2015 Spanish GP Tech Highlights

Note: This is essentially my analysis piece for Richland F1, with some added bits and pieces, illustrations and details about the fuel flow monitoring changes that were introduced. Exam season is in full swing so apologies for the not-so-exclusive content this week.

Barcelona is pretty much the best playground for an F1 car. Aerodynamics are severely tested with a variety of long, high and medium speed corners spaced out by a series of straights, whilst the final sector is now a good hunting ground for those with strong mechanical grip after the circuit layout changed in 2008.

With such an emphasis on aero, updates are often developed from around the end of the winter testing period specifically for this race and on into the middle of the season. Teams recognise this as an opportunity to jump ahead of their nearest rival but with almost everyone making gains all of the time, eking out that extra tenth of a second from the overall package is all the more crucial.

Ferrari

Whilst the Scuderia are not quite title contenders just yet, their latest batch of developments suggests that the new-look Ferrari means business. A total of 16 new items made their way onto the SF15-T across the weekend, with Sebastian Vettel electing to run most of the them whilst teammate Kimi Raikkonen reverted to the Bahrain specification parts from Saturday onwards.

© theWPTformula

The most visual updates were the sidepods and the area in front of the radiator intakes.

Ferrari have taken advantage of their unique, angled radiator placement by creating an aggressively shaped sidepod, cutting the outer shoulder downwards and inwards. Such is the extent of the shrink-wrapping, the new bodywork has a small dimple to clear the side impact protection structure.

This creates a stepped surface where the revised vertical turning vane can now bend down and attach to. This is accompanied by a twisted cockpit-mounted vane, flicking up at the end to vorticise flow over the stepped region and achieve better attachment.

As the sidepods reach towards the back of the car, the stepped profile smooths fluidly into a re-shaped outlet which now sits a bit higher, freeing up space around the central section of the diffuser.

Upstream a number of changes have been made to maximise the radical new bodywork. The bargeboards feature a new vertical slot to increase the energy of airflow passing through the sidepod undercut, whilst the front brake ducts have had numerous revisions made to both the vanes hanging inboard of the wheel and also the bodywork that forms the ‘cake tins’ of the front hub assembly.

Towards the rear and there are more complimentary modifications. The floor area ahead of the rear tyre has three additional cuts made in front of the larger L-shaped slot to help disperse rear tyre wake from the outer wall of the diffuser. Even the top of the diffuser itself has a tiny winglet-shaped Gurney tab arrangement added to induce a little extra rear downforce.

The rear wing endplates received a subtle change to the two slots directly beneath the main plane, both increased in size to improve the efficiency of the wing at high speed.

Overall these widespread changes still didn’t move them any closer to Mercedes, as the Silver Arrows also had updates of their own. Clearly the current organisation at Ferrari is working at a higher level than previously, though, as – despite the challenges of making such dramatic changes work in unison – the updates remained on at least one car for the entire weekend.

Mercedes

Having moved forward their Barcelona developments to China two rounds ago, there were only a few minimal changes visible on the W06 in Spain.

However these detail updates will help link the larger parts together. Judging by the fact that Mercedes were still some 0.777s ahead of the next best car, this only justifies their purpose.

Small tweaks were visible on the front brake ducts to further manage front tyre wake. A small twisted vane now branches from above the top of the duct to vorticise flow behind the tyre and offset it from the sidepod shoulder behind.

A neat inlet was made into the very bottom of the sidepod along the side of the car, taking advantage of the high energy flow in this region to cool some internals near the rear end. Of course, tapping some of this flow off could well be beneficial to how they want to control air over the top of the diffuser, rather than just a simple cooling solution.

A total of four curved vortex generators were added ahead of the sidepods, all of which were placed on the side of the chassis around the bargeboards. The two pairs were both above and behind the bargeboard, beneath the sidepod intake.

Vorticising airflow here energises its course around the sidepod undercut, which can also be linked to the new inlet made downstream.

