Sunday March 3: no upgrade bonanza on final day
Contrary to early expectations, the final day of Formula 1 2013 winter testing didn't feature a mass roll-out of new technical innovations.
Having lost so many days with bad weather it seems the teams opted to bolt on their Melbourne spec parts on Saturday, a day early, leaving them with two clear days to refine their final set-ups ahead of Australia.
Despite that, there was still plenty of intrigue given the number of smaller tweaks teams made on the penultimate day. Most of these upgrades will be heading to Australia for the 2013 season opener.
It seems Raikkonen's luck isn't with him during testing: having lost running time to weather or technical maladies, he then suffered a stomach bug on Saturday and gearbox problems on the final day.
Indeed reliability at Lotus has been an issue, in particular the need to change two gearboxes, which will worry the team. At least it hasn't been alone in suffering problems with the new SECU.
When the E21 did run it was fitted with special exhaust covers. These were the usual shiny metal Coanda exhaust outlets, but with shrouds welded over the top of them.
Obviously illegal for a race weekend, these parts were not a challenge to the rules, merely test parts used to exclude the exhaust flow from the test results. The data was gathered in just one run and they did not appear again.
One development not visited in the Saturday tech blog was the revised front wing. Lotus is well known for running numerous iterations of front wing design and this version is a rework of the wing already tested this winter.
It still retains a four element design, but the vane on the endplate is now one piece, rather than two. There is a slot in it to help keep the flow attached to the vane's inner face.
Lotus's unusual exhaust shrouds © XPB
Lotus also installed a unique bargeboard design. Where the large board fitted in front of the sidepod is usually one piece, on the E21 it was made from four separate vanes in a single assembly.
This slotted board is probably an effort to turn the airflow outwards around the sidepods more aggressively, although the slots will also help keep the airflow attached to the board at they now sweep out more suddenly.
Updates to the RB9 prior to the final test served to underline what was apparent at its launch: this is very much an evolutionary design.
Flow-vis on the Red Bull's rear © XPB
We were expecting some new concepts to be tested in the last days at Barcelona, but surprisingly that didn't come to pass. Work on the final day focused on aero testing of the flow behind the car. In the morning the car was fitted with an array of sensors behind the diffuser and rear wing, while flow-vis tests were later carried out around the rear wing.
With the team not setting competitive times in testing and no innovations arriving, it might be easy to write off the Red Bulls early on. This would be a mistake though - the RB9 is still expected to be at least as quick as the likes of McLaren and Ferrari.
Ferrari's penultimate day ended with a dramatic car failure for Felipe Massa. Having just pitted and headed out for the final run of the day, the left front wheel parted company with the car along a short straight. There was an explosion of debris as the wheelnut and parts of the front hub broke up and the wheel flew off into the gravel. Luckily the car was brought to a safe halt by Massa.
It was confirmed by Ferrari as a front hub failure. This part is effectively the front axle. Normally it is pointed at the end to enable fast wheel changes. The pointed end also houses the retention system and threads that hold the wheel nut on.
Ferrari was evaluating the cause of Massa's dramatic wheel issue © autosport.com
Looking at this area after the crash, the hub was hollow ended, which suggests the hub failed near the wheel nut and explains the suddenness of the failure and cloud of debris.
On Sunday, before Alonso's final run of the day, the Ferrari was brought into the pitlane and idled for almost a minute in front of the pit with the team's screens hiding the car.
Luckily the car was visible from in front, revealing that Ferrari purposely loosened the wheelnut. From this picture it's clear the wheel has been offset from its normal position and the car's weight taken through the hub. The car was then wheeled back into the pit and Alonso completed a final three-lap run to end the session and the test.
I've never seen this test carried out before, but it is most likely related to the previous day's failure.
Other work today focused on the new sidepods and the car completed several runs with the floor covered in flow-vis. At the end of each of these runs the car was brought into the pit garage and the aerodynamicists took pictures of the resulting streaks.
Looking closely at the many pictures taken of the car after these tests, the huge influence the exhaust has on the flow around the diffuser area is clear.
Flow-vis gives an insight into exhaust flow © autosport.com
The exhaust is blowing on the diffuser just a few centimeters after the end of the Coanda bodywork. Another effect that is clear is the three Red Bull-like vanes fitted on top of the diffuser work very efficiently at diverging the airflow outward and behind the rear tyres.
As this is a test with all teams present, engineers will also be looking at their rivals' flow-vis results. Through the course of this test some of the results have been surprisingly bad, while others have showed more positive traits.
How much they risk from others seeing the results of their public aero test is probably limited. But this is a fascinating chance to see the aerodynamics in action.
Saturday March 2: Newey parts time
Red Bull typically waits until the last day of testing to introduce its Melbourne-specification package, but the team started the Saturday of the Barcelona test with a new front wing and revised sidepods.
