It’s been an exciting couple of weeks for F1 fans as teams have begun to unveil their 2010 challengers.
From a technical point of view, 2010 should be a belter. Teams are still learning what works and what doesn’t after the radical technical overhaul last year. Now that the double diffuser is legal aerodynamicists have the opportunity to design their cars around the device – expect to see some radical solutions.
Add to that a couple of subtle rule changes – in particular no refuelling, the loss of KERS and narrower front tyres, which has the potential to mix up the grid.
Its no surprise to see teams borrow the best bits from the 2009 cars – the high Red Bull v-nose, the double diffuser, outboard mirrors, heavily undercut sidepods, double endplates – but these features are tied together in trying to achieve two outcomes.
These are getting more air to the rear of the car, and in particular the diffuser, and managing the air flow around the front wheels, which are a major source of drag.
The diffuser
Forcing air under the car speeds it up and creates low pressure. The diffuser is a piece of kit towards the back of the car that returns this high-speed, low pressure air to freestream. This is done by allowing the air to expand in a controlled manner. Typically the larger the diffuser, the more air can be accommodated through the floor, the lower the pressure and the greater the downforce. ‘Double decker’ diffusers allow complex structures above the floor to help manage this airflow. It’s not only air to the diffuser that’s important but airflow over it. Getting fast airflow over the top of the diffuser is critical to generating suction. The beam wing – the aerofoil below the main double element rear wing – works in tandem with the diffuser by creating low pressure at the diffuser’s exit. This reduces the pressure differential between the diffuser and freestream making the rear of the car more efficient – the wing acts to pump the diffuser. Bargeboards and undercut sidepods also play a critical role in managing air to the diffuser. Undercut sidepods with a tight, heavily tapered coke-bottle zone translates into a more consistent, higher-speed airflow to the rear of the car. This is why Red Bull elected for pull rod suspension on its RB5 – it allowed for tighter packaging at the rear of the car (although wasn’t conducive to retrofitting a double diffuser).
The Tyres
The narrower tyres will increase straigh-line speed by reducing drag. The equation is simple – less surface area presented to the oncoming air equals more speed. A second effect is that a higher volume air can funnel between the tyres (space between the tyres has increased by 50mm in total), which will improve the efficiency of vanes and bargeboards in this region. However, this comes at the cost of lower front grip, which affects cornering speed. The net effect will be to give the car more of an understeer feeling. As in previous years the temptation for teams is to ensure a forward weight bias to control for this. The intent of the rule change is to flip the balance back towards the handling characteristics of the 2008 cars, where the grooved tyres resulted in less front grip. Unfortunately the cost for the teams will be substantial. One feature of 2009 technical development was the proliferation of front wing endplate designs. Given the ever tightening regulations there were few areas of technical freedom where designers could claw back downforce. Managing air around the tyres was one of them – hence the complex detail of the endplates with teams spouting all manner or wierd and wonderful vanes and flicks in this region. The rule change for 2010 means that designers need to re-base their knowledge rather than simply copy last years’ solutions.
Ferrari F10
Very few teams have published detailed specifications of their machines so it is hard to get a read on wheelbase, but the F10 appears to be one of the longer cars in the pit lane. Compared to the F60 the F10 is more tapered in the coke-bottle zone, which means the diffuser should work better. Ferrari has adopted a longer gearbox as a way to optimise the diffuser and this is one of the reasons for the more tapered sidepods. Ferrari has also heaving borrowed from the Red Bull school of design with the V-nose. The V-nose does two things. The regulations specify a minimum width and height for the chassis by the footwell area. The V-nose raises the outer part of the nose which allows the bottom of the nose to taper to the centreline. This creates more space between the front tyres and the chassis optimising the airflow. The second effect is that the V-shape reduces lift on the nose by containing the air. The concave shape of the nose induces lift so by keeping the flow inline with the nose (which is what the V does) the lift is less. The F10 is strikingly simple. The diffuser isn’t as intricate as others and the two-piece front wing lacked the fins and extra mini-decks we’re used to. No doubt the body shop is working overtime on upgraded parts for the later tests and the Bahrain GP. Also the sidepods look a bit bulkier than the competition – although that may be a photographic trick. The Ferrari was fast out of the box in Valencia and the consistency of lap times was impressive – if testing form continues into the race 2010 could be a good year for the Scuderia.
