Car: Red Bull Racing – Renault RB8
There’s not a lot left to be said about Red Bulls incredible run of pace since 2009. Despite not winning the 2009 championship, the RB5 rewrote the text book on F1 design. Since then, the two subsequent cars have both pioneered new ideas and followed a few others. Each time the car has been ever more dominant. If the team have an achilles heel, then its reliability, split between the; chassis, the engine and KERS. With pace in hand, the team do not need to make bold steps with the cars design, as they need to maintain reliability. With the RB8 taking risks was not on the agenda, the evolutionary car uses detail design and a small few unique features to keep a step ahead on pace.
With the evolutionary concept, no obvious changes have been made with the cars layout. The retains a steeply raked attitude, Newey mentioned at the launch that the loss of EBDs will affect their ability to angle the car into the nose down attitude. But the evidence of the car on-track suggests that obtaining laptime with a lot of rake is not an issue.
As with many teams, the nose grabbed most attention when the car was launched. But rather than the shock from the awkward looking 2012 noses, there was curiosity over the letter box slots in the nose. There was one more visible slot on the upper section of nose and one less visible one below it.
Rumours circulate that the upper slot is used for some form of F-duct or (non driver) cooling. In my opinion, it is a simple solution to keep the airflow attached over the step in the nose.
Faced with the 2012 rules, Red Bull took the obvious route of a raised chassis and nose. The car now eschews the “V” shape nose and chassis, so the top of the chassis and nose are flat. With the rules forcing a 75mm step between these two surfaces, the airflow doesn’t want to run along the nose and then step up without separating from the chassis top.
So the team has sought to offset some of problems with this design. Red Bulls solution is to create an aero effect to aid the transition between nose and chassis. This starts with the letterbox inlet, which as Newey explained at the launch is ‘primarily’ for driver cooling. The rules permit one opening to the nosecone for the purposes of driver cooling. Normally this is an oval hole in the tip of the nose. But on the RB8 this is a 25cm wide narrow slot and probably only 5mm or so high. As Newey admits, some of this airflow does pass into the cockpit to cool the driver. But what Newey would probably describe as the secondary effect of the slot, is to allow for the rounded leading edge above the inlet. When airflows runs up the nose it hits this leading edge and curls under it, forming a bubble of recirculating flow. This rotating cylinder of airflow helps to keep the upper airflow aligned and attached to the flat top of the chassis. This is a simple and copyable solution. I believe this would work with or without the slot. As the upper section of nose cone bodywork is largely a cosmetic panel and not part of the crash structure. It could be changed without re-crash testing. Sauber have found a similar solution on their nose.
Below the nose there is yet another slot. This in line with the bottom of the chassis and runs the full width of the nose. While I can offer some explanation for the upper slot, this lower one is more of a mystery. Again its use has been rumoured as KERS cooling or blowing the floor, whatever its function I believe it may have been on the car last year. Although the slot was not externally visible on the 2011 car, when the nose is removed the slot was evident below the front bulkhead (pictured below). Presumably this was fed from the driver cooling inlet, which was placed on the nose tip on the RB7.
Clearly the duct formed is very small, which limits it use. I doubt it’s to cool KERS, as the KERS is mounted towards the rear of the car and the small duct would not adequately cool batteries or the like. Its position does suggest the flow could pass down to the splitter, so some clever use for blowing or loading the splitter could be within the realms of possibility. More likely is the use to cool the electronics or power steering rack, which are sited much closer to the duct and would require a smaller amount of cooling air.
One detail of the RB8 and to an extent with the RB7 was the advantage it takes of the radius that is allowed to be applied to the edges of the chassis. This 25mm radius is rounded over to keep the cross section of the nose as small as possible. Within the minimum 300mm x 275mm rectangle the nose must fit into. The top corners of the chassis are clearly a near 3/4 cylindrical section.
In common with their rivals the front wing is a derivative of the 2011 wing. Albeit restructured to meet the newly doubled deflection test. Red Bull were late to the endplate-less wing design. Although they created slot in the endplate over the past few years, it’s relatively recently they upper section of endplate has been added on to the tips of the wings, rather than use a conventional separate endplate.
Behind the wing the turning vanes continue the mid 2011 ‘curled’ design. The vanes hang from below the chassis and are larger this year and sport a split in the middle.
One odd feature visible on the front wing is a small section of removable bodywork in the neutral centre section of wing. I’ve idea of the purpose of the purpose of this panel, perhaps its to access a sensor or allow ballast to be fitted?