Despite the rush to test the new parts, it was unusual that Red Bull completed barely more than half of the laps completed by some of its rivals today.
Red Bull's new front wing has changed largely in the way that the cascade winglet mounts to the endplate and how that is then used to turn the airflow around the front tyre.
Normally, the cascade winglet curls down slightly to join the endplate and this new cascade curves down even more. The endplate sports slots where the winglet merges into it.
This is similar to the way the front wing curls down to meet the endplate, with the slots working to keep the airflow attached as the wing curves steeply.
Red Bull introduced a new front wing © XPB
With the cascade winglet now aiding the flow around the tyre, the wing should be more efficient and less affected by the tyre behind it.
At the rear, the sidepods have been altered slightly. The bulge around the exhaust outlet is more pronounced and the shape of the tunnels formed beneath this area is also revised.
With this design now having run for 59 laps, it is unlikely the team will now run a further revised aero package in tomorrow's final day of testing.
A new simpler front wing appeared briefly yesterday and was fitted for most of today.
McLaren has slowly been moving away from its complex stepped front wing shape ever since it introduced a new version at the United States Grand Prix last year.
The stepped leading edge had been used to separate the flow passing inside the front wheel from that passing outside.
The thinking of this design was that it prevented the front tyre wake passing inwards and upsetting the wake off the front wing. But it seems ways are being found to retain the front wing performance without the complex shaping.
The new wing features a near-flat leading edge and no step is formed in line with the front tyre. The simplification goes further, in that the R-shaped vane fitted atop the wing is also removed and a vertical turning vane replaces it.
Despite the simpler wing shape, the team still uses a relatively large flap whereas most teams shape the flaps to be narrower towards the middle of the car. This reduces the wing wake's impact on bodywork along the centre of the car.
It could be concluded that McLaren's wing produces a lot of downforce due to the large amount of wing surface, which would need to be balanced by downforce at the rear of the car.
McLaren ran a simpler front wing © XPB
This suggests that McLaren is in a healthy position as far as downforce is concerned.
Another feature of the new front end is the return to turning vanes beneath the nose.
McLaren switched to the more popular curved vane sunder the front suspension by fitting a three-vane design mounted under the chassis.
Yesterday, the car ran with these reduced to just the single leading vane but today the vanes were totally removed and replaced by the nose cone-mounted versions.
This might sound like an aerodynamic solution, but the problem is more to do with access. Jenson Button has been open about the fact that the MP4-28 is still tricky to find a set-up for.
Part of the set-up process is changing front suspension settings and with its new pull-rod suspension, this requires access to the springs and dampers mounted low down inside the front of the monocoque.
Changing these has eaten up precious testing time, with 45-minute stops being the norm for the team.
These delays are exacerbating the set-up problem, as fewer runs can be completed in a day.
Removing the under-chassis vanes means they do not obstruct the mechanics' access to the springs/dampers through an access hatch under the monocoque.
Ferrari had similar issues last year when it also switched to the under-chassis vanes on its pull-rod equipped car and for 2013, improving access to the suspension was one of the design goals.
Despite having previously run with exhaust bodywork that the FIA suggested was illegal, Williams today ran with entirely different bodywork. This raises the question of why you would fit such controversial bodywork as an interim measure...
Regardless, the new sidepods follow a similar Coanda design to the fellow Renault-powered Red Bull and Lotus cars.
This is a sidepod with a ramped section of bodywork aft of the exhaust and a tunnel to aid the flow around the car getting to the diffuser.
Williams's new sidepods © XPB
With the Williams design, the sidepod shape is far simpler and the tunnel much smaller than its rivals.
The ramped section of bodywork encourages the exhaust to be directed to the edge of the diffuser using the Coanda effect.
While this is a more accurate way to direct the exhaust flow compared to the McLaren-style sidepod, it does make it harder to direct the general airflow around the car.
Red Bull struggled with this issue for much of last year until it enlarged and simplified the tunnels. Williams has not curved in the sidepod to encourage as much airflow into the 5cm tall tunnel as Red Bull does.
Driver comments at the end of the day suggest the car is better in both fast and slow turns with the new sidepods.
Friday March 1: Ferrari updates appear
Ferrari was the star attraction of the second day of the final Barcelona test as it bolted on a major update once the early rain had stopped.
Conceptually similar to the launch version, the sidepods now sweep down more steeply over the exhaust exits.
As part of this, the Coanda channel also droops to help aim the exhaust plume towards the diffuser's edge.
As the rules demand the exhaust has to point upwards by 10 degrees, teams need to bend the plume downwards to get it to seal the diffuser.
As much as the current trend in sidepod and exhaust design is labelled as 'Coanda', there are actually two aero effects at play.
The first of these effects is indeed 'Coanda', which is the tendency for the exhaust flow to stick to the curved bodywork trailing behind the exhaust. This is the same as a stream of tap water bending as it runs over the back of a spoon.
