Technical Roundup of the Season so far

Spa entertains the 12th F1 race of the season (31^st August - 2^nd September) which puts us just past the half way point in the season.

So far we have been privy to some of the best racing F1 has produced in decades. The reasons have been talked about in the past at length but mainly fall into 2 categories: Tyres and regulation changes.

Tyres

Firstly I’m going to say that I have no problem with the way in which Pirelli supply their tyres. The Bridgestone era for me was one that neutralized tyre effect and made F1 into more of an endurance class. Pirelli have taken their brief from the FIA and done precisely what was asked of them. They provide tyres with disparity between compounds unlike the slick Bridgstones of 2009. Pirelli unlike Bridgestone seem to understand that F1 fans know the difference between a race tyre fitted for performance and a road tyre fitted for more durability. As a consumer it leaves us no less inclined to purchase Pirelli road tyres and in fact those in the know will realize that Pirelli invest hugely when designing their products.

The teams/drivers complained in 2011 that the Pirelli tyres ‘grained’. Graining occurs when tyres are overworked, small beads of rubber form on the tyres surface which as the car is in yaw move across the surface of the tyre. These grains affect the feedback the driver gets from the car/tyres and can make a stint unpredictable.

For 2012 Pirelli listened to the teams and made alterations to the compounds, this eliminated the graining effect much to the pleasure of the drivers.

Pirelli also elevated the degradation level of all but the super soft compound which has led to some interesting races when people have reached what has become to be known as the ‘cliff’. The cliff is the point at which the tyre no longer affords any grip and the driver is left almost marooned on circuit needing to get back to the pits in order to fit a new set of tyres.

This will be controversial for those that have disdain for what some call the ‘Pirelli Formula’ but I personally would like to see an even larger disparity between compounds forcing the teams into more elaborate strategies. The loss of refueling in 2010 left a void in strategy disparity that the tyres are filling and as the teams work tirelessly to recover the rear downforce they lost from the Off Throttle and Exhaust Blown Diffuser bans the levels of degradation will lessen.

Lastly I’d like to say that again from a fan perspective rather than a tech one I think running in Q3 should be mandated even if this means a re shuffle of the compounds available at races. Currently it seems that drivers leave a race weekend with one set of the harder compound tyres unused and perhaps having that switched for the softer compound would alleviate the problem. The other option comes in the form of a Q3 qualifying tyre that is handed back to Pirelli at the end of the session.

This brings me to the one subject no-one really ever talks about and that’s the disadvantage a driver takes by being in Q3. When a driver qualifies in the top 10 he must (unless there’s a weather change) must start on that used set of tyres. This is where degradation and strategy plays a huge part in F1 for 2012. I have mentioned on twitter in the past when Seb has took pole by a fair margin, just how much did he take out of the tyres? This is of course relative when considering drivers in 11th and further back can select either the soft or hard compound and can use a set of unused tyres. This puts the lead drivers at a disadvantage as they have at least 3 laps on their grid tyres add to this the tyres have already been put through a heat cycle on their outlap aswell as the rigors of a qualifying lap, putting their wear life at a considerable disadvantage when compared to a Q1/2 runner.

 

Regulation Changes

Tie-ing in with tyre wear is the action the FIA took in order to ban Exhaust Blown Diffusers and Flexible Front Wings.

The FIA curtailed the use of engine maps in order to limit the amount of ‘Off throttle’ blowing the teams could achieve. Meanwhile they mandated the exit of the exhaust in order to stop teams from placing the exhaust in shrouds and being placed above the critical diffuser area to create more downforce.

As with everything in F1 the teams can’t simply unlearn what they already know and have continuously moved to alter their engine maps to gain advantage from Off throttle blowing. This is important in terms of aerodynamics as when the exhaust blows on certain parts of the car it will create downforce. When using off throttle blowing the aerodynamic part(s) getting blown gets a continuous airflow that allows a gradual drop off in downforce. Without off throttle exhaust blowing the downforce drop off can be dramatic which has an undesired effect for the driver in terms of balance. In order to regain some of the downforce lost without EBD the teams all devised ways of channeling the airflow exiting the exhausts at specific regions of the car.

In Melbourne it was clear that the McLaren exhaust solution which uses the Coanda effect to manipulate the airflow over and around the sidepod toward the exhaust channel was the one of the best solutions to this rule set. This option allows the airflow from above and around the sidepod to converge with the airflow around the exhaust which will in turn energise the flow increasing en-mass the amount of airflow over the rear of the floor in turn aiding the diffuser effectiveness.