McLaren-Mercedes MP4-25
The MP4-25 is the most radical new car – so far (who knows what Adrian Newey might reveal later this week). Although the Woking outfit is one of the few teams to not adopt the V-nose there are plenty of other features to get excited about. First that overly-sophisticated diffuser. McLaren has publicly acknowledged that it pushed the diffuser regulations to the limit and the resulting device is highly complex. The diffuser balloons out of the rear of the car and joins the beam wing. Although there are few close-up shots there a couple of different channels with a range of flicks and vanes. The detail is classic McLaren. One risk of such a complex device is that it may lack consistency across a range of speeds and corners. To the chagrin of some fans the MP4-25 sported a shark fin. These fins serve two purposes. During cornering, air is directed so it is ‘normal’ to the rear wing, which improves downforce. Fins also reduce lift over the engine cover by ensuring a lower pressure zone isn’t created on the leeward side when turning. Two final things to mention on the McLaren: the endplates and the snow plough. The McLaren endplate sports a drooping vane from the top edge of the plate. It is incredibly intricate on its outside and is different to the double-vane favoured by many teams last year. The effect is similar – namely to push air around the tyre and set up a vortex to control airflow. The addition of the snow plough is intriguing. Williams conceived the device last year with the aim of controlling flow under the nose and spilling it under the floor to feed the diffuser. No other team adopted the device so it was a surprise when the eggheads at Woking unveiled it on the McLaren. The McLaren implementation is a little different as the plough appears to merge into the chassis. The theory is to better control the air feeding the sidepods and floor but the risk of such a contraption is, again, consistency. Trashing the air under the nose is a sure fire way to wreck the performance of the diffuser. I’ll be intrigued to see if McLaren keeps the snow plough and if other teams pick up the device.
Mercedes W01
Mercedes, like Ferrari and a host of other teams, have also adopted the V-nose. Interestingly the front part of the nose appears to droop and is lower than that of other teams. This droop is to try to force air between the nose and wing which then expands into a venturi between the wheels. The theory is similar to the Brawn solution last year, although the implementation is different. This will counter some of the lift produced by the nose although, ironically, the droop shape will create more lift. High noses are all the rage this year. Again this treatment should allow a more consistent flow of air under the car to the floor. And guess what that means? A more effective diffuser. Perhaps more interesting is the re-emergence of single keel suspension. When raised noses first came into vogue designers placed a keel below the nose to attach the lower suspension arms to. This kept the integrity of the suspension geometry but at an aerodynamic cost. Eventually teams figured out that the aero compromise was too large and changed the suspension geometry to connect direct to the chassis. The W01 has a small keel in at attempt to improve the suspension and the loading on the tyres. The chamfered V-nose allows this implementation and it will be interesting to see if it is a one-off or if other teams follow. The two other innovative features sported by the Mercedes W01 are the air box and engine cover. The engine cover is a hybrid between the classic tapered cover and the shark fin. The W01 looks like it has a razor blade (or perhaps a Stanley knife) emerging from the top of the airbox. The principle is the same as the shark fin – to control flow to the rear wing and mute lift. The other innovation is the airbox. The airbox usually incorporates the roll hoop but the hoop is now a thick vertical support on the centreline of the car. To cool the car there are openings either side of this support – the airbox is effectively split in two. In addition there are some openings a bit further back allowing cool air to seep over the engine cover. At this stage it is unclear exactly its purpose but it is likely to help cooling with some of the engine and ancillary components that have been moved rearwards e.g., the oil pump.
Sauber
BMW Sauber Ferrari is quite a mouthful, isn’t it. But boy, the car looks sleek. The 2009 BMW suffered acutely for poor aerodynamics because of the adoption of KERS. The bulky sidepods required for cooling the KERS unit prevented sufficient air getting to the diffuser. This was compounded when the double diffuser became standard issue. Allied to that was a woeful belief in how to best manage airflow around the front wheels as the team persisted with an ugly box-like endplate until the Singapore Grand Prix in September. By contract the new C29 looks like a solid machine, albeit without any revolutionary design innovation. The vastly reduced budget will likely further hamper aero performance and on-going development. Head-on the car looks stunning – it is a simple design with a high nose showcasing the tight sidepods with a heavy undercut. The philosophy is to ensure that as much air gets under the nose as possible to feed the floor and diffuser. The heavy undercut in conjunction with the bargeboards help channel air around the sidepods to the double diffuser. The coke bottle zone to the double diffuser is extremely tight, which again reduces drag although being too extreme in this area could lead to airflow separation. The C29 front wing is suitably developed and is an evolution of the F1.09 from last year. At its core the team does have a very strong engineering department as confirmed by a competitive 2008 package. I wouldn’t be surprised if the 2010 car started off well but it will probably suffer in the development race.
