Renault R31

[Owen.C93]

I think the reason it worked on aeroplanes was because of the propeller was supplying even faster air through the radiators.

[marcush.]

going too close to the propeller blades will have a bad effect becaus eof the strong pulses I read.Turbulent air is a no go according to the papers.

[Blackout]

Thanks AbbaleRacing77 for your answer.

Hard to see, but in this photo, the radiators do not seem to be very inclined...



And the size of the gurneys here is maybe a proof that the flow comming from the outlets is powerful.

[AbbaleRacing77]

Your assuming that Renault is using a conventional radiator. Yes the radiators may or may not be tipped on an angle. But I'm sure a team like Renault could develop a radiator with the cooling elements angled so the end result is air flowing straight through the radiator. But I'm sure that I'm not thinking about this before renault did. Now do you honestly think a car moving at 200 mph with these big sails they call sidepods hanging off the side of the car being fed by the angle of the front wing is incapable of producing pressure when trying to squeeze the air back out a hole half the size the hole it went into? Oh yea and don't forget the fact that the air is gonna expand once it passes the radiator and red hot headers to produce even more pressure.. This is not a complicated piece of engineering and if this is not what they're accomplishing maybe they should look into it.

[AbbaleRacing77]

Someone asked why the sidepod inlet are so big... Blown side pods is my final answer

[SiLo]

Maybe because they had to bring the exhausts forward from the manifold? So they needed to move the radiators to free up some space to the side/behind them.

That's my two cents anyway.

[Twaddle]

I understand that, I just don't think that passing through radiators and the rest of the car will result in an accelerated flow out of the rear.

I could be wrong.

The way I see it:

That exit is tiny compared to inlets. This very simply leads to either the air coming out at higher speed than it went in, or the system choking and then cooking relatively quickly. I don't remember them blowing up every time they went out, so I guess it works and the air comes out faster.

[forty-two]

I know nobody actually asked for it, but my thinking on this is:

Because they're routing the pipes forward, right past the driver's backside, they need to cool the pipes, so they went for bigger inlets, at least on the initial car. How bad would it look if they cooked one of their drivers on the 1st test? I wouldn't be surprised if we one day see exhaust pipes with cooling vanes on them to act as a heatsink for this reason. Whether this will have the effect of cooling the exhaust gases so much that they become less useful is more a question for the thread in the Aero section.

I don't think that the sidepod inlet size versus outlet size will actually accelerate the air coming out the back per-se, perhaps the pressure will be increased, but if anything surely the speed of the outlet air will be reduced somewhat? Think about it, if you pour water into a funnel with a tiny neck, it doesn't seem to come out any faster if you fill the funnel.

I'm sure that some of the esteemed aero-nuts on this forum will be able to set me straight though!

[marcush.]

as said before ,Ihave not seen any of the current rads in detail.Do F1 teams manufacture their very own cores and would they be able to produce something better than Modine or Visteon?It seems unlikely you could do that with the sort of equipment available in a F1 team. From what I saw last year Renault was using very small cores in very much upright position (compared with say the Toyota /RedBull layout)This will give them a much longer duct and much less cross flow).
As for the duct entry and exit area .A shorter duct will need a bigger opening simply because the air will not bend around severe curvature or steps.If your duct is say 150mm long there is not much you could do to have less than the radiator area as an inlet size .with A exit duct of over 1000mm and say a convergence of 7degrees the exhaust size can be small without restriction.The air will not pass the radiator without loss of speed.It will experience surface drag ,and it will only gain energy in the form of heat and will expand reducing density.This duct is not a closed isolated system .Asuming you grab air at ground speed and you build up pressure with your duct design why should the air enter this high pressure area? Flow is attracted by low pressure if I´m right.You will need to vent your hot air exits into areas of low(er) pressure to get things working.To put a funnel in front of the entry will not help much.

[AbbaleRacing77]

Yes i think theyre capable of producing or at least coming up with whatever specification they need after seeing the radiators on the the Mclaren. I also think that the volume of air going in will make up for the friction of the radiators.

[Dragonfly]

I don't think that the sidepod inlet size versus outlet size will actually accelerate the air coming out the back per-se, perhaps the pressure will be increased, but if anything surely the speed of the outlet air will be reduced somewhat? Think about it, if you pour water into a funnel with a tiny neck, it doesn't seem to come out any faster if you fill the funnel.

I'm sure that some of the esteemed aero-nuts on this forum will be able to set me straight though!

I think it's quite a wrong comparison. You try to compare gas with a liquid. And while water (liquid) would behave almost like a solid body under compression, gas on the opposite has a huge coefficient of compression and expansion.
Sorry, if I am wrong, I'm not a specialist, but I know this from the principle my Xantia's suspension works on.
In addition, you don't change the energy level of the water, pouring it through a funnel. Cool air taking heat from the radiators and other blown hot components means it gets energy.

[AbbaleRacing77]

Try adding pressure to that funnel with say... 200mph wind? See what happens... Its like putting a nozzle on the end of a hair dryer. Would the air come out with greater velocity than it normally would? I would like to think so.

[marcush.]

the inlet of the duct is a lot smaller than the radiator size .The air speed through the core is a LOT slower than ground speed.the relationship looks like inlet size is maybe one 5th to one 4th of the inlet size usually .the renault is BIG thats true ..more like half of radiator size..

[djos]

as said before ,Ihave not seen any of the current rads in detail.Do F1 teams manufacture their very own cores and would they be able to produce something better than Modine or Visteon?It seems unlikely you could do that with the sort of equipment available in a F1 team. From what I saw last year Renault was using very small cores in very much upright position (compared with say the Toyota /RedBull layout)This will give them a much longer duct and much less cross flow).

Actually most top teams including RedBull are using PWR radiators made in Australia.

[AbbaleRacing77]

Marcush the design of the bodywork seems to show otherwise and honestly i think your only guessing as to what the friction of the radiator is with no facts at all. This is Renault F1 not Daewoo, they can design a radiator with less drag if they want to and make them a little bigger to make up for the lost cooling (which definately looks plausible because the radiators look huge). For all i know they couldve had big bob in the boonies making these radiators by hand for the last year... nobody knows

And even if the radiators have high friction it shouldnt matter because were talking about air being rammed through a sidepod here... Im not talking about a freestream of uninterupted air. Air isnt gonna just bounce off the radiators, the air is gonna be forced through via constant pressure, and that air is gonna go somewhere. That "Somewhere" is a much smaller hole out the back which will result in a higher velocity well shaped flow of air over the diffuser. Your claim is like saying that you cant have a air ram intake because the airfilter creates some friction which we know in the 21st cetury is untrue. Why? because air ram has constant air pressure. Except the volume of air intake to the hole where it exits on the sidepods is an even greater ratio then a ram air intake. Which infact makes my theory very plausible and most likely true.

Renault couldve made the exits out the bodywork like redbulls big hole out the back in order to create a better "undercut" sidepod but they didnt... They shaped the exits flat and smooth to direct air over the diffuser and they did it for a very good reason.

Please dont make me whip out the crayons my drawing skills are terrible