Finally, the small fins on the rear crash structure have been moved upwards onto little ears to stand in freestream air above the sidepod. They appear to be achieving a small upwash effect with these devices despite removing the monkey seat winglet, which has a much greater effect than the fins. I have a few reasons as to why teams are removing the aforementioned winglet, but more on this as the season progresses.

Red Bull

We have heard that the short nose has been coming for some time, I was beginning to wonder if it was even in existence at all! Finally the RB11 received arguably one of the centrepieces of its design.

RB11 short nose

The overall aim of the short nose is to free up more space for air to pass beneath the car and there is now visibly much more volume available for this to occur.

However, because of the length of the nose, there is less space for the crash structure to absorb an impact which ultimately means that more material must be used to pass the tests. Red Bull have had to repeatedly retake the crash tests as they have had trouble keeping the weight down whilst being within the regulations, hence its delayed arrival.

Described by Christian Horner as an “engineering masterpiece”, you can see why it took so long to produce.

It is incredibly short, with the thumb-shaped stub lying as far back within the regulations as possible. The front wing mounting pylons now lean back at a slack angle, with their trailing edges extending both backwards and inwards to form a twisted profile which will aid airflow along the centreline of the car.

Williams

Williams have produced a bit of a turn in performance this weekend, which can be put down to two things: a few upgrades and a better understanding of the tyres. It’s all well and good having a car that produces lots of downforce but if the tyres are not (consistently) in the right operating window that is basically rendered useless. Afterall, the rubber is the only thing that connects the car to the track.

Development-wise a variety of detail adjustments were made across the board but the most note-worthy came in the form of the airflow conditioning devices around the cockpit area.

The number of vortex generators that now align the top of the sidepod have tripled and are now accompanied by a new single horizontal strake along the side of the chassis. These will collectively manage airflow over the sidepod and direct it towards the floor, preventing stagnant flow building up in the process.

The vertical turning vane that stands against the outer shoulder of the sidepod has also been re-profiled slightly. It’s a subtle tweak but the it looks to collect more air from the sidepod’s leading edge and turn it round its circumference. This area is very sensitive to airflow so it is no surprise to see constant work being made to the devices here.

Mechanically, Williams made some alterations to both the suspension components and their setup. A better understanding of the tyres and how to keep them in their operating window helped them establish a small advantage over at least one of the Ferraris, showing that they can still develop alongside the big players in the sport.

Unlocking performance from the rubber’s interaction with the asphalt is a lot harder than producing more downforce, but there is more laptime in doing this. Just look at the way Mercedes climbed the ranks from 2013 to 2014 – this can be put down to a number of things, but by understanding how to stretch the Pirelli tyres out and keep them within a good temperature window was one of the key areas of improvement for them. Williams are looking for the same answers to keep them in the hunt for second place in the Constructors’ championship.

McLaren

It may be described as “dynamic” and “predatory”, but beyond the PR drivel there is a good reason as to why McLaren have opted to switch up their livery.

The new colour scheme has saved the MP4-30 over 1kg of mass over the previous design as the pigments used to produce the predominately chrome look beforehand weighed that a tiny bit extra than those used to make graphite. A small gain but a gain nonetheless.

Honda also brought a number of revisions without having to spend any of their 10 remaining power unit tokens. The beautifully crafted aluminium inlet plenum has now been replaced by a more conventional carbon fibre version to further reduce weight, and a number of seals have been redesigned to improve reliability.

Driveability has also been attended to, with a significant software update allowing better control of the power unit under acceleration and braking events.

These changes, combined with ExxonMobil’s new fuel mixture, have resulted in a solid step forward for McLaren in Spain, as proven by both cars reaching Q2 on Saturday. Both chassis and power unit still aren’t quite there but the signs are promising.

Also, McLaren swapped its aerofoil-shaped lower rear wishbone in favour of a thin, tubular design. This further negates any interaction with the diffuser like they were doing last year, by essentially removing any aerodynamic influence that the suspension member may have had previously. Expect the unique layout to be dropped entirely next year for something more conventional.

