Red Bull RB7 Renault

[PlatinumZealot]

Where marginal is defined as "not enough to cool the KERS battery too – my guess is this is what is meant by newey not compromising his aero design for KERS – it's not that there's not room for the parts, it's that there isn't enough cooling, and he doesn't want to make the sidepods longer.

HOOLD on... I was refering to the water radiators. That takes up the most space in the sidepod. KERS oil cooling radiator is not that big. And I think KERS radiators size is not the reason for REdBull problems.. It's so easy to make the cooling core bigger. It must be some other reason.

The batteries have enough trouble to charge and discharge in the required time .You put your electronics and batteries into an area with the lowest possible temps to avoid early failure.So putting them into the downstream air of radiators /oilcoolers and exhaust pipes will undoubtedly create a very critical environment....you are flirting with disaster .the usual below the fueltank space is heating up considerably slower so your main concern will be the waste energy of the batts .?

Are you sure they are cooling their batts with oil ?Why that ?

I just said because most of the electrical stuff I see use oil. But now that you mentioned it, give me some background on the batteries first. how hot do the batteries get when not cooled, and do they got hottest during charging or discharging?

Batteries are one thing but what about cooling the MGU?

OK, just some thoughts after you give me these facts I have forgetten from the KERS thread; Is redbull dumb enough to undersized a KERS radiator? I Don't think sooooo!

Even I could size a radiator for their KERS units.. you just make it big enough. Simple solution.

I think the problem is somehting else. Like a problem with a chip, or motherboard, or software.. maybe a chip overheating (not on the cooling circuit) or battery chemicals or cells or some crap like that. But If you know about heat exchangers, you know it's easy to use use a bigger one, or just put a bigger hole somewhere, and RedBull has the biggest hole in the back of their car.

[beelsebob]

OK, just some thoughts after you give me these facts I have forgetten from the KERS thread; Is redbull dumb enough to undersized a KERS radiator? I Don't think sooooo!

I absolutely do – but I don't class it as "dumb", so that's maybe why I can see them doing it. Newey has realised that there's as much advantage in having less cooling, and better aero as there is in having more cooling and better KERS.

I think the problem is somehting else. Like a problem with a chip, or motherboard, or software.. maybe a chip overheating (not on the cooling circuit) or battery chemicals or cells or some crap like that. But If you know about heat exchangers, you know it's easy to use use a bigger one, or just put a bigger hole somewhere, and RedBull has the biggest hole in the back of their car.

Right – but by putting a bigger heat sink on your CPU you don't comprimise something else. By putting a bigger heat sink (read radiator unit) on an RB7 you end up with bigger side pods, and you end up with less clean air arriving at the rear wing.

[BreezyRacer]

Christian Horner said, after Monaco, that the KERS on both cars worked without a hitch ..

[beelsebob]

Christian Horner said, after Monaco, that the KERS on both cars worked without a hitch ..

Yes, but monaco was cool, and didn't involve heavy use of KERS.

[marcush.]

think about delta T .Say you got 120°C sidepod temperature and 130°C Temp in the MGU..the battery and MGU will not like it .
electric/electronic components lose reliability with rising temperatures at an alarming rate ...so anything ambient above 120°C is not going to survive reproduceably.Is this area below 120? the rule of thumb here is you are reducing component life by 50% with every 10°C temperature rise...(ignoring there might be some catastrophic failures at certain temperatures)
So you will need to have a very effective fluid cooling system to keep the average temp in these units down resulting in big radiators in need of air supply ,wich is a pressure drop -drag in the aero department.

http://www.mpoweruk.com/lithium_failures.htm

saft -the current supplier of battery technology in Formula 1 to Renault Ferrari and others has battery technology to work under extreme temperature loads :

press release about their current high temperature applications :
Li-ion opens up new horizons for MWD design
Saft has achieved a world first by creating a robust Li-ion cell capable of charging and discharging at extreme temperatures up to +125°C, while being able to safely withstand temperatures up to +135°C. This major leap in operating temperature, from the current maximum of +65°C, opens up new horizons for MWD tool developers and manufacturers as, for the very first time, they will be able to incorporate a high performance rechargeable battery in their design. In some future applications this could eliminate completely the need to withdraw an MWD tool for replacement of a spent battery, with the benefit of improved continuity for the drilling operation.