The second effect is 'downwash'. This is how the airflow over the sidepods hits the upward pointing exhaust plume and bends it downwards, just as a breeze would bend a tall tree.
These two effects are enough to dramatically alter the path of the exhaust gasses.
Ferrari revealed a major upgrade on Ferrari © XPB
With Ferrari's new sidepods, the swept shape encourages more downwash while the extended channel behind the exhaust uses the Coanda effect to further alter the exhausts' flow.
Underlining that these will be the specification used for the first four flyaway races, the sidepods also featured two outlets that were closed in the relative cold of Barcelona. These will be opened up at the hotter races, notably Malaysia, to improve cooling.
Seen briefly on just a few runs and barely captured by photographers was an entirely new front wing.
This new wing sports no fewer than seven elements at its outer tips, as well as revised endplates and cascades.
Teams increasingly seek to create most of the wing's downforce at its tips. This sends the turbulent wake harmlessly around the front wheels and leaves the inboard part of the wing sending cleaner flow over the centre of the car.
Having more elements means that the wing can curve outwards at a greater angle, creating more downforce and sending more flow around the front wheel. So Ferrari now has more elements for an even more aggressive flow.
Not only does the wing gain extra slots, but the flat plate running along the bottom of the endplate is now also split with a slot. This hasn't been seen in F1 before.
Mounted to the endplate is a new cascade arrangement. Previously this was two winglets mounted in parallel. Now there is a single winglet, but much wider and split by a vertical fence.
Another detail on the endplate has been taken from Red Bull. At the upper leading edge of the endplate a small fin has been added, this is a simple little device to create a spiralling wake to help divert flow around the front tyre.
Red Bull passive DRS
Red Bull tested its passive DRS for the first time today.
As the double DRS concept, raced by Red Bull from Singapore last year, has now been outlawed it's only such passive devices that can be used to boost top speed.
Unlike the double DRS, the passive DRS requires no external signal to switch the flow from neutral to that stalling the rear wing. It's simply the increase in speed that changes the airflow inside the ducting.
Red Bull's design is neater and noticeably similar than the other designs seen so far. The only visible part of the system is the stalling duct that exits from the engine cover and hooks up to the rear wing.
This duct will blow across the wing when near top speed to break up and stall the airflow passing under the wing.
Stalling the wing will reduce downforce and drag, resulting in an increase in top speed.
Red Bull's passive DRS broke cover © XPB
What's not visible on the system is the inlet, which might be hidden inside the roll hoop/airbox and the second outlet.
This second outlet will blow all the time at lower speeds, when the system is not stalling the rear wing.
It will need to exit into a low pressure area and this is likely to be under the beam wing or perhaps under the rear crash structure. This latter location is likely as there is an outlet exiting just above the diffuser.
This means the crash structure must have an internal duct to pass the flow from the fluid switch above the engine out over the diffuser.
This will be a very useful system to run as Red Bull's strategy tends to be to focus on strong qualifying pace and not top straightline speed in the races.
At the opposite end of the pitlane, Marussia continues to develop the MR02.
The team has used the slimmer rear bodywork and added a new nose and front wing.
Marussia remains a follower of the low nose and since Silverstone last year, has run a distinctive bump under the nose cone. This bump has now been removed and the result is a shallower nose cross section.
While all eyes were on its driver situation, Marussia was introducing significant new parts © XPB
Mated to this is a new front wing, completely different in both frontal profile and the shape of the flaps.
Akin to McLaren's dog-legged front wing leading edge, Marussia has added a step in the profile.
This makes the wing narrower and the footplate wider at the front, but allows the airflow to sweep outwards around the front tyre.
Then the flap has a new profile, with the inboard end split with a slot.
This slot is highlighted by the flow visualisation paint the team applied to correlate the real wing to windtunnel predictions.
DAY 1: FIRST GLIMPSES OF MELBOURNE
This final pre-season test at Barcelona is all about fitting Melbourne-specification parts to the cars.
The run-sheets will focus on qualifying and race simulations and far less time will be dedicated to aero mapping runs, meaning that we're likely to see low fuel load-runs and fast times before the four days are over.
Such runs might be on hold for now due to the weather, but we've already started to see Melbourne-specification parts appearing.
Renault engine maps
At the previous test another technical controversy brewed up as Red Bull and Lotus tried Renault engine mappings more than two per cent different to those they started last season with.
Renault's interpretation of engine mapping rules has been corrected by the FIA © XPB
Last year, new engine mapping rules were introduced to outlaw the off-throttle maps used to exploit blown diffusers.
After the 2012 German Grand Prix, the FIA clarified how much the mappings can change during the year, introducing the rule that they cannot vary by more the two per cent compared to the maps at the start of the season.
