Since 2003, Renault's sidepod has a huge chimney, which raise the question why they put the chimney on instead of leaving a whole....
Well to my point of view, Renault probably is using the chimney to direct the incoming air flow away from the rear tyre. They must to have realize the advantage of having a chimney that let heat out of the engine and direct the air flow away from the tyre is better than leaving a hole on the sidepod instead.
Another possible reason for a high chimney on the sidepods is that there is less boundary layer effect from the body. The increased airflow past the top of the chimney 'pulls' the exhaust out via relative negative pressure. I have not been paying attention long enough, but I heard that Jordan introduced this concept a few years back?
In favor of the sidepod hole approach, is that the number of slats in that the plate used is easily configured to have 2-4 slats depending on cooling needs. So if the cooling needs are low, less slats and less aero drag penalty. I guess in the same approach, the chimney portion could be made larger/smaller as needed?
I really thought that was McLaren... I am sure that in 2000 they were in place on Hakkinen's car when he was leading the whole race in Barcelona, and then was left behind with a broken throttle (sounds quite familiar )
actually it was Shadow in the late70´s/80´s who first introduced this arrangement ,I think it was the DN8,but I´m not sure .was Tony Southgatethe designer back then?
yes of course it is a good point to move the outlet away from the body surface,and making use of full airspeed siphoning effects instead of boundry layer speed wich is considerably slower as you get closer ro the body surface.
I think the reason for the side chimenys is to improve the downforce on the winglets just behind them. I remember a long time ago reading that Mike Gascoyne said there was an improvement with the chimenys in place.
Like on a wing, the air on the low pressure side travels faster than the high pressure side. So if the chimenys are shaped like an aerofoil slightly tilted outwards, the airflow on the inside will be faster. This flow hit the winglet and the increased air velocity increases the the downforce created by the winglet. So the increase in drag caused by the chimenys traded for more downforce by the winglet.
We already discussed it at the start of the season and as I’ve already said to look at the chimney on the R24 as it was a vertical wing of limited aspect ratio is probably a good explanation, the tip vortex helps to improve the suction, the twist and the varying chord could be a way to improve the vortex strength moving the aero load towards the tip.
Furthermore we should consider the particular shape of radiators on the R24, a sort of “>”, so the flow to the chimney is mainly from the upper part. Someone knows if the upper part is oil or water ?
The other thing about the twist in the chimney is that it works with the airflow, angled into the coke shape that leads to the rear wing, in the lower area where it rises out of the sidepod, but is longitudinal with the airflow in the clean air upper section. They also increase in cross section with elevation--i.e. thickening as it goes up, or tapered upwards. Is this increasing inner chamber area to allow for expansion of the heated air as it rises?
Its interesting to contrast their solution with that of the bar 006 that has kind of hollowed-out, deconstructed form that presents a smaller frontal surface area, but I find it odd how much the side panels (that are even larger in max cooling configuration) that extend out of the sidepods and form the winglet endcaps appear to constrict the airflow towards the coke/rear wing area.
I’ve just bought the current issue of Autosprint (Italian weekly) and there are two pics showing the F2004 in Fiorano with chimneys instead of shark gills, a design very similar to the Renault (I don’t think it’s necessary to remember that Iley, former Renault aerodynamicist is now working for Ferrari). The chimney, not as twisted as in the R24 and with an almost constant chord length, is more inclined, pointing laterally, at the tip it’s almost horizontal and the hole is vertical, so it’s parallel to the winglet endplate (apparently a bit larger than previously, though I’m not sure) and right in front of it. Basically the Renault design with the chimney blowing laterally instead of upward.
On another weekly, SportAutoMoto there’s the suggestion that, alongside with the chimneys, they were probably testing also the Sauber-like radiators that AFAIK are similar to the Renault solution.
PS I know that my explanation probably isn’t good enough but I don’t think pics are available on the web so that’s the best I can do at the moment.
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