In this week's Tuesday technical column, Mark Hughes explained the difficulties Ferrari, Red Bull and Mercedes will face at the Azerbaijan Grand Prix in setting up and why "the tail wing" will be one of the key topics of the weekend.
The Baku circuit is unique in that its contradictory combination of tracks leads to extreme conflict with the aerodynamic requirements. The full throttle section parallel to the Caspian coastline (including multiple false bends) is 2 km long, which gives the low pressure rear wing setting a lot of lap advantages.
But the middle stage through the historic old town is as tight as Monaco and requires maximum downforce settings. In terms of the requirements of the wing layout, this is a combination of two extremes: Monza with ultra-low pressure and Monaco with ultra-high downforce.
This means that there is no "correct" tail level here. Uniquely, the possible lap times are similar regardless of the low pressure setting or the high downforce setting. It just behaves in different ways. At least, that's been the case since the first game here in 2016. It would be interesting whether the cars with the new rules would do the same. The proportion of all the downforce in the new version of the car comes from the chassis is much larger than before.
Pictured here is Mercedes' bridge-oriented tail. It has an unusual, largely isolated main plane, as well as a wide lower surface. Unlike traditional spoon-shaped wings, its leading edge is raised in the middle. As a result, there is a difference in the distance at which air flows between the upper and lower surfaces. This increases the pressure difference between the upper and lower surfaces, which produces more downforce and greater drag at a given angle level.
In general, a low pressure setting seems to provide better lap times, but may increase the risk of rear wheel attenuation due to greater rear wheel slippage.
Last year, both Mercedes and Ferrari opted for low-resistance rear wing for the car. In a stage in the season when Red Bull is usually the fastest, Charles Leclerc gave his Ferrari ahead of Lewis Hamilton's Mercedes to pole position.
But Red Bull opted for a larger rear wing, easily becoming the fastest car in the race, with better tyre degradation.
Max Verstappen and Sergio Perez overtook Hamilton on the first pit stop and their tyres were still very strong in the final stages, thanks to the higher downforce tails giving them more protection.
Historically, the more competitive the car, the more likely the team is to bring more downforce here, and those who want to be competitive tend to bet on low-pressure settings, do their best to fight for the starting spot, and then try to maintain the track position. So, in the Super Season at Mercedes (2016-19), they carried a higher tail. In both 2016 and 2017, their rivals Ferrari and Red Bull were defeated.
Ferrari launched a fast racing car in 2018 and again in 2019 adopted a higher downforce setting than Mercedes. But in 2021, the situation reversed, and for the first time in Baku, Red Bull had enough confidence in the speed of its car itself, using a tail wing with a higher resistance than its opponents.
This is the low-pressure tail that Mercedes introduced in Miami and has only been used there so far. It can be seen that its main plane is flatter and has fewer radians compared to the standard tail with higher downforce.
This year, Ferrari and Red Bull have been leading the way in all of their track performances, compared to Ferrari, Red Bull tends to have a low-pressure rear wing setting and is faster at the end of the straight road, while Ferrari is faster in corners and accelerates out of corners strongly.
How will this happen in Baku? Does this mean that Ferrari's inherent high resistance, downforce, would cause it to fall to their preferred setting in the rear wing selection? Given the excellent performance of last year's high downforce setting, will Red Bull still use their inherent low resistance to give them an experience that high downforce is not often experienced?
Mercedes faces an interesting choice. Barcelona showed they tackled their dolphin jump, with the W13 fast enough and competitive on the straights. Combined with the low-angle rear wing setting, could this make Lewis Hamilton and George Russell tilt more toward qualifying than Red Bull and Ferrari? Even knowing that it could make sacrifices on the issue of tire degradation in races?
Mercedes launched their characteristic low-pressure tail in Miami, while in Baku they will choose between this tail and the one with the usually distinctly wavy contour.
As always, Baku brings an interesting multiple-choice question for the team, and there may be unusual competitive patterns in the weekend races.