The new VL 25500-125 C-size and VL32600-125 D-size cells are intended for use in the construction of batteries to be integrated within sophisticated MWD tools that incorporate onboard alternator technology, driven by the mud flow, to power their electronic systems. When the mud is flowing the battery will be charged. When the flow stops, such as when drilling is halted, the battery will be discharged to provide power for the MWD electronics. When the flow restarts the battery will recharge itself. The fast-charging, deep-discharge and high cycling capability of the Li-ion electrochemistry will effectively enable the MWD tool to remain in continuous downhole operation.

according to another press release they supply VL type li ion cells to formula one .The specs state the internal shut down temperature is 125°C.Interestingly the degradation of the cells at high temperature is immense ,especvially when you consider draining the batteries more than 70%

http://www.saftbatteries.com/doc/Docume ... ea37fa.pdf

[Owen.C93]

Christian Horner said, after Monaco, that the KERS on both cars worked without a hitch ..

Yes, but monaco was cool, and didn't involve heavy use of KERS.

Monaco is a high cooling solution track and since the lap is short a higher percentage of the lap is KERS enabled and there's 70odd laps in which you can use the 7s boost.

[beelsebob]

Saft has achieved a world first by creating a robust Li-ion cell capable of charging and discharging at extreme temperatures up to +125°C, while being able to safely withstand temperatures up to +135°C. This major leap in operating temperature, from the current maximum of +65°C, opens up new horizons for MWD tool developers and manufacturers as, for the very first time, they will be able to incorporate a high performance rechargeable battery in their design. In some future applications this could eliminate completely the need to withdraw an MWD tool for replacement of a spent battery, with the benefit of improved continuity for the drilling operation.

The comparatively narrow gap between operating well and blowing up would seem to confirm to me that they can't cool the batteries enough – it would make perfect sense for them to ask drivers to stop using KERS when it hits 125° or above to a) get it back into an efficient operating zone b) stop it operating like a bomb.

The comparatively old LiIon tech is more susceptible to being damaged by this kind of behaviour than newer LiPoly ones anyway. I'm pretty surprised actually that the teams are still using it.

[marcush.]

considering engine compartment temps in current production cars hit 120°C on a fairly regular basis and you have those temperatures downstream of the radiator ,I´d be surprised if we would not see considerably more sustained temperatures in the sidepods downstream of the rads....So no surface cooling in that area for your battery available it all has to go into the cooling circuit and you need to bring the coolant temperature down to a useful level to arrive at an efficient battery temp...
The aim of downsizing battery pack and minimising cooling capacity is really a severe tradeoff and you soon arrive at not only volume but mass as well if you are looking at a 100% availability and minimum degardation during the race.

[Raptor22]

While investigating the purpose of the hole in the rear of the bodywork of the Ferrari (and Red Bull), I came across this article by scarbs, where he notes that the absence of bodywork at the rear of the car is a clear advantage:

If you look at the RB7s sidepods, from the radiators back they appear to slope away to nothing. This leaves the distinctive flat floor and open area ahead of the rear wheels. This creates an obvious aero gain, but how is cooling achieved with such a tight design?

from http://scarbsf1.wordpress.com/2011/02/1 ... d-cooling/

So how is having 'naked floor' at the rear an obvious aero gain?

It allows the air to slow down and create higher pressure on top of the floor.
coupled to lower pressure under the car due to diffuser efficiency and you have more downforce; in the simplest possible terms.

[marcush.]

the whole coke bottle shape sidepods rearend is aimed at minimising flow restrictions between the rear tyres and avois converging flow if i understand correctly .So the aim is to have as little obstruction between the wheels at possible and create a smooth transition forward to the sidepods .Venting hot air coming from the radiators cannot be a good thing as you add slow mass flow adding drag.redirecting the hot air exits behind and above the rear wheels must be an advantage ?

[PlatinumZealot]

You guys are missing my points!

I think these questions have to be answered first.

When does the RedBull KERS give problems? Did it happen on one car? Both cars? at the same time? Is the system disabled or can it be charged? Can it be discharged?

Then

1. Who says Battery cooling is a problem?
2. Where is their KERS radiator(s)? Who says it is in the side pods?
Do other teams have bigger side pod openings? (Check Ferrari & Renault & williams)

3. Is it for the battery alone or MGU alone or MGU + Battery?

4. What is the recommended teperature range for the batteries?
5. What is the recommended temperature range for the MGU?

6. Does the battery temperature rise most on charge or discharge?


Who can answer these questions?