Toro Rosso

A detail change was made to the leading edge of the STR10’s splitter, by extending the vertical vane upwards and then splitting it into three. The individual vanes aim to turn high velocity flow along the bargeboard area and through the sidepod undercut. This is beneficial for both feeding the top surface of the diffuser further back and for improving the consistency of the Y250 vortex that runs in parallel with this section of floor.

Fuel flow monitoring clamp-down

Since the introduction of the current power unit regulations, teams have been limited to a fuel flow limit of 100kg per hour. The car can only carry 100kg of fuel from the start of the race so as a result we see fuel saving strategies deployed.

However the development race within the fuel world is just as ferocious as that within the teams, with Shell, Petronas, Petrobras and ExxonMobil constantly formulating new mixtures to eke more power from every drop of fuel.

As a result pretty much every team is able to start the race with under 100kg of fuel, which improves laptime during the early stages.

Given these circumstances you would wonder how anyone could exploit anything beyond 100kg/h without running out of fuel, yet this is precisely what the FIA believe some teams are doing at some periods in the race to increase power output.

The fuel flow sensor is currently positioned between the tank and the fuel collector. It is then pumped up to the fuel rail, through the injectors and into the cylinders. The FIA suspects that some teams are feeding the injectors fuel at a faster rate once it passes the sensor, which can quite easily be done by pumping the fuel from the collector at a higher pressure.

In the FIA’s technical directive sent to the teams it also stated that the flow rate must “remain constant above a flow rate of 90kg/hr”, suggesting that some teams are also able to slow the flow rate within the low pressure systems and save fuel as a result.

It’s an intriguing battleground and one that we should watch more closely in the coming races.

2015 Bahrain GP Tech Highlights

Given that the gap between the Chinese and Bahrain grand prix was just one, tweaks to the cars were minimal and were mainly aimed at cooling as the two circuits share quite similar downforce characteristics.

However more was learnt about McLaren’s Honda power unit plus a few other additions were also visible over the course of the weekend.

McLaren (Quoted is from my piece for Richland F1)

“A lot has been disputed about the underlying technical details of Honda’s 2015 powertrain. What we have already established is that they are indeed utilising the split turbo concept that Mercedes pioneered last year, with the exhaust driven turbine and the compressor being separated by the MGU-H that sits in the V of the engine.

However, information remained scarce for some time as to how they were cooling the compressed air until the beginning of April, when it was revealed that McLaren run an air-to-air intercooler in the right-hand sidepod. This therefore meant that the radiator – uniquely placed above the engine itself and fed by the top inlet in the airbox – is used to cool the ERS package. This opened up space to pinch the bodywork inwards, tapering tightly into the “size zero” Coke-bottle region at the back of the car.

Recently, more details have been uncovered about just what McLaren are doing with their power unit to allow such tight packaging with relatively little cooling requirements. Although they are still running quite a large central outlet at the back, the overall area of openings made into the car is pretty minimal relative to the rest of the grid.

mp4-30+PUupdate

It transpires that Honda have developed a totally different compressor side to the turbo than any other manufacturer. The regulations do govern this area quite strictly which is why Mercedes, Ferrari and Renault have all converged on the same solution. Honda on the other hand have been a bit different.

The rules state that the compressor must consist of only a single stage, so the general consensus is to use a large centrifugal fan to draw air in through the airbox and onto the intercooler. The larger the fan the higher the boost pressure achieved although this is not such a big tradeoff when considering the fuel flow limit. A smaller fan, though, will spool much faster due to its lower inertia, which improves drivability.

Honda have opted to use a much smaller, axial compressor but without the multiple fan elements that would make the system illegal. Instead there is one elongated fan that stretches across a narrow tube, with perhaps a multitude of increasingly sized blades to guide air through.

There are a number of advantages in doing this: the resulting smaller compressor can be packaged neatly into the V of the engine alongside the MGU-H, removing the blockage created by a large centrifugal fan and bumping the engine up closer to the fuel tank. The emphasis on doing this is to again create more space further behind and improve the weight distribution of the car.