Renault
One thing you can say about Renault is that it is good to see the car’s classic yellow and black livery back. Aerodynamically the 2010 car is as conservative as the 2009 machine was unwieldy. The nose is the most striking part of the car and not for its sleek aerodynamic look but rather for its heavy-set appearance. The R30 looks slightly more elegant than the R29 and the intent is to try to create a venturi effect below the nose that should provide downforce. The launch front wing is interesting. Outside the FIA mandated central section the main plane is raised before tapering towards the endplates. This reduces overall downforce (the ground effect is reduced) but creates a more consistent device particularly when cornering and in turbulence. Initial reactions post-launch were that the Renault was one of the shorter cars. As a result the bodywork doesn’t look as tight as some of the other teams – particularly Ferrari and McLaren. Although the Enstone outfit hasn’t released wheelbase dimensions if true it would account for the more bulky packaging. The one advantage of a shorter wheelbase is that it allows better optimisation of weight distribution, which could be important as the car must operate over a wide range of fuel loads. In particular the sidepods look bulky with significant curvature at the leading edge which may induce lift. The most innovative thing about the R30 is its rear wing. Renault has adopted an M-shaped wing. The M shape optimises for the angle of the oncoming air but could result in transverse airflow which hampers performance. No doubt other teams are running simulations at base to work out whether it is a direction worth investigating.
Williams
Strangely, Williams has decided to radically overhaul its car despite having a reasonably good offering in 2009 – particularly in the early part of the season. The question at Didcot isn’t initial pace but rather development speed of the car. Williams has raised the chassis and now has the ubiquitous Red Bull-style v-nose to both reduce lift on the top of the car and increase airflow clearance between the tyres. In addition between the front tyres there is a snow plough device albeit different to the McLaren interpretation. The Williams version rises from the base of the car and is designed to channel air to the floor and feed the diffuser. It is hard to see and is less overt than McLaren’s. The FW32 is a good example of how the 2009 regulation changes failed to curb the use of bargeboards and pod wings. The boards are considerably larger than they were last year and also feature a sawtooth shape to create vortices which smooth airflow around the sidepods and effectively seal the floor. The 2009 rules defined areas where bargeboards weren’t permitted. Car designers simply changed the length and configuration of the sidepods which resulted in flow conditions sprouting up in regions not covered by these black out zones. The other big change for Williams is the switch to Cosworth engines. We won’t know until the first few races how competitive the Cosworth power unit is but given that the Toyota engine was one of the more underpowered units on the grid the Cosworth shouldn’t be a downgrade. The more pressing issue is likely to be fuel consumption given the unit has had little development for the last four years.
Red Bull
In 2009 Red Bull vaulted from mid-table to top of the pack based on some inspired Newey design work. The pull-rod suspension and high, slender, innovative v-nose gave the RB5 a genuine performance edge which, once integrated with the double diffuser, turned into an invincible package. The RB6 is based on the same strong foundation which means it would is likely to be a contender at least in the early stages of the season. To the surprise of many Newey has kept faith with the pull-rod suspension systems. The advantage of the pull-rod is that it connects to the lower part of the chassis and thus allows a slimmer coke-bottle zone, which is good for rear downforce – both wing and diffuser. The disadvantage is that there is less space for the double diffuser. A closer look at the RB6 diffuser shows it to be far less intricate than the McLaren’s. The new car has retained the v-nose – in fact the 2010 incarnation is a far more aggressive version. This allows the underside of the nose to be v-shaped which improves front wing performance and better feeds the bargeboards and floor with air that has been less disrupted by the tyres. The bargeboards are quite large helping to seal the floor beyond the sidepods as well as feed the diffuser. At the rear of the car there is a odd shaped central exhaust structure. This will blow fumes over the rear wing and will impact the aerodynamics, often for the worse. Typically the acceleration variance means that it is hard to get consistent airflow from the exhausts over the wing so teams have shunned this solution. The key challenge for Red Bull this year is whether it can out-develop McLaren and Ferrari. The Milton Keynes-based outfit did a great job against (an impoverished) Brawn team so going up against the big guns could be different.
Virgin Racing
The VR-01 is the first car designed entirely with Computational Fluid Dynamics (CFD). Nick Wirth’s track record with the technology has been nothing short of amazing but going CFD-only in F1 is a risk. The correlation between computer, track and wind tunnel are all critical to designing and developing the car, and by relying on one technology and not having much track time the odds of success are small. Still the car doesn’t look that bad and has a nice livery. Most noticeable is the very long v-nose, which is more U than V shaped. The purpose is the same – (1) to contain air on the top of the chassis which reduces lift and (2) to create more space between the tyres to increase front wing efficiency.The other noticeable feature is the relative simplicity of the front wing – it’s almost BMW F1.09-basic. It has a very long chord section capped with simple endplates. There are none of the raised winglets that adorn the RB6 for instance. Given the criticality of the front wing to overall aero performance it would be a surprise not see an upgrade early in the season. The sidepods start off with a reasonably heavy undercut but soon fill out aft. Usually the undercut continues to the coke bottle zone which helps floor efficiency. It’s one thing designing the car with CFD but optimising the ancillary components to hone the aerodynamics will take time to get right. The first few rounds of testing suggest the VR01 has serious reliability issues – hydraulics has been a problem since day one and despite ongoing assurances from the team engineers have yet to be solved. Aero performance could be the least of Virgin’s worries – Branson’s 2010 F1 experience will be different to his 2009 experience!