When you do lets work this thing logically.

[beelsebob]

You guys are missing my points!

I think these questions have to be answered first.

When does the RedBull KERS give problems? Did it happen on one car? Both cars? at the same time? Is the system disabled or can it be charged? Can it be discharged?

Typically yes, on both cars, no not at the same time, and only at certain races – to me, this points to environmental factors, and something changing in the car. Heat build up would explain that nicely.

1. Who says Battery cooling is a problem?

No one does, but it's certainly not lack of space, and newey is talking about "fitting it into his design", the only way I can interpret that is "get it inside some limitation other than space", and heat seems to fit this too. The worst affected component would be the battery.

2. Where is their KERS radiator(s)? Who says it is in the side pods?

Also a good point, but I'm not sure it matters – smaller side pods means less cooling ability in them, means less total cooling for the car. If cooling is margional, and newey doesn't like KERS, it's entirely plausable that it was the first to be sacrificed on being margional heat wise. It's also a great choice because it's easily shut off without affecting the rest of the car an enormous amount.

Do other teams have bigger side pod openings? (Check Ferrari & Renault & williams)

It's not about opening size – it's about total radiator surface area in there, and assuming the teams are roughly equally good at designing radiators to have big surface areas, the volume of the side pod will correlate to the amount of cooling they can provide – RBR's is particularly small.

3. Is it for the battery alone or MGU alone or MGU + Battery?

We've seen the batteries packed onto the side of the gearbox, that isn't where you need to put an MGU, so yes, they must be seperate

4. What is the recommended teperature range for the batteries?

We saw above – under 120° to operate well, under 130° to operate at all.

5. What is the recommended temperature range for the MGU?

Pass

6. Does the battery temperature rise most on charge or discharge?

Typical LiIons will heat up while charging more than discharging, but my guess is that that's actually to do with there being a greater current when charging. An MGU will draw current like crazy while operating, so it's plausable that theirs will heat up a lot while discharging too.

[aral]

You guys are missing my points!

I think these questions have to be answered first.

When does the RedBull KERS give problems? Did it happen on one car? Both cars? at the same time? Is the system disabled or can it be charged? Can it be discharged?

Then

1. Who says Battery cooling is a problem?
2. Where is their KERS radiator(s)? Who says it is in the side pods?
Do other teams have bigger side pod openings? (Check Ferrari & Renault & williams)

3. Is it for the battery alone or MGU alone or MGU + Battery?

4. What is the recommended teperature range for the batteries?
5. What is the recommended temperature range for the MGU?

6. Does the battery temperature rise most on charge or discharge?


Who can answer these questions?

When you do lets work this thing logically.

There is a person named Adrian Newey who can answer these questions for you.
But some of your questions have already been answered.

The system can be disabled by the driver. Vettel was told to turn his unit off.

When energy is being passed to battery, of course the temperature will rise

When discharge is in operation, the energy is passed to the motor, so the battery will not have a temperature rise.

Battery cooling is the problem, and this has been continually stated by RBR.

Both cars have suffered from KERS problems, sometimes at similar times, sometimes not. Webbers car probably suffered more as it is rarely in clean cool air, even at the start where it is normally sitting in the heat output of another car.

[PlatinumZealot]

Keep the answers coming. I am not that satisfied with most of them though and some are wrong.

This is a technical site so I want to see some more technical answers and sources so we can discuss without speculation or interpretation.

I will give break it down myself, and give my view of things.

Another Gem for you guys..and an hones question: did you see any heat shielding on the RedBull KERS object that is beside the gearbox?

(Notice I am not saying it is a battery, I do not know what it is, but all other teams have batteries under the gas tank).

[beelsebob]

Keep the answers coming. I am not that satisfied with most of them though and some are wrong.

This is a technical site so I want to see some more technical answers and sources so we can discuss without speculation or interpretation.

I will give break it down myself, and give my view of things.

Another Gem for you guys..and an hones question: did you see any heat shielding on the RedBull KERS object that is beside the gearbox?

(Notice I am not saying it is a battery, I do not know what it is, but all other teams have batteries under the gas tank).

Heh, touché. Though it's an odd shape to be anything but the battery, or I guess a control unit.