Red Bull RB7 Renault

[marcush.]

come on -what do you think are the challenges technically in a f1 car besides compact packaging?
Temperatures first and vibrations second are your worst enemies in anything electric electronic.
The Marelli statement is 120°C working temperature for all components.-But every increment of lower temp will DRASTICALLY improve reliability.

As the system is switched on and off it seems fairly logic that not ambient but temperature rise when using the unit is a problem-hinting at cooling of some cpomponents is marginal.So it looks like a fail safe kicking in ,or better a sensor readout is advising to shut down the system.

so we can clearly analyse from our cosy couch that RedBulls system is marginal on in use temperature .
BUT it does not slow down the car dramatically as well.At least the system is under control enough to prevent dnfs so far in the race.

sure we cannot suggest an improvement as we lack al the detail of information.But obviously the team is not in a position to erase the root cause...simply because there are no better parts available commercially.
Usually design weaknesses lead to implementation of expensive special stuff (coatings ,exotic materials)but what to do when your environment is simply too hot for your component to be able to work ? you can only add cooling performance -adding weight and drag costing outright speed .So Neweay is reluctant to swap aero performance for KERS performance with the risk of a kers failure and still have sacrificed the aeroadvantage (or part of it).I´d call this risk management.

with reference to the picture :
what do you think is it??? the Controller? The MGU? there is not many things that come in boxes and we have not even seen the part on the other side ...The car is not complete so we don´t know how it looks raceready.And we don´t even know if the pic was taken from a unit operative...as we have learned that more than once they have opted not to have it ..but of course they need to run the ballast exactly there...

not very technical but:
http://www.f1sa.com/index.php?option=co ... Itemid=157
and from Scarbs blog the picture of the KCU under the rhs radiator:

looking at the evidence it seems fairly straightforward that Battery temps are the main concern here the KCU seems to be installed in a very conventional position nothing hot nearby so the 120 limit is really the waste heat of the unit itself which is restricting ...for the batterry which is in my view even more vulnerable the temperature situation (ambient) is more severe. hinting at the problem area.

[PlatinumZealot]

I wouldn't draw a conclusion so hastily.

Remember You guys sited a radiator and packaging issue with KERS. I say you can make the radiator bigger and increase flow to the radiator by making bigger openings. This is an easy problem to solve. This has to do with the physical shape of the duxting and radiator size, and you guys were looking at the teardrop shape of the RBR and assuming it was the reason why the KERS overheats - so I instantly disagreed with that being the issue.

The problem must be a more difficult one that is not related to the packaging of the car.

So it is established:
The Batteries need cooling.
The MGU is a motor that needs cooling.

Marcush, says the system operates at 120*C. Source here: http://www.f1technical.net/news/11101

Towards Racecar Engineering, Magnetti Marelli showed off its system specifically designed for F1: "The system itself is fairly conventional, using a single liquid cooled brushless direct current motor generator unit (MGU), which operates at around 120°C. Also included in the system is an in house designed KERS Control Unit (KCU) with a similar temperature capability. The battery pack is an outsourced part due to the complex chemistry involved in its development."

Now, IFit is a heating problem, It can be these thigs you overlooked:

1. you guys forget that there has to be a heat exchanger on the MGU side and battery side of their respective cooling loops. If you look on most industrial motors you see fins and fans over it. For internal combution engines you have to have the water jackets big enough for proper heat exchange. Many times we hear stories of cracked engine blocks and molten turbine blades due to bad coolant passage design. If these internal Heat exchange surfaces were designed wrong by RedBull they could run into problem. And yes, this is not related to the packaging.

2. How is it that Marc Webber's KERS overheated more than Vettels? They have the same design! What causes that? I drive the same model Toyota Corrola as you, but I have overheating problems and you have none. There is obviously some fault in the system itself, like a bad thermostat, bad temperature sensor. I do not want to include marginal temperatures, because from an engineering standpoint, the system has a margin of safety. Going a few degrees over won't cripple the system. Like driving your car with the water temp guage on Red. So is a possibility of a faulty component - which does not relate directly with the how Newey Packages the car.


Then now. It was not said if it is a cooling problem. Because lets face it, the temperature of the system isn't just going to rise up randomly int he race, and it was running cool all weekend.

There could be other problems too..

[imightbewrong]

"Saft supplying five Formula 1 KERS cars with VL li-ion batteries"
http://green.autoblog.com/2011/04/21/sa ... ies-video/

So, lets take their batteries as a reference. Check out one of their high temperature cells:
http://www.saftbatteries.com/doc/Docume ... 18f753.pdf

Just compare the curves for 115C and 125C. I know these are extremes, but the difference is quite big. And we haven't seen what happens if they exceed this 125C limit, but I'd suggest that site as a starting point to find out more.

[beelsebob]

I wouldn't draw a conclusion so hastily.

Remember You guys sited a radiator and packaging issue with KERS. I say you can make the radiator bigger and increase flow to the radiator by making bigger openings. This is an easy problem to solve. This has to do with the physical shape of the duxting and radiator size, and you guys were looking at the teardrop shape of the RBR and assuming it was the reason why the KERS overheats - so I instantly disagreed with that being the issue.

You're slightly misinterpretting what was said.
1) No assumption was made – I suggested that it might be the case
2) No one said that cooling couldn't be improved by increasing radiator surface area or intake size, they said that this correlates with what newey said – doing either of those would cause the aero to change, and newey is clearly of the mind that the aero is worth more than the KERS being reliable.

The problem must be a more difficult one that is not related to the packaging of the car.

Except that it's been repeatedly stated by the team that the issue is that Newey didn't want to give up his packaging just to get KERS.

1. you guys forget that there has to be a heat exchanger on the MGU side and battery side of their respective cooling loops. If you look on most industrial motors you see fins and fans over it. For internal combution engines you have to have the water jackets big enough for proper heat exchange. Many times we hear stories of cracked engine blocks and molten turbine blades due to bad coolant passage design. If these internal Heat exchange surfaces were designed wrong by RedBull they could run into problem. And yes, this is not related to the packaging.

I'm really not sure what you're getting at here? Are you asserting that the thing we can see with a lightning bolt on it doesn't have lots of fins and fans on it and thus can't be the battery or MGU? Does the position of the battery or MGU really matter to the argument that the battery could be overheating.

2. How is it that Marc Webber's KERS overheated more than Vettels? They have the same design! What causes that? I drive the same model Toyota Corrola as you, but I have overheating problems and you have none. There is obviously some fault in the system itself, like a bad thermostat, bad temperature sensor. I do not want to include marginal temperatures, because from an engineering standpoint, the system has a margin