Secondly, a smaller fan naturally spools much faster which places less reliance on the MGU-H to generate boost under acceleration so energy can be saved instead for the MGU-K – a more dominant player in terms of laptime and an area in which Honda have struggled to make inroads in so far. Once reliability problems are sorted in this area we could see the partnership making large strides in energy recovery and deployment later in the year.

To make room for the top mounted radiator, Honda have had to create a low-lying inlet plenum which is made from aluminium rather than carbon fibre. This will have been done to resist the transfer of heat from the radiator above and also to make a more suitable shape in a crowded area. With the introduction of variable-length inlet trumpets, I imagine that this was a pretty tough component to produce.

Overall, it is these detailed changes that Honda have implemented that will eventually aid McLaren’s aerodynamic package. Once the MGU-K seal gremlins have been overcome and the power output rises further, only then will we see the true potential of the MP4-30 chassis.”

Another possible theory is the use of Honeywell’s DualBoost turbocharger, which is technically a type of axial compressor. It also utilises two inlet pipes for the compressor, with the exhaust-driven turbine spooling two fans that face back-to-back of eachother before combining the charge air into one pipe to be fed onto the intercooler. It’s a smaller solution than a conventional centrifugal fan thanks to the dual fans, so it could squeeze into the V of the engine.

Aside from the power unit, the MP4-30 featured some small aerodynamic adjustments.

Gone is the innovative ‘tubercles’ rear wing upper flap and in its place is a traditional straight-cut leading edge. The idea behind the tubercles flap was to improve flow attachment as the DRS closed (more on this here) but clearly – with a host of new faces within the McLaren aerodynamic – there has been a change of philosophy and perhaps some subtle detail work done elsewhere to improve efficiency in this scenario.

Modifications were also made to the rear diffuser. As well as upwash, the diffuser’s outer walls expand airflow out from beneath the floor, too, to suck the car further into the ground. McLaren have tweaked this area to improve this effect, which has also resulted in reducing the number of fences from three to two.

Red Bull

RB11 FW

After introducing a new front wing in China, another small tweak was made to the endplate in Bahrain.

The red line represents the China update, with the arched section now more pronounced than before and pushed slightly inboard than the previous specification. The old wing’s arch was pushed right up against the endplate, so this change in philosophy follows more of a Mercedes pathway.

Highlighted is the new addition – a small pressure gradient vane that has become pretty common on the cars this year. The vane will cause a small low pressure zone behind, drawing air out from behind both the underside of the wing and from behind the endplate at a faster rate. This is another outwash aid which, combined with the blown front axle and the underbody effect of the wing, should help improve flow management around the front tyre.

2015 Chinese GP Tech Highlights

Note: Due to a lack of time (as explained in my Announcements 5 blog post) most of this has been copied off my analysis piece for Richland F1, with some added extras that I worth noting.

Shanghai is a bit of a tricky track to set the car up for as the corners are predominantly medium speed with long traction zones (especially the large banked turn onto the huge back straight), but there are plenty of straights to make up time on.

It is for these reasons that we tend to see a compromised aerodynamic package which will later be seen in races such as Canada, where the trade-off between downforce and top speed is constantly being assessed throughout the weekend.

The lengthy corners also put a focus on front tyre life, particularly the front left, so you can’t take too much wing off the car or else you risk putting the tyres in jeopardy. Even if you have slightly too little downforce the tyres won’t stay in their optimum temperature because the straights cool them down before the driver even reaches the braking zone – you could say that it is one of the toughest rounds of the year regarding setup.

To solve these problems teams bring upgrades, which are ideally more efficient at producing downforce than the outgoing component.

Mercedes

As promised by Mercedes, an array of new parts made their way onto the W06 right from FP1 after being beaten by Ferrari two weeks earlier.

W06 FW China

Front wing development has stabilised slightly over the past season but this new wing has once more upped the game by introducing an even more aggressive outboard region concept.

