Toro Rosso have fitted a new nose cone on their STR9 on Saturday at Bahrain, the penultimate day of testing before the Australian Grand Prix.
It was always a bit odd to see two bulges on each side of the chassis and at the front bulkhead with the detachable nose cone then featuring an entirely flat upper profile. The new design however explains why the bulges were there, as the team now have a nose that features two high arches on each side of the "finger" extension. The arches are the result of further attempts to get more air underneath the nose and as such feed more airflow under the car and through the rear diffuser.
Formula One car development blog
Toro Rosso have fitted a new nose cone on their STR9 on Saturday at Bahrain, the penultimate day of testing before the Australian Grand Prix.
Williams have enjoyed several extremely productive testing days so far, and with the end of the tests nearing, the team is applying and testing new aerodynamic parts. One of the bigger upgrades fitted on the FW36 on Thursday with Bottas and Friday with Massa is the new rear bodywork featuring wider sidepod exits and a central funnel that blows hot sidepod air around the exhaust.
The team switched bodywork throughout the day for both drivers to be able to evaluate the new parts properly. It does not appear like Williams had to add more cooling as the car ran fairly reliably before the change of bodywork, but possibly they are simply anticipating races with high ambient temperatures.
It's interesting to see how the new bodywork has wider sidepod outlets and lacks a carbon cover over the exhaust pipe. Also note how Williams' rear wing lacks a central support, instead featuring endplates that extend down onto the diffuser to provide support.
Attempting to further close loopholes in the regulations, the FIA have removed the possibility for teams to gain a substantial aerodynamic benefit from the starter motor hole in the diffuser. A first regulation change in this area was implemented back in 2010 after teams started to create unusually shaped starters, allowing them to make a larger starter hole in the diffuser, and thereby extract more performance from it. Back then, the FIA stepped in, allowing the hole to be no larger than 3500mm². Any other part of the diffuser had to be a continuous shape, a result of the earlier ban on double diffusers.
It has now become clear that further measures were taken by scrapping the starter hole completely, requiring teams to either design a flap in the diffuser that would close itself, or otherwise leave an opening that is not visible from underneath the car or further than 350mm behind the rear wheel centre line. Clearly, most teams have gone for a flap, often metallic, as in Williams' case, enabling the starter engine to still reach the gearbox while complying with the rules in all other situations.
Mercedes on the other hand opted to create a U-shape in the centre of the diffuser. Obviously this still allows airflow through this gap and enhance the diffuser, but the effect is likely to be much less interesting than with the start holes of 2013 and before. In fact, the central starter hole was one of the main reasons why Red Bull's Adrian Newey designed tunnels underneath the RB9's exhaust ramps, as the ramps would otherwise block airflow towards the critical central part of the diffuser.
Note: even though there used to be a regulation proposal to enable F1 cars to start themselves by using the electrical energy stored in the ERS system, the rule was later dropped, requiring the use of a starter motor that brings the crankshaft up to speed before firing up the engine.
Having enjoyed a reliable test Jerez, Mercedes have begun varying aerodynamic parts and verify performance, rather than only reliability. Mercedes appear to have had a very close look at Red Bull's rear end packaging during its few outings at Jerez as the team have introduced new bodywork around the exhaust.
Until noon, the F1 W05 was seen with the same spec as in Jerez, with narrow bodywork around the central exhaust and large oval cooling outlets on each side of the gearbox. The new bodywork as in the lower part of the image shows how more air is now exited around the exhaust, allowing for a cleaner flow lower down to the floor. The solution is far away from the layout of the Red Bull, but the inspiration of Red Bull's central funnel, also seen on the RB9 is obvious.
McLaren have come up with the first real innovation of the year by creating rear suspension wishbones that are very different to what we usually see. It is the normal approach to have a horizontal teardrop design, almost parallel to the reference plane in order to minimize drag created by the suspension elements. McLaren's version though as just a bit different.