Just to prove how effective the McLaren style of exhaust is Sauber (who had praise from Adrian Newey for their original ramp style exhaust) moved across to the McLaren style exhaust with almost all of the teams now sporting a similar design.

Both Ferrari and Red Bull have perhaps had the most protracted battle to get an effective exhaust solution with Red Bull suffering the most in terms of losing downforce under the new regulations. Red Bull really pioneered the return of EBD in 2010 and have reaped the rewards for the last two seasons. Having this removed was a hammer blow for the team who were looking for a hat trick of Constructor and Drivers Championships and had extracted a large amount of performance from the system over the championship winning seasons.

Exhausted? You will be, let’s have a look through the process some of the teams have taken up until now to extract more performance from the exhaust gasses expelled from their engines.

 

Red Bull

The Red Bull design team led by Adrian Newey approached the new exhaust rules with lateral thinking, the original design of their exhaust solution featured a cross over tunnel which the team hoped would encourage airflow coming from around the side of the sidepod to enter the tunnel and exit into the area behind the exhausts exits. This airflow should converge with the airflow downwashing over the sidepod and create a mass flow area over the rear of the floor onward to the diffuser.

The problem with this first iteration of the tunnel was the airflow wasn’t flowing through the tunnel as predicted and instead choking the tunnel and forcing more air toward the rear tyres. This effect was compounded in Yaw as the tunnel flow became unpredictable and made life difficult for the drivers in terms of feel and balance.

During the China weekend the team decided to split their strategy and continued with Mark persisting with the tunnel bodywork whilst Sebastien trialled a much more neutral exhaust placed higher up on the engine cover bodywork leading to a more neutral aerodynamic effect.

For Bahrain the team decided to run a bodywork configuration without the tunnel bringing their ramped solution. They also added some holes next to the rear floor / tyre strake in order to better control the effects of ‘Tyre Squirt’. This was simply an interim solution put in place whilst the team redeveloped the tunnel concept back at the factory.

At Barcelona the team introduced a revised tunnel configuration which elongated the tunnel but more importantly the airflow entering the tunnel would now be sent through the engine cover and released out of the starter hole. This should have stopped some of the issues the team were getting with the convergence method used previously with the downwash and exhaust plume having their own space to flow over the rear floor.

The concept although sound in CFD and the Wind Tunnel was not translating to results on track, once again it appeared that the system was choking itself with too much airflow. This was more apparent when Mark picked up some rubber that blocked off some of the starter hole and changed how the car behaved.

Monaco and the team continued with the same tunnel configuration but increased the size of the holes in front of the rear tyre. This was the final straw for some of the teams who believed Red Bull to be contravening the regulations. Unlike Sauber and Ferrari who use slots in front of the wheel to aid with the reduction in ‘Tyre Squirt’ Red Bull weren’t creating a break in the floor. Although not a huge advantage by itself not having the break would give a better result than with the slot. On advice from the FIA the teams didn’t protest the Red Bull holes and so the Monaco result remains the same. However after the race the FIA clarified their stance on the holes and told Red Bull to remove them from their car for Montreal. I wrote an article at the time on the subject to explain ‘Tyre Squirt’ http://somersf1.blogspot.co.uk/2012/06/red-bull-tyre-squirt-duct-part-2-now.html

Montreal saw the team race once again without the tunnel configuration and the removal of the tyre squirt holes in front of the rear wheels as requested by the FIA.

Valencia had the team bring another new iteration of the tunnel concept. This time the entrance had been split into two sections the leading tunnel a much larger section following the contour of the sidepod and the latter a continuation of their previous boxy design. The tunnels theirselves are ducted inbound with the larger exiting through the starter hole and the smaller tunnel exiting through the lower engine cover cooling exit. A raft of upgrades were made at the Valencia weekend and so I produced it’s on analysis at the time: http://somersf1.blogspot.co.uk/2012/06/red-bull-valencia-gp-technical-analysis.html

Since then the team have simply been refining the concept with a revision to the exhaust channel in Silverstone (increasing the height of the exhaust channels)

I think it would be fair to say that throughout the first half of the season Red Bull have been the team challenging the FIA’s resolve in terms of engine mapping in order to gain an aerodynamic advantage. This came to a head at Hockenheim when the team ran a torque map that was massively different between 10,000-14,000rpm than the one used at the previous race at Silverstone. The map used in Germany produced less torque during this range which would help with both driveability and produce more exhaust gas. In response to this the FIA decided that each team would have to provide a base map from one of the first 4 races of the season of which they can vary the performance by 2%.

