board</h1>
It is said that the sole purpose of the windbreaking plate is to control the front tire trail to cause great damage to the rear of the car as well as the bottom plate of the car, but it can be said that this is their original function. Since 1994, there has been a "no-go zone" around the front tires of the racing car, where the installation of any form of air power kit is not allowed. Before 2009, the "air exclusion zone" around the front tire was much smaller, and even after 2017, the rules added more room for development specifically for the wind breaker board.
Thus, from 1995 to 2008, the wind breaker could be very close to the front tire, thus directly affecting the shape of the tire wake. As shown in the image below, as shown in the figure below, in this case, as mentioned above, the more forward-facing windbreaker does play a crucial role in creating an airflow wash that prevents the front tire wake from being pulled into the baseplate and sucked in by the diffuser.
Effect of barge plates on the position of the Honda RA106 front tire wake
The secondary function of the wind breaker board, arguably the more beneficial function, is to act as a downward drainage device for airflow. The aspect ratio (AR) of the windbreaker, the aspect ratio is the ratio of wingspan to chord,
For rectangular wings, where b is the span and c is the chord. Due to the low aspect ratio, the blast plate produces a strong eddy tip, such as circulating (
The vortex formed is inversely proportional to the span of the "nose wing",
As a result of these strong eddy currents, the wind-breaking board produces many "induced resistances", which are also inversely proportional to the aspect ratio.
where e is an efficiency factor, with a rectangular wing of 0.7 and an elliptical wing of 1.0.
A lot of induced drag is often a negative factor in the car, however, the resulting eddy currents have a huge net benefit on the rest of the car to generate downforce as well as improve the overall aerodynamic effect, so they become crucial. The upper vortex can increase the airflow flow and the effective angle of attack of the front edge of the bottom plate, the purpose of which is to increase the suction peak, so as to suck the air flow around the bottom plate into the bottom plate to increase the pressure difference between the bottom plate and the bottom plate, thereby achieving higher down pressure on the bottom plate.
The advantage of counteracting the up and down vortex is that the airflow wash at the edge of the bottom plate increases further as the down-air components merge. Looking at the 2017-21 blast plate, it's easy to see its unique uses, with the upper half designed to generate airflow downwashing and the lower half directly generating downforce.
2008 Renault R28 under the base plate of the wind breaking board CFD simulation streamline
In 2009, in order to "clean up" the airflow around the front tires, reduce downforce, and reduce the negative impact of the tail of an F1 car, the rules were drastically changed to reduce efficiency in the wind-breaking board area. A larger design exclusion zone has been added around the front tires, which makes the development space for the wind breaker board much smaller. While deflection blades are still present, they can only be under the nose cone to reduce their impact on the front tire trail. However, this allowed them to interact with the newly formed Y250 front wing vortex, a windfall from a 2009 rule change that happened to enable the downwashing function of the blast plate airflow. The result is that the front tire exhaust area is much less complex, but the downforce lost is much smaller than expected in the new version of the rule.
Comparison of the wind breakers and front tire trails of the Toyota TF108 (left) and TF109 (right).
The curvature and slope of the front nose wing means that it has both a high-pressure side and a low-pressure side. The position of the hulls and breakers means that the low-pressure airflow behind them has an impact on other aspects of the car's aerodynamics. The blast plate creates a low pressure area that helps to reduce the pressure around the leading edge of the baseplate in order to increase more downforce.
In 2009-2017, after nine years of air power rules, especially since the introduction of the V6 turbo hybrid unit in 2014, the FIA introduced new aerodynamic rules. That means bigger cars, wider tires, bigger rear diffusers, and a more "aggressive" styling created by swept wings and bigger breakers; all designed to increase downforce, make the race look more attractive, and reduce lap times. It must be said that this has greatly increased the difficulty of overtaking, and it is hoped that the change in rules in 2022 will be corrected. Due to the greatly increased area of the wind breaker area and the greater freedom in the design of the body air force kit for the rest of the race car, the wind breaker became a key area of development; there were countless blades, stripes and swings that sprouted from both sides of the race car. When the 2019 rules simplify the front wing and front brake ducts, the design of the wind breaker plate becomes more intense, and the aerodynamic complexity increases again.
Williams FW43B introduces CAD's relatively simple blast plate and side tripod leading edge blade design.
While the barge plates have been nominally removed from the rules to make way for the "cleaner" lines of the 2022 F1 model, some of their features remain on the baseplate fence – the FIA allows cars to have up to four fences on each side of the front of the baseplate. These fences are essentially larger vortex generators, and their curvature helps to create low pressure around the entrance to the passage between the underbody baseplate and the ground in order to generate greater downforce.
So, although broken D-plates have been around since 1994, from 2022 their role will no longer exist, but their functions are being replaced by baseplate fencing.