The team's approach is far away from drag reduction. Instead, the elements are rather big with a cross section similar to a mushroom lying down on its side. Before we see how it works, it needs to be noted that the design has already been cleared as legal by the FIA. This means that the entire shape is structural, as otherwise the thick fairing would be considered as banned moving bodywork as per Article 10.3.4 of the Technical Regulations.
Article 10.3.1 further stipulate limitations to the cross section of the suspension arms, saying its longest dimension (main axis) may not be move than 100mm, and this axis can only be up to 5° off from being parallel to the reference plane. On top of that, the section must also be parallel among its main axis.
So, what McLaren have done is create a wishbone in the shape of a bell on its side. Its length is likely to be very close or exactly 100mm, while the height looks to be of similar dimension. This means the section has an aspect ration of close to 1:1, much less than the maximum allowed 3.5:1, therefore making the entire part legal.
To make it aerodynamically more interesting, the axis is then rotated by 5 degrees, so that the backside of the bell pulls air upwards, instead of being aerodynamically neutral. Each mushroom arm - here the lower rear wishbone and the trackrod - in itself generates a stagnation point ahead of the vertical flap, working like a gurney flap and creating a vortex behind it.
The gap between both arms will also do the same thing, hence the vortex flow behind it may induce upwash on the diffuser and possibly increase the mass flow out of the diffuser. It is important to note though that the entire system only works because the flow is constrained between the endplates and the rear wing on the top. So increased mass flow in there. And between the endplate and diffuser at the bottom.
Combining the two arms means that this is a double beam wing, albeit obviously a lot less efficient than a normal beam wing due to the limitations in the regulations.
Combined with an extra wing profile mounted closely above the floor, just ahead of the diffuser, this creates an upwash that helps reduce the pressure behind the suspension, helping the diffuser to extract air from under the floor. Theoretically this should help the diffuser work in a wider range and work in conjunction with the rear wing.
Importantly, McLaren have designed their rear suspension so that these rear wishbones are as much to the back as possible, attaching to the very rear of the gearbox housing. The taem have therefore also been unable to combine the driveshaft with the lower wishbones like Red Bull and Ferrari have done. It is exactly this suspension geometry that would make it extremely hard for other teams to simply copy the design, as it would require redesigning the gearbox, the rear suspension mountings and the suspension wishbones, creating a combined impact on aerodynamics and mechanical behaviour that will take time to verify and optimise.
The actual name is still up for discussion as, according to Sam Michael, the team do not have a name themselves. Seen from the rear however, McLaren's very intriguing rear suspension appears to be similar to a butterfly, with the rear crash structure being the body and the four rear wishbones forming the wing elements.
Note: the aerodynamic purpose has been determined after consulting several racecar aerodynamicists that have all converged to a similar theory.
For an overview of the entire McLaren MP4-29, check out the technical analysis.
Scuderia Ferrari have introduced another part to their F138, namely a new sidepod panel with a small bridge bending over the sidepod shoulder. The item was previously tested during free practice sessions, but before the Brazilian Grand Prix weekend never made it past Friday evening. At Autodromo Carlos Pace however, both cars had the new element fitted during qualifying, hence they will also be used during tomorrow's Grand Prix.
The item is designed to better control airflow over the sidepod in an attempt to enhance the way the coanda exhaust works. The two vertical vanes that sit underneath the bridge to connect the panel to the sidepod itself are directing air slightly outward, possibly in trying to get slightly more air around the shoulder and towards the sides of the sidepod.
Contrary to many other vertical fins that can seen on McLaren for instance, Ferrari's element is not designed to create vortices, as the bridge acts as endplates for theirs, something that is specifically designed to reduce vortices coming off the tips of winglets.
Also note, as marked by the arrow, the little camera that Ferrari uses on the sidepod panel. This is a heat camera used to monitor the front tyre's temperature, similar to Mercedes AMG's cameras fitted on the front wings.