 

Ferrari

Ferrari started work on their 2012 challenger much earlier than usual last season in order to get a head start on the their rivals, stating they were taking an aggressive approach to the design of the F2012.

The initial design of the exhaust didn’t work as well as was intended and so Ferrari have been in a battle to find a better solution ever since. The original ‘Acer Duct’ design as it became known due to the sponsorship adorning that section of bodywork had the exhaust placed inside the duct toward the outer edge (Seen on the left in Mario’s great diagram below) The idea behind this exhaust solution was to use the airflow from the sidepods to create a larger airflow pattern. (This airflow in previous seasons had been vented into the coke bottle region via a lower engine cover outlet) The problem with this is airflow speed, the exhaust gas was meant to aid the airflow but it would appear the airspeed differences were too large and the result inconsistent. I can’t conclusive say if it’s the whole reason why but Ferrari’s radiator layout for 2012 is vertical an approach that is unusual in modern F1 with teams instead modifying the radiators to lay at 45 degrees and beyond. This radiator layout is something that has also been employed on the Sauber C31 for this year and is most likely an engine requirement rather than an aerodynamic one. Having the radiator in the vertical position means you will slow the airflow.

After the pre season Barcelona tests the team moved the exhaust more central in the Acer Duct as they were having problems with the exhaust plume heating the rear tyres causing higher levels of degradation. (Shown on the right hand side of Mario’s diagram above)

The team continued to make alterations to the Acer duct in order to further influence the exhaust effect whilst a new solution was being worked on back at the factory. At the Mugello test Ferrari debuted their new configuration which had a more conventional (for 2012) outward exhaust channel, abandoning their idea of mixing cooling and exhaust flow internally this exhaust would manipulate the airflow coming from above and the sides of the sidepod. They however shrewdly still continued to use the sidepod cooling flow with ejector holes placed in and around the exhaust channel. These ejector holes help to manage the airflow toward and onwards from the exhaust plume. Furthermore they added similar holes around the coke bottle area in order to control the airflow in this region.

In Montreal the team finally converged on their version of the McLaren style exhaust with the exhaust channel helping to guide airflow from the downwash and from around the sidepods into the coke bottle region. Ferrari continued with their cooling ejection ethos in order to further enhance the effectiveness of the exhuast plume. Within the exhaust channel two holes were placed above the exhaust exit in order to further bend the airflow downward whilst on the side of the bodywork Ferrari have played around with several ejector holes / positions in order to further attract more airflow from around the side of the sidepod toward the exhaust plume.

McLaren

McLaren’s exhaust position was recognised early on as the leader in terms of overall effectiveness who now have Sauber, Toro Rosso, Force India, Caterham & Marussia all using very similar design concepts whilst Williams who have trialled the solution on several occasions continue to use their own design philosophy.

McLaren introduced an alteration to their existing exhaust configuation at Hockenheim with a larger undercut at the rear, encouraging more airflow travelling around the side of the sidepods to pull inward toward the coke bottle region.

 

Lotus, Mercedes & Williams

These three teams are left following their own design paths in regard to exhaust aerodynamics.

Lotus have opted to place their exhausts in a fairly neutral position much higher up in the engine cover bodywork than most teams. Although it would first appear with the exhausts in this position the plume will head toward the rear wing the airflow moving over the sidepods and engine cover in front of the exhausts will more likely concentrate the exhuast plume toward the beam wing and coke bottle region.

Mercedes as in previous seasons have been slow to revise their car in order to attain better performance from the exhaust aerodynamics. Since launch the team have run with an exhaust in the position that perhaps the FIA were looking for the teams to use. Placed on the top rear edge of the sidepod the exhaust uses airflow travelling over the sidepod (downwash) in order to bend the flow down toward the rear floor.

Williams like Ferrari are utilising the potential of exiting sidepod cooling into the exhaust region in order to manipulate the exhaust plume resulting in the airflow bending down over the rear of the floor. When Pastor had an engine failure back in China and the exhaust plume was visible it gave us the opportunity to see where the plume travels.