The elements – which remain at a total of six – arch aggressively at the extremities of the wing to form two distinctive sections: the inboard and outboard. The inboard is composed of the main plane which is split into two planes, and the upper two flaps and these are responsible for creating the Y250 vortex and controlling airflow around the front suspensions members.

Outboard, Mercedes have further expanded on the vortex tunnel design by almost isolating it entirely from the rest of the wing. The leading edge of the tunnel is shaped such that the air curls over on itself and accelerates. This coupled with the introduction of higher pressure flow through the slot gaps on the upper surface of the wing coils up the air to form a powerful vortex that is shed around the front tyre. This generates a huge amount of downforce and helps the endplates push flow around the front tyre too – the outwash effect.

These vortices tend to break up once they have come around the tyre as the turbulent wake behind the rotating wheel mixes with it and disperses. Contrary to popular belief these vortices never reach the Coke-bottle section of the car – the designers want to keep this area full of clean laminar flow to work the top of the diffuser, which is why we see the large vanes the hang off the shoulder of the sidepods to protect air passing through the ‘pod’s undercut.

Additionally, more tiny vortex generators on the individual planes of the wing were also evident. Again, this is to help air pass through the slot gaps and aid how the main vortex in the tunnel forms.

Mated with the new wing was an updated pair of front brake ducts. The previous large vane that hung off the guide plane of the duct has been deleted in favour of a more fluid-looking flick-shaped vane that branches neatly from the leading edge of the duct. This will work more favourably with the updated front wing.

As mentioned above, top speed is also important in China so a revised rear wing was also brought in. The wing has a slightly lower angle of attach and the wing tips cut triangularly to reduce drag.

Red Bull

Renault’s power deficit was always going to be more evident here than any other track so far in 2015 so Red Bull had a number of rear wing options to play with. A lower angle of attack version was used by both drivers during qualifying and the race, both of which feature their more intricate endplate design with the extended slot along the leading edge.

On the front wing, the Milton Keynes outfit have now officially departed with their long-standing endplate design in favour for a Mercedes-style solution, featuring a single fence with a small flick at the trailing edge to entice flow around the front tyre.

However the most important change Red Bull have made so far this year is returning to Brembo discs and calipers from China onwards, swapping out the Hitcos used since winter testing. The team opted to use Hitco at the start of the year following Sebastian Vettel’s feedback before he headed off to Ferrari, but cooling issues have resulted in them being ditched in favour of what they has last year.

The Brembos work like no other brake on the grid – they are not the most powerful but they are extremely consistent across the braking phase. However they also require less cooling inlets and are generally easier to manage than most of the other manufacturers out there, which is why we saw the issues the team had in Malaysia.

Swapping back to another brake supplier is pretty difficult, though. Daniel Ricciardo was having visible difficulty to stop the car during the race, which can be put down to the team not finding the sweet spot between the brake bias and the pressure versus the harvesting capabilities of the MGU-K. It’s more of a setup issue than an inherent car problem, so expect it to be addressed soon.

Sauber

C34 FW

Like Mercedes, Sauber also had a front wing/front brake duct update. The new wing is a quite the departure from its predecessor as the promising C34 begins to undergo significant development.

Designed during early 2015, this wing was meant to be introduced in Bahrain but it was fast-tracked thanks to funds coming through quicker than expected.

Whilst the cascade winglet remains very much the same as the last edition, the accompanying ‘r’ vane has been moved closer with a small aerofoil join sandwiched between them.

The wing itself has been upgraded from four to five elements, with a more conventional divide between the inboard and outboard sections similar to that of Mercedes. Metal clips have been formed into the carbon fibre at the inboard region to stiffen up the wing as it undergoes load, allowing for a more consistent formation of the Y250 vortex across a range of speeds.

It is worth noting that the flap adjuster lies on the inboard section. More commonly this housing is placed on the divide between the two regions as this is more aero neutral. However keeping the outboard segment cleaner can certainly benefit the overall outwash effect of the wing and is also slightly more efficient.

Lotus

Some subtle changes were made to the Lotus front end, minutely changing the aerostructures to suit components downstream.