Even though it's been known for a while, recent thermal imagery has shown the true effects of rim coatings to manage tyre temperatures. The coatings were first photographed on Mercedes AMG's Advanti wheels, featuring dimples on the inside of the rim as well (inset). Later on, Red Bull was confirmed to also use a similar treatment of their OZ Racing wheels, although in their case the inside of the wheels features grooves rather than dimples. Ferrari meanwhile are said to be coating their OZ Racing wheels as well.
It was recently also found out that the black coating is actually Polysil, produced by Nanoprom near Sassuola, Italy. It is a solvent based product containing polymers of silicium, mainly designed to protect all sorts of materials against surface friction. The product is typically sprayed to create a film of only a few microns to reach hardnesses of up to 9H. This is achieved mainly by letting the product fill up tiny gaps in the imperfect wheel surface, creating a very smooth result that may also help to reduce turbulence within the wheel.
Its black colour however is interesting for teams as that will help for the rim to absorb heat from the brakes into the Magnesium alloy wheel itself. As the rim itself has a very high thermal conductivity, the heat going into the metal is then spread rapidly throughout its entire body and partially transferred into the tyre through the tyre bead. As a result, it is possible for teams to keep the tyres at a more constant temperature, reducing the rapid drop of temperature of the tyres when running on long straights. Instead, with the rim properly warmed up, the tyre wall is kept warm, preventing the tyre's thread to cool off too quickly. The net result is more grip at turn-in as the tyres haven't cooled down as much as without the treatment.
The thermal images in the inset show how this works brilliantly for Red Bull Racing. All three are shots from an onboard camera on Sebastian Vettel's car at Circuit of the Americas during Q1 at the US Grand Prix. The first is taken on approach to turn 19, the second shows the turn-in point on turn 19, and the one below shows him at the end of the pit straight, before braking. It is evident that in all three images, the rim is relatively warm, and that by the end of the straight, the tyres are still lighting up across the entire thread's width. Similar images from Mercedes AMG show similar, but less pronounced effects, while on the Ferrari the wheel was not marked as hot by the thermal camera, indicating a lower temperature than with the other teams.
Even though it is still early days and nobody knows yet what will be the operating temperatures of the new 'conservative' Pirelli tyres, it is nonetheless very likely that this technology will continue to be used in 2014. Even more so, with Nanoprom citing the possibility to use their coatings on composites and aluminium, it is nearly sure that it is or will be used on parts of the engine as well.
Williams started the Abu Dhabi weekend by fitting Pastor Maldonado's FW35 with a non-coanda exhaust configuration, trying to do some testing for 2014 where such an exhaust will be entirely banned. Even though the exhaust positions are not quite what it will have to be in 2014- where a single exhaust pipe in the centre of the car will be mandatory - , the team hoped that be removing the exhaust channel (inset) they would get more consistent readings that are not that much influenced by the exhaust flow.
While Valtteri Bottas was also trying some 2014 parts, the team and Pastor found such improvements in the package without Coanda exhaust that the team decided to fit both cars with this package for the remainder of the weekend.
The results do pose a few questions on what is really going on at Williams. It's also not clear whether the test at Abu Dhabi are the result of Pat Symonds' influence to the team, but at least now the team appears to have accidentally stumbled on one of the major culprits of their troubled FW35.
The thing is that Williams have never been able to get the Coanda exhaust perfectly right, and they have never denied it either. At the final pre-season test of the season, in March this year at Barcelona, the team also came up with a ramp style exhaust similar to Red Bull and Lotus. However, the team found it wasn't working as expected, forcing a return to the McLaren style Coanda exhaust. Strangely however, this had worked well for McLaren in 2012, but Williams failed to get it working entirely as predicted in the wind tunnel, suggesting that the team is currently struggling with wind tunnel to track correlation, as was Ferrari last year.
It's been well documented that the Coanda exhaust is difficult to simulate in a windtunnel, as the flow is generated by the engine, acting as a very powerful air pump pushing out hot gases. Pumping air through pipes within the wind tunnel model is difficult enough already, leaving alone that this air needs to be heated. If you consider that F1 wind tunnels are all closed circuit systems, a hot exhaust flow would increase overall air temperature within the tunnel very soon, making further tests impossible until the tunnel is cooled down again.