Renault thought the baseline map would be reset this year, but the FIA had clarified that the baseline is still the early-2012 specification. This means that Red Bull and Lotus will not have the latest mapping to exploit with their updated cars.
Another area of the rules constantly probed by teams, in particular by Red Bull, is front wing flexibility.
Late last year, it was clear Red Bull was twisting the wing backwards at speed to reduce drag on the straights.
This led to new tests that moved the scrutineering test load further back along the wing to ensure that the wing not only didn't bow, but also didn't twist.
At the RB9's launch Newey alluded to the fact that this new test is hard to pass and today's testing showed the lengths Red Bull will go to gain performance and still meet the regulations.
Red Bull used sensors to gauge front wing movement © LAT
The nose assembly was set up with sensors in the nose cameras and red dots on the endplates.
The sensors accurately measure the distance to each of these spots and work out how much the wing is moving as speed increases.
Currently, teams can flex their wings despite a ban on bodywork flexibility, provided it meets the deflection test.
Red Bull will have tested its wing on rigs at the factory and can be sure that it passes the test. Today's work was purely to ensure that the wing was flexing as predicted.
This suggests that wings teetering on the edge of the rules will be raced this year and the flexi-wing debate will continue.
With big updates still to come, Ferrari again ran strakes along the edge of the nose.
Their shape and position has been slightly adjusted and the purpose is now clearer. They are for legality purposes and therefore needed to be tested before Melbourne.
According to the rules, the nose must be a single open shape if sliced vertically. As Ferrari's nose is wide at the front and then narrows before widening again to meet the chassis, it can form two separate sections if sliced vertically at the sides.
The strake joins these two sections to form a single shape, allowing the nose to meet the letter of the law.
McLaren has simplified the curved bargeboards under the nose © XPB
McLaren introduced two horizontal vanes over the front of the sidepods at the start of testing, and while it removed them for the second test the vanes were reintroduced today.
It has also moved to simplify the curved bargeboards under the nose.
What was a three-vane device has now become one very slim vane. It's strange to simplify this area and we'll need to keep an eye on how it changes over the rest of the test.
It appears that Lotus has a rear wing airflow problem. This became apparent at the last test when, in the wet, the team detected that the direction of the airflow on the endplates was actually in reverse of how it was supposed to travel.
A camera was quickly fitted to look at the problem and more test time was dedicated to resolving the issue today. It appears the problem is at low speed and unrelated to the Drag Reduction device (DRD).
For the first time we have also seen the Lotus DRD inlets opened up - up until now these have been fitted with rounded covers. There's now the expectation that the team will devote some running later in the week to testing the device.
As the wet weather broke, Lotus needed to cover the inlets and used clear 'helicopter' tape, so despite appearances the inlets were covered for much of the day.
A solution adopted by several teams last year was the slots in the middle part of the rear wing endplate.
Toro Rosso's rear wing © XPB
These slots work much like Ferrari's new vaned endplate by improving the airflow through the wing.
Due to the regulations, the rear wing endplate is a large and relatively flat device. But the flow ahead of and behind the wing is three-dimensional. A large proportion of that flow wants to come in from the sides.
The flat endplates tend to deter this flow and rob the wing of potential downforce.
These slots help airflow pass into the wing from the sides. The more flow you can pass through the wing, the more downforce it will produce.
Williams, Force India and Marussia all use a similar solution.
Caterham & Williams Exhausts
Following the FIA's advice at the previous test, both teams have removed the disputed bodywork around their exhausts.
Due to the rain, Williams had to bin a planned aero test this morning and removed the sensors from the car.
Now the device's presence is well known, more images of the Williams blown wheel nut solution are available. First noticed at the car's launch, Williams has opened up its axles to allow a duct to pass inside and blow air through the wheel to reduce the drag created behind the wheel.
Williams's blown wheel nut solution © XPB
Looking up close its clear to see the duct is far from simple. The duct is broadly semi-circular and the outlet points upward. As this duct does not rotate with the wheel, it can blow into the correct location far more accurately.
Last year, Red Bull also blew air though the axle, but the outlets were formed in the axle and thus rotated with the wheel, so they blew in all directions which was less efficient.
No other team has yet suggested it will follow this solution.
Whereas Williams blows air directly out of the axle, Sauber, like most teams, directs airflow around the brake duct drum.
This airflow helps to drive the heated flow from the brakes out of the wheel. The flow also serves to prevent the heat generated by the brakes from passing into the wheel and overheating the tyre.
Sauber directs airflow around the brake duct drum © XPB
With Sauber's brake ducts, you can see that airflow is directed to circulate in the same direction as the wheel's rotation.
The blue stripe around the brake drum is a seal which prevents air passing out from the inside face of the wheel.
Also, note how the axle is pointed. This helps the mechanics fit the wheel during pitstops.