Force India
The VJM02 was a good car with low drag characteristics that suited perfectly the low downforce configurations of Monza and Spa. The task for the Force India designers was add a shade more downforce so it could challenge across a broader range of circuits. Naturally the VJM03 is an evolution of the VJM02. The look of the car is similar – nose style, pod wings with integrated mirror, front wing, shark fin, vortex generators. Like McLaren the team has shunned the v-nose preferring a lower drag flat-nose. The integrated pod-wing-mirror, modelled on the F60, first appeared last year and has been retained. The pod wings help shape airflow around the sidepods to the floor by calming the air coming off the front wheel. Look at a raised front view of the car to see the alignment of tyre to podwing. The integrated mirror is a neat solution that reduces drag albeit at the extent of driver visibility, but who cares what is behind you when overtaking is so hard. It’s an interesting coincidence that all the Mercedes powered cars have odd-shaped airboxes. Force India’s is mounted on four pylons, which in theory should allow air to flow out more cleanly over the engine cover. Given the dawn of a few new teams in F1 and the extension of the point system this expect the VJM03 to score a few points this year.
Lotus
It’s good to see the Lotus name and the yellow and green livery return to Formula 1 even if it is a very different team to Colin Chapman’s outfit. Still the team is well-funded and has Mike Gascoyne on board who has close to 15 years of F1 experience. Many pundits predict Lotus to be the best of new teams. From the front the car looks a little like the launch version of the RB5 albeit without the v-nose. The high slender nose results in a wide gap between the standard section of the front wing and the lowest point of the chassis which helps funnel air under the nose to the bargeboards and floor. The front wing also appears highly developed (far more so that the VR01) with a number of tiered winglets and some flicks on the outside of the end plates. The flicks on the endplates control the downforce consistency of the wing. Whether they add much downforce is debatable especially given the complex feedback loops between the wheel and the wing. Going aft all similarities with the Red Bull end. The car seems extremely boxy. The pod wings are angular rather sculpted, the engine cover is flat and the sidepod undercut is shallow. The lack of undercut means that it is harder for the bargeboard to work properly – the pressure differential between the leeward and windward side is less resulting in smaller vortices rolling off the top and bottom. The flat engine cover is also more likely to induce airflow separation which means the diffuser and rear wing will work less well. Unlike Virgin Racing at least the car seems reliable having notched up plenty of laps during testing. Scoring points any time soon looks a long shot given the level of development of the car.
Who’s in the lead?
In short it’s impossible to know, especially given the far greater fuel load variance than in past years. However, my looking at lap times across the longer runs it’s possible to work out who has a nose in front. More so than previous years outright pace isn’t necessarily the critical performance element. Consistency is important and so is tyre wear. A car that works well on low and high fuel and is easy on its tyres is a better bet than one that can has extraordinary single lap pace. In terms of consistency Ferrari seems out in front. The Scuderia has had more running that other teams and over long runs the lap times are impressive. McLaren isn’t too far behind the the MP4-25 seems slightly harder on its tyres than the F10. A long run comparison at Valencia showed the two cars equally matched for the first 30 laps or so but then for the last 8 or so laps of the run the Ferrari continue to improve its lap times while the McLaren fell away badly (on the same tyres). Red Bull seems to be up there too although Mercedes is a few tenths off the pace. Ross Brawn put this down to weight distribution issues. The 2010 car requires weight distribution 1-2% back compared to the 2009 design and the Brawn engineers may have got the initial calculations wrong – although not disastrously so.
Weight distribution – a clarification
Those of you who avidly follow the comments may have noticed a debate between me and a few readers about weight distribution of the 2010 cars. It’s probably worth my clearing up the issue. Ever since the advent of the Bridgestone control tyres in 2007 teams have had to run a more forward weight bias. The need was compounded in 2009 with the introduction of slick tyres. In essence moving to slicks gave the front tyre more grip relative to the rears. In order to avoid overworking the rear tyres weight had to move forward. The greater grip at the front was also a cause of oversteer, which is why 2009 cars were reputed to ’suffer from’ excessive oversteer. The 2010 regulations attempt to address the weight issue by making the front tyres narrower. Also the longer wheelbase helps. A longer wheelbase car results in weight moving back. The other issue with a long wheelbase is that a heavier structure is required so there is less scope for moving weight around. The net effect of these changes is that teams still face a significant challenge with keeping weight distribution forward. However, the optimum weight distribution is expected to be 1-2% further back than last year.
(although she watches it too)