 

Other Developments for 2012

Step Nose: The Step nose is a development born out of a rule change made by the FIA to further increase safety in the sport. Without Exhaust Blown Diffusers the teams are eager to drive as much airflow at the floor as possible. In order to do this it is necessary to have the nose tip as high as the rules allow. However due to the constraints further down the nosecone a gradual curve as we have been used to wasn’t efficient. It is purely an exercise in co-efficiency over aesthetics and so most of the teams have an unsightly step in their nosecone. Both Red Bull and Sauber can up with ways of limiting the aerodynamic side effects of the step nose whereas McLaren bulked the wide convention in the first few races and ran with a much lower drooping nose. When McLaren’s tea tray area came under scrutiny in China and the FIA asked them to redesign it McLaren also set about looking into adopting a higher nose. Mugello offered us the first glimpse of the McLaren higher nose tip but unlike the other teams McLaren still continued to have a shallow curve to their design.

Vortex Generators: The use of Vortex Generators atop of the sidepods have now become common place, these little fins help in several ways but chiefly they reduce lift on that region of bodywork by disturbing the airflow pattern whilst also by being positioned correctly, alter the attitude of flow toward the given exhaust solution further downstream. Used initially by Lotus all but Mercedes, Ferrari, Marussia and HRT feature similar designs. Most teams started with 2 Vortex Generators but some teams now have added a third in order to better utilise their advantage. Although new to F1 in this guise the devices have been used in aerospace for a long time. They are usually used in order to balance a poor performing wing span, in the picture below we can see the effect Vortex Generators have at different AoA’s and airspeed.

Mercedes DDRS/Super DRS: DDRS implemented by Mercedes initially gave them a qualifying advantage, as the season has progressed and others have recovered some rear end downforce they seem to have lost some of that advantage. I recently wrote an expansive article on Mercedes in which I explain my theory behind DDRS which can be found here: http://somersf1.blogspot.co.uk/2012/08/the-trouble-at-mercedes.html

Lotus Passive F Duct: Lotus have been experimenting with another Drag Reduction System since Hockenheim which in theory is more like the F Ducts of 2010 reducing drag on the lower wing plane but this device works passively. I have also written an article on this subject which can be found here: http://somersf1.blogspot.co.uk/2012/08/lotus-e20-passive-f-duct-system.html

Ferrari’s Pull Rod Front Suspension: Ferrari were one of the last teams to introduce the pull rod suspension at the rear of the car which Red Bull have been using since 2009 however Ferrari stunned most at their car launch with the adoption of the same at the front of the car. Ferrari promised throughout the development of the F2012 it would be radical and this front suspension choice has been the topic of many conversations so far this season. Ferrari’s adoption of the pull rod front suspension is most likely due to the designers realising that more heat can be generated with this layout. Furthermore Pull Rod suspension offers a better Centre of Gravity which always helps when considering the evolving platform of an F1 car throughout a race.

Perhaps the most overlooked reason Ferrari may have adopted Pull Rod suspension is Fernando was the last F1 driver to utilise the layout. In his maiden year driving the Minardi PS01 Fernando out drove his team mates and was notably quick during qualifying. Does this add up to Ferrari’s adoption of pull rod front suspension? Maybe not but as we know Fernando already had the team add stabiliser bars to the engine to add torsional stiffness (a trick from his Renault days) This may have also attributed to Felipe Massa’s early season dismal form who took til as long as Monaco to find a setup that suited his driving style.

Pit Stops are a crucial aspect of F1 with McLaren having the benchmark time of 2.4 seconds marking the quickest pit stop ever at the German GP. That however comes off the back of quite a disastrous start to the season in the pit box with several errors over consecutive race weekends. At the start of the season Ferrari were the ones to watch in the boxes averaging 3 second pit stops. There are several reasons for these super quick pit stops other than the amazing pit crews performing super human feats:

Nut in Wheel Solutions - with helium banned as a method of powering the wheel guns the teams have looked laterally at ways to speed up the process once more. The nut in wheel solution (already ran on the Mercedes during 2011) is now used by most of the top teams in order to reduce the amount of work carried out by the technician and to lower the chances of error. The system however isn’t fool proof and can still fail as shown when Schumacher retired at China when the nut didn’t seat correctly.

Jacks - An area that gets attention as they can help speed up the process, we got used to seeing the Mercedes swivel jack last year and now other teams have started to put efforts into extracting time from the devices.

Lighting Systems – Used to tell the pit crew and/or drivers when the wheels are fitted and jacks are down in order for everyone to work more fluidly.

In Summary

This season has provided us with not only great racing but from my point of view some great technical advances. In my next article I’ll look at what we may see from the teams for the rest of the season and beyond.

Images Copyright www.Sutton-Images.com / Mario Keszeli

Author: Matthew Somerfield

Twitter: @SomersF1

Blog: www.somersf1.blogspot.com