One of the key design features of this year’s Mercedes W07 is the introduction of an S-duct. The S-duct was first seen in 2012, with Sauber using it as a way to manage airflow over the stepped nose. The idea was that airflow would be less likely to detach from the chassis if air was introduced behind the step. This was done by channeling airflow from underneath the car to a vent exiting backwards above the front bulkhead via an s-shaped duct in the nosebox, hence the term S-duct.
With just two weeks of pre-season testing the teams have had an incredibly tough time making sure not only that their new cars run reliably and that they correlate with what the data has shown back at the factory, but also assessing new components ahead of the first race.
Mercedes covered over 3,500 miles across both tests in Barcelona, putting one of the sport’s biggest outfits in the prime position to try out some aggressive concepts well before the season opener in Melbourne. During the second week the W07 was clad with plenty of complex devices, particularly around the sidepod area.
It’s been a while (exams have got in the way), but I’ve finally managed to put some new content together! In the following video I discuss why the 2017 regulation changes may not be as good as we first thought.
This is only my second proper video so I’m really keen for your thoughts on whether I should do more (or not), or any topics you might what to know about in the future. Please let me know in the comments on this post, or on YouTube or tweet me!
Note: This is predominantly my tech article I posted on Richland F1 last week, as I’ve had university assignments due in left, right and centre! I am back home this weekend so you should see some ‘What can we expect in F1 2016?’ posts very soon and, YES, there will be more YouTube videos. 🙂
F1 as we know it in 2015 may well be done and dusted, but being the relentless sport that it is it was hardly surprising to see small changes and tweaks during free practice on Friday, most with a firm suggestion of 2016 about them. In this final Tech Highlights post of the year, we will explore what McLaren, Lotus and Mercedes could be developing over the winter period.
The final grand prix of the season was arguably the most competitive McLaren have been all year, despite the two huge back straights. The car came alive in sector three and the on-track data lined the MP4-30 as the third quickest chassis on circuit. For Jenson Button to be disappointed not to make Q3 – a feat they failed to achieve this year – underlines the progress they have made in recent races.
Whilst Fernando Alonso may have been quoted saying half the car in Abu Dhabi was 2016 specification, this is most likely an exaggeration. However there were some significant changes made to the chassis which point towards their ideas they are developing over the winter.
Although it is not a complete overhaul, the rear suspension geometry has been modified to a more conventional setup in comparison to the rest of the grid, shifting them away from the offset lower wishbone placement that was used for aerodynamic purposes. The lower wishbone’s trailing arm remained attached to the rear crash structure, but the leading arm now reaches much further forward rather than the previous horizontal position.
It was clear that the development was in prototype stage, as the metal wishbone was exposed to the airflow passing over it when traditionally a carbon fibre aerofoil embodies it. However it must have required some substantial work to implement it with the current sidepod design and gearbox.
Traditionally the external suspension components mount to the gearbox, so any geometry changes must require a gearbox change as well. Both McLarens were not penalised for such a change, so I presume that the team have copied Mercedes in using a ‘cartridge’ style gearbox: a modifiable (and lighter weight) case surrounding the actual gearbox that is inserted separately.
With both championships sewn up long ago, it is clear that their attentions have diverted towards next year with a number of recent modifications around the front suspension being the most eye-catching. These changes have coincided with an apparent switch in development philosophy that began after their off-colour Singapore weekend at the end of September.
With tyre pressures now slightly higher than normal to counter any safety concerns, the W06 appears to be a bit more sensitive to setup changes and tyre temperature. Since Singapore they have adopted a new strategy to keep the tyre temperatures and pressures where they want them to be before heading on track, surrounding the hubs with an electrically heated jacket before putting the wheels on. This helps the tyre maintain core temperature and prevent a drop in pressure as they are measured when stationary, allowing the team to run the absolute minimum pressure.
However, the detailed work that has gone on around the front suspension has also got us asking further questions as to how they are approaching 2016. Above you can see just tucked inside the chassis is a spring that connects each pushrod together – this is the heave element.
Throughout this year Mercedes have run a hydraulically damped coil spring as their third element but in Brazil and Abu Dhabi the team trialed what appears to be a fully hydraulic device to control dive, i.e. when the car pitches forward under braking, which can be easily identified as a gold coloured cylinder.
This setup allows the engineers to finetune the heave element’s compression and rebound characteristics alongside the individual dampers, which could help the driver trail brake into corners later. This is something Nico Rosberg tends to do more than Lewis Hamilton, which is perhaps why the Briton has not been happy with some of the apparent developments that have come through recently.