This complexity is exactly why many teams were seen on-track running pitot tube arrays and heat cameras looking to this area of the car in an attempt to really understand where the exhaust flow is going.
Essentially for Williams, it's obviously a good thing that they now found an important reason for their car's current performance, but whether this is reassuring for their ongoing development is another question.
McLaren continue to add small updates to its car, possibly evaluating the effect of items with 2014 in mind. Already seen in Korea, the front wing had new pillars, moved back considerably. In fact the entire middle part of the front wing is new, along with the positions of the camera in between the pillars. Moving them backward meant that the team can better exploit the venturi effect that is being created by the long pillars, a feature that is rather common today in F1, as is the low down position of the camera housings.
On the sidepods the team added another turning vane, directing air outboard. The exact effects of this can be discussed about, but the vanes will certainly draw some air away from the cockpit area while each tip will induce a small vortex along the top of the sidepod, helping to energise the flow around the exhausts.
Since the introduction of Formula One's new thermal camera images, there has been talk about the relevancy of the images, leaving apart the obvious coolness that is associated with it. It is for sure that such imaging will help people understand the complex nature of Formula One, and increase the technical interest in the sport.
Before going into what we've been seeing, one needs to take into account that the images are not meant to give away technical details that other teams could use. Instead, their calibration is not made public, making it unclear when an area is considered hot enough by the camera to be visualised as blue, purple, red, yellow or white. It is even possible that this calibration is not linear either, making it even less useful from a technical perspective. Nonetheless, the new images are worth a look, as they do certainly show a few things that were known before, but not actually visible.
At the Italian Grand Prix in Monza, FOM repeatedly showed images of the front wheels on Paul Di Resta's car. There it was clear that the sidewalls are considerably cooler than the thread, while the car's negative camber setting - a common feature in racecar setup - made sure the inside of the front tyres take the main load when the car is running in a straight line. When cornering, it is obvious how this camber setting works, as the roll of the car offsets this camber on the the outer front tyre - the one that takes the biggest load - making its thread heat up evenly across the entire width.
Now at the Singapore Grand Prix, Felipe Massa's Ferrari featured a rearward looking camera, showing how the rear tyres heat up and cool down during the course of a lap. That image showed that the rear tyres are heating up mostly during acceleration, and to a little less extent under braking. This is of course easily explained by the weight transfer of the car, as under braking, the weight shifts forward, hence also why the brake balance is set up so that more brake pressure is applied to the front wheels.
In addition, it's also clear that there is less or no camber on the rear wheels, as they have to work at their best on a straight line as well. Any minor camber angle however is easily offset by the downforce on the rear wheels, pushing the entire thread onto the tarmac under acceleration.
One final, and perhaps the most interesting observation we can make, is how the inner wall of the rear tyre is heating up. It is clear that this is mostly due to the Coanda exhausts that direct the hot stream of exhaust gases down onto the car's floor, passing alongside the tyre. This considerably heats up the rear tyres and has been a particular problem for some teams to keep under control. Mercedes AMG for instance reverted to their traditional exhaust during 2012 after finding out that their tried Coanda exhaust layout worsened rear tyre wear.
In the below clip, you will also clearly see how the tyre wall is hotter when the car is accelerating hard - due to the high RPM of the engine and hence the more powerful exhaust stream. Also look at the behaviour under braking, where downshifts are followed by a short increase in rear tyre wall temperature, again due to the increase of engine revolutions. All this of course is influenced by engine mappings, but as most teams now have a good understanding of the tyres, it's unlikely anyone is using less afterburn than possible to preserve the tyres.
Note that the only time the sidewalls of the front tyres were seen coloured, and thus relatively warm, was when cars left the pits, hence with the tyres still warmed up by the blankets.