While retaining the same engine and with the general evolutionary theme of the car, the roll hoop area is indistinguishable from the 2011 car. No doubt there are structural changes under the skin, but these aren’t visually apparent or announced by the team.
Moving onto the sidepods, the general concept of the sidepod shape is also similar to 2011. Slightly triangular inlets feed the radiators, which are mounted horizontal across the car and tilted upwards towards the front. Their flow passes up and around the heat shielding on the engine\airbox and most of it exits through the tail funnel. In cross section the sidepods retain the outwardly-tapered ‘jelly mould’ appearance, with only the area under the inlet being undercut. Again as with the RB7 the sidepods merge seamlessly into the gearbox fairing.
Traditionally Red Bull have switched their launch exhausts to their Melbourne spec in the last days of testing. It’s been mentioned by the team that there is a new exhaust system coming. This is no doubt partly the reason for the team delaying the last test and having a near private test (shared with Ferrari) on the last day.
The launch spec exhaust places the outlet pipe inboard and relatively low. This bows in line with the plane of the rear upper wishbone. The bodywork over the gearbox and rear crash structure is curved and creates a neat channel for the flow to pass through. This then sees the exhaust plume pass under the beam wing. In this position the heat is affecting the upper wishbone, even at its launch, the car sported heat shielding over the wishbones. During testing this protection has grown, albeit with temporary looking solutions, suggesting the new exhaust system will not blow in this area.
The RB8 has a high mounted upper rear wishbone, which places its rear leg in line with the beam wing. In keeping with the recent RBx cars, the gearbox sports a tall spine that functions as the wishbone and beam wing mounting. Although this shaping is partly hidden by the way it merges into the tail funnel.
With such a high top wishbone the lower rear wishbone is able to mount higher too. This wishbone is now effectively at the same height as the driveshaft. Not only is it inline, but the wishbone forms an shroud ahead of the driveshaft to offset the negative aerodynamic effect of the rotating shaft, in the critical area above the diffuser (Note: Fully shrouded driveshafts are banned). While this all appears to be logical, the lower wishbone is not a splayed as the upper wishbone. Having the inboard mountings very close to each other is not so good from a loading perspective, so there must be a reason to make the wishbone in such a compromised shape. Again this might suggest the new exhaust needs the wishbone in a certain position to work effectively.
Diffuser\rear impact structure
With the tapered sidepod, the Red Bull encloses the centre of the diffuser inside the gearbox fairing. Other teams leave this exposed beneath the crash structure, to allow flow to pass through and out of the starter motor hole. Last year Red Bull introduced a duct in the floor to send flow directly to the starter motor hole. This year the duct appears to have gone and doesn’t look like it’s been replaced with something. In line with the gearbox and the current exhaust set up, the impact structures forms a spine along part of its length. Once the beam wing is mounted to the spine, the crash structures returns to a normal rectangular cross section and sweeps upwards towards the tail light. This spine format keeps the gearbox and suspension mountings nice and stiff, plus it mounts the beam wing with very little obstruction to it slower surface.
Red bull have used pull rod suspension since 2009 and introduced their carbon fibre gear case in the middle of that year. Keeping the construction and general shape, the gearbox set up appears only have detail revisions over this period.
Every team has exploited the 12cm of space inboard of the rear wheel for aerodynamic bodywork. Red Bull have added particularly large upper vane to the brake ducts this year. Above the top wishbone mounting two large flap can be seen.
The rear wing also exploits a small window that allows bodywork, this makes it possible for Red Bull to fit vanes placed behind the diffuser, to aid the expansion of the flow out of the diffuser.
It was a bold decision in 2011 for Red Bull to develop their own Battery system for the Renault Marelli KERS. Not wanting to sacrifice wheelbase and fuel tank volume with under-tank mounted batteries, instead Newey mounted the batteries near the gearbox. In fact three batteries packs were fitted, one larger pack either side of the gearbox and a small array inside the top of the gearbox case. Exposed to more heat and vibration the KERS caused problems throughout 2011 and led to the driver having it unavailable at critical points in qualifying and races. I understand the battery positions remain for this year. It was never clear if Red Bull actually had a full power KERS in 2011. The rumours persisted of a Mini-KERS, suggesting the system discharged nearer 40Kw, rather than the maximum allowable 60Kw.
Announced in mid 2011, Red Bull are now the official ‘factory’ team for Renault. With the success of the team and the Renault F1 team being rebadged to Lotus, This allows Red bull to take a more direct involvement in developing the RS27 engine and the exhaust mappings to maximise what is allowable in the rules.