The Barcelona test at the end of February concluded the teams' preparations for the 2010 Formula 1 world championship, and while it has been a frantic, hectic build-up, we are still some way from seeing a crystal clear picture on the form card.
What we have seen however is quite a bit of development, and in Barcelona some of the teams began to evolve their aero packages aggressively ahead of the Bahrain Grand Prix.
One team, McLaren, seems to be the outfit that has done the most development in this area and introduced a significant upgrade on the final two days of pre-season testing.
McLaren's sidepods and turning vane
McLaren's turning vane
On top of the side pods, you can see a slot above the radiator inlets. This has been introduced to match the airflow coming off the front wing. Normally, if you have a nice leading edge along the side pod, you get lift from the top of the structure. By creating this slot it allows airflow through this section to help reduce that lift. Whenever the team needs to generate more cooling, it will probably then just close this off.
By using this slot on the side pod, you're dragging away air that would otherwise go through the side pods, so if you don't need all that cooling, then you might as well reduce the lift. The regulations state that there is a certain distance forward that you're not allowed to have any holes, and the team has obviously gone for one just in front of that.
The bigger turning vane fin is a logical change. There are some very three-dimensional versions of those on other cars - some teams also use them for the wing mirror mounts. It's an area where you want to try and assist the air flow coming out from underneath the chassis and into the undercut area of the sidepod - in the case of McLaren where the Vodafone branding is. There's also a lot of turbulence caused by the hole in the airflow created behind the front tyre, and this device tidies it up.
If there wasn't something to tidy that turbulence up, it would get into the undercut of the side pod, and make the airflow very weak. That would in turn affect how the bargeboard and the downforce-producing devices work resulting in less overall downforce. The key is to always try and make the airflow as neat and tidy as possible.
Like I said, there are much more exotic versions of this than McLaren's solution. But because they are separated from the car, it's an area where development will be continuous - you can always take it off and put another one on. It's not the most expensive thing in the world and you can gain a lot from it.
McLaren tyre temperature sensor and exhaust
The little bump on the floor section has three little eyes in it - these are small infra-red sensors that measure the tyre temperature when the car is on-track, so the team is able to tell whether the tyre is overheating and what the wheel camber is like. It's completely legal to use them and lots of teams do it, but it's a very neat little device..
McLaren has changed the side pods of its developing MP4-25, adding a channel for the exhaust pipe. I think teams are trying to optimise engine performance at lesser revs and this could be a way of doing that, because you're going to need a longer tailpipe if you want to move your power curve to lower revs.
It should be possible to set up the engine so that it performs well at 18,000rpm for qualifying, then for the race make an electronic change in the ignition and fuelling timing and quantity to move the peak power down a little bit to something like 17,000rpm. Although you might lose a little bit of power, the fuel saving will be quite big. If you're losing 10 horsepower - which might be a tenth of a second per lap - you want to make sure that you're saving 20kg of fuel load over the race distance, which is going to be an average of about two-tenths of a second per lap.
Ferrari's turning vane and front suspension
Ferrari turning vane and wishbone
The turning vane under the chassis is a reasonably simple piece of airflow management. Imagine the whole impetus of the airflow under the chassis. The team wants to get that airflow to turn around the bargeboard area and into the turning vane at the outboard corner of the side pod. It then goes through the undercut of the side pod. The earlier you can get some turning momentum into it, the better.
There is one of those vertical vanes on each side of the car, and it is just getting the airflow to turn before it hits the keel area. It does exactly what it looks like it does. As with many of these new parts they are there to introduce the airflow to the downforce components in a better condition to allow them to perform better. It doesn't create any downforce in itself though.
Looking at that lower wishbone leg, you can clearly see the difference in the attitude from the inboard side to the outboard side. This is also designed to influence the airflow.
The inboard part of the wishbone meets the airflow coming off the FIA defined central wing section, which is neutral. It then influences the airflow that hits the section and turns it down from the chassis a little. But the airflow on the outboard side is coming from the front wing flap, so the attitude of that airflow goes up a lot. If you had that inboard section of the wishbone on the outboard, or if the wishbone was at the same angle all the way along, you'd have a lot of separation because the airflow just couldn't stay attached and follow it - it's too abrupt a change.
And that causes more problems, because then you get turbulence which reduces the quality of the airflow to the downforce-producing devices.
Mercedes front wing
I have been quite critical of the Mercedes front wing. If you look at McLaren's it's not really following the Red Bull's solution, but it is a more intricate front wing than the car was released with. There is a lot more complexity to it, and whenever you have more slot gaps and more components in the wing assembly it will help reduce the percentage of downforce loss when you get the inevitable airflow separation on the wing, you can also control it better and get more consistent re attachment.
This new front wing on the Mercedes will give the car more outright downforce before separation happens than either the Red Bull or new McLaren one, but it won't be as consistent. If you're just looking for downforce then this would be a more powerful front wing, but unfortunately during braking and at high speed, the wing is low to the ground and you will get separation from it.
Out on the track you can use this as a tuning device, because it makes the car less pitch-sensitive if you have some front wing separation, but you don't want it to be big percentages. And when this wing stalls it will be a big percentage of downforce lost, whereas when the Red Bull and McLaren wing stalls it will be a small percentage.
The influence that the front wing has on the airflow affects the rest of the car, so it's an area where constant development will go on. But front wing development philosophy is something you have to be very careful about setting correctly. It's not just about making the front wing work in isolation, it's about making it work with the whole car.
Sauber turning vane and keel
Sauber turning vane and keel
The keel area on the Sauber C29 is quite interesting. It uses quite a thick section, and there is a lot of room for ballast there. This area used to be just a thin panel, but it has become a huge development area lately. It's turned into a big container for ballast, because it is the furthest forward and lowest point on the car.
The cars this year have longer chassis, but of course there is no KERS. Last year, I'd have thought that teams would be carrying about 50 to 60 kilos of ballast if they weren't running KERS. The fact that the weight has gone up this year, coupled with the teams agreeing not to use KERS, means that there's even more of this heavy metal being placed around the car, and this thick under section is a pretty good home for it.
The little fin in front of the keel is quite a tricky piece. It's a sort of turning vane, but more horizontal, and again it's another component that is there to influence the airflow off the front wing. It might be that the airflow under that part of the chassis is just a little bit too high, so you just want something to nudge it down that little bit to help introduce it to the leading edge of the side pods at a better angle of attack.