The nose pylons were extended downwards at their base, removing the transitional step between the pylon itself and the wing’s mounting bracket to form a smooth profile for air to pass over.

This was accompanied by a small adjustment to the inboard flap section that is responsible for controlling the Y250 vortex. These were extended further inwards and curled down towards the main plane in a similar fashion to those on the Mercedes. However this this wing configuration was not raced on Sunday although expect it to turn up in Bahrain this weekend.

Williams

For all the raving about Williams’ front wing during the weekend, it appears as if it was just a minute alteration to the under-wing turning vanes that was the only visible sight of anything new.

But do not let that fool you so quickly. So much work is done through the layup of carbon fibre that has a dramatic effect on how the wing performs across all air speeds. Williams are one team in particular who are ‘bending’ the letter of law with some extremely flexible wing flaps, as evident on the onboard nose camera shot. Getting the wing to flex in a desired manner can be worth multiple tenths of a second per lap when working correctly. Expect this to be an underlying feature of the 2015 season as the designers run out of areas to play with.

Announcements 5…

I have been generating content for this blog for just over two years now and I have already gathered a significant following. I have enjoyed, and still do enjoy, writing on here and expressing my knowledge (which increases all the time) of engineering in motorsport and I hope you also like my content.

However lately I have had to take a bit of back seat from the blog and F1 in general. You may have noticed I’ve been less active on social media as well.

I still love the sport and the technical side always excites me but I am struggling to find time to juggle a social life, earning a bit of income to pay for that social life, studying at degree level and – most importantly – finding enjoyment out of all of these things.

This all means that I have much less time to write on here. This is also due to an underlying feeling of a lack of motivation at the moment – we all go through it and hopefully I’ll be fired up again fully in the near future.

I continue to religiously watch all the races (as I have done since 2007) because at the end of the day I fell in love with F1 as a fan, not as a journalist. The same applies to all the good journalists out there because they apply emotion to their writing that others simply can’t translate.

It’s gutting because I don’t like not posting on here, I promise you that! My blog is my pride and joy and it has propelled me to places I never thought were possible in motorsport journalism and we’re just scratching the surface…

Ultimately my ambition is for other people to be writing about what I have designed on the cars and to reach that I have to prioritise things. So this is just an announcement to say that there will be less on here than normal for now as I get on top of things.

I have promised an LMP1 car comparison piece between Audi’s 2015 R18 e-tron quattro and Nissan’s intriguing GT-R LM NISMO, so I’ll get that sorted soon! But for the time being it might just be Technical Highlights posts only, plus a bit extra for Richland F1 as they are fantastic website heading in a strong direction.

I hope you appreciate this decision.

 

Silverstone Single Seater Driving Experience

RK7_1360

Not a tech related post but I thought I’d share this with you.

As some of you may know, my parents gave me a single seater driving experience at Silverstone for my 18th birthday, all the way back in 2013! Unfortunately – thanks to the miserable British weather about 90% of the time – it took me three attempts to complete the damn thing: the previous two occasions had been called off due to excessive rainfall and poor visibility. Continue reading

2015 Malaysia GP Tech Highlights

Traditionally the Malaysian GP comes just one week after the opening round in Australia. However this year a two week gap has allowed teams to fine-tune their cooling packages ahead of what is one of, if not the most challenging places to race a Formula 1 car.

Impressively, most teams managed to retain a relatively tight rear end despite track temperatures peaking at 61.4 degrees Celsius. If we compare how open the bodywork was this time last year there is clear evidence that this year’s power units are another step forward in terms of efficiency. Closing up bodywork reduces drag and allows the aerodynamics to work at their maximum potential, rather than being disrupted by hot air vents and larger outlets. Continue reading

2015 Australian GP Tech Highlights

The opening round of the season in Melbourne produced few technical upgrades, although most of what was brought to the final test session was intended for the opening races of 2015. Whilst we can expect a few more bits for Malaysia, this Technical Highlights post runs through a couple of the larger developments from the teams from the final Barcelona test and the minor detail changes made for Australia. Continue reading