However there is also the suggestion that Mercedes are attempting to recreate the effects of FRIC (front-rear-interconnected) suspension, a passive way of stabilising the car through high loading corners whilst maintaining a supple kerb-riding nature which was banned in mid-2014. This was done by connecting dual chambered dampers to eachother to keep the car’s roll to a minimum.
Along with the new heave element, there were also rumoured changes to the dampers and rockers to create an entirely new mechanical philosophy at the front end of the car – I am very much looking forward to the first pictures of the exposed front bulkhead of the W07 in Melbourne next year!
Mechanical adjustments aside, the Silver Arrows carried out some intriguing aerodynamic tests, too. On Friday the underside of the rear wing’s top flap featured a horizontal zig-zag strip of tape, with the tip of each ‘tooth’ facing the leading edge. In the aerospace industry this is known as a turbulator tape, generating tiny vortices to reduce the size of the boundary layer at such a high angle of attack.
It is actually illegal to use the tape under race circumstances, so it’s interesting to see the team use it so late in the season. Perhaps they are assessing the effects of narrowing the boundary layer with a future development in mind, maybe something along the lines of McLaren’s ‘tubercles’ flap from last year.
Given that so much fuss was made at the start of the season about noses, it was of complete surprise to see that Lotus had brought a brand new one to Abu Dhabi. The new version features the thumb tip extension we have got used to seeing from the likes of Williams and Red Bull, although not to quite the same aggression.
It is slightly higher than the original, however, freeing up room eitherside of the extension for more airflow to pass underneath and onto the splitter region. The team – in probably their last outing in the guise of Lotus before rebranding as Renault – only assessed the new nose on Friday before reverting back to the lower specification for the rest of the weekend. The regulations around the design of the nose remain static for next year, so this was undoubtedly a data gathering exercise to provide a better understanding of the development of their 2016 car.
A small guide vane was also evident at the top of the nose, perhaps providing a hint of a Brawn-style vane lining the sides of the front bulkhead/nose box.
There were also some subtle tweaks to the front wing, such as the reprofiled cascade winglet flaps and extending the last element of the wing down to the footplate rather than undercutting itself.
With changes made to the Interlagos circuit’s kerbs (now 50mm higher in places) and the track conditions affected by the weather conditions last year, Pirelli’s pre-race assessment suggested a substantial drop in laptime. This laptime deficit turned out to be over a second over 2014, with Nico Rosberg’s average speed through turns one and two being 15kph slower on his pole lap than the previous year emphasising the alterations on track.
Whilst this will have required some rethinking on the mechanical side of the setup, aero also has a key role in Brazil. Although the altitude of roughly 800m above sea level is a far cry from that of Mexico a few weeks’ ago, it still has a significant impact on the aerodynamic levels of the car and the performance of the power units.
This has meant that the teams have changed a few items on the car despite it being the latter stages of the season. We also got to see the performance of Renault’s “upgraded” power unit (you will understand why I quote that later) and Mercedes had an intriguing test device on show. Let’s find out more on this now…
As the season begins to draw to a close, it becomes more obvious that the teams’ attentions have been diverted to 2016. Whilst this means that there are fewer developments added to the current cars, there are often experimental components that are run to assess how the design of next year’s car is coming along.
Mercedes are the first to provide clues as to what is in store on the W07, by trialing what appeared to be an S-duct during free practice on Friday.
The S-duct was pioneered by Sauber in 2013 when stepped noses were in use and has since been copied by Red Bull, McLaren and Force India. Toro Rosso have also briefly used a version of their own, too.
Its purpose is to channel airflow from beneath the chassis up to the top side and over the top of the front bulkhead through an ‘s’ shaped duct. It makes use of slightly slower boundary layer flow beneath the car, exiting into generally untidy air and keeping flow attached to the top of the car. The device allows for more extreme nose designs, which is why they are not necessarily a bolt-on performance part – they act as a link between different aero structures around the centreline at the front of the car.
On closer inspection, however, it appears as if Mercedes were testing a dummy of the duct’s exit on top of the car, rather than a full duct assembly. As you can see in the illustration above, they have simply replaced the conventional panel that covers the inboard front suspension elements for one with an rearward facing duct and two interesting bulges eitherside.
Both drivers used the panel on Friday, with Rosberg’s duct taped up and Lewis Hamilton’s open.
There are a few intriguing details about this test that leave us questioning the direction they are taking with the device.
The bulges are positioned right above where the heave spring peeps out above the monocoque but, on the W06, the spring is sunk far enough into the chassis to not require any blisters in the bodywork above. This suggests that Mercedes are considering changing the suspension geometry for 2016 which would require a higher heave element position.
There was rumour that Hamilton ran a revised suspension layout in FP1, but these are not confirmed reports, so the team may have wanted to test the aero effect of a new suspension design.
Mercedes did indeed use flo-vis paint along the nose and the top of the chassis to investigate but considering that the duct wasn’t a fully operating assembly, we are left wondering as to what the purpose of doing it was.
My guess is that they are isolating the duct from the rest of the car to make sure that its introduction will not have a negative influence on the overall aerodynamics.
It is also worth noting that there was no obvious inlet at the bottom of car to provide air to any potential system they could be producing. However there is a very good explanation for this as Matt (SomersF1) has highlighted brilliantly in his blog post on the subject.
Unlike most teams on the grid, there are no visual signs that Mercedes have a driver cooling slot at the front of the car. There are, though, a few clues that suggest they do have an inlet hole in the underside of the nose, although sometimes an additional inlet is added on top of the car for hotter locations. This hole leads to a thin slot along the bottom of the front bulkhead which is visible when the nose of the car is off, before passing into the footwell of the cockpit.
Conventional S-ducts involve using a duct that covers over some of the internals in the front bulkhead, including things like the brake fluid reservoirs. This compromises the position of the duct’s exit point, which is often well ahead of the top flat surface of the chassis and instead along the upward curve from the nose backwards (defined by the regulations).
Mercedes could utilise their current driver cooling inlet by manufacturing an internal duct that exits through the aperture made for the heave spring, which coincidentally appears to be where the test panel’s duct exit begins. This allows the exit of the duct to sit nicely on top of the car, with air exiting in parallel to the chassis’ surface.
A drawback in doing such would be that air is passing around the heave spring and creating some turbulence, although it is difficult to judge how that would affect the duct’s performance.
I am sure we will get more details on it if it reappears before the year closes.
Although it has been ready since the US grand prix, it is only until now that Red Bull have opted to debut Renault’s new power unit in Brazil. It turns out the original token expenditure of 11 out of 12 is incorrect, instead the a partial upgrade of just 7 tokens was used. These were used solely on the combustion section of the engine, focusing on power output, driveability and fuel efficiency.
The remaining four are expected to be aimed at the turbocharger. This upgrade could not be introduced because of part availability and further changes needed to the exhaust system to make the upgrade work in unison. It is unclear whether Red Bull will want to use the full upgrade in Abu Dhabi, but considering that their ‘partnership’ with Renault is set to continue into 2016 I wouldn’t see a reason not to. Renault will also be quite keen to see how it performs on track, too.
Initially there was talk of a 0.1-0.2s laptime gain, but Daniel Ricciardo was in fact 7kph slower down the main straight than teammate Daniil Kvyat (who used the older spec unit). Whilst this seems a bit shocking at first, it would be unfair to say the upgrade has been a failure (yet). The final developments need to come through and the data analysed to fine-tune them in order to obtain a full assessment of Renault’s progress, but for now it doesn’t look great!
The Faenza-based team fancy their chances of grabbing sixth in the Constructors’ championship ahead of Lotus, as they sit just 9 points behind. Both drivers – Max Verstappen in particular – have hit good form and the STR10 certainly has the pace to match (barring straightline speed, of course).
To counter this deficit, Toro Rosso introduced yet another iteration of their rear wing by modifying the top flaps to reduce drag. Like Mercedes have done in the previous few seasons, the outer edges have been rounded down as they meet the endplate, reducing the angle of attack of the flap and decreasing the size of the wingtip vortices formed as result.
In all honesty I didn’t expect to be writing this piece at all, but thankfully the teams provided us this week! Even though we are heading into the latter stages of the season, and despite the distance between Europe – where all of the teams are based – and the US, the developments keep on coming through. Most of the paddock will be looking ahead to 2016 and the upgrades seen in Texas provide a few clues to what we could see next year.
However with no proper dry running (aside from the latter stages of the race, which wasn’t exactly bone dry) it would have been difficult to evaluate the these components, so expect those who brought developments to fully utilise any dry running in Mexico this weekend. Continue reading
Been crazy busy at university at the moment so unfortunately – whilst I tried to find time to write this exclusively for my blog – I’ve had to copy most of it over from my analysis piece I did for Richland F1. Quick update on YouTube things: very close to getting more videos out… 🙂
The Sochi circuit in Russia is a track of compromise – one of the longest straights on the year kicks the lap off, whilst the high speed S2 and technical final sector make for an aerodynamic headache. This sort of layout shows who has really done their homework and provides us the best chance of seeing the most efficient cars.
With not many more ideal opportunities to introduce new developments to the cars in 2015, Russia saw a number of various upgrades ranging from McLaren’s further revised power unit to an interesting tweak to the Mercedes front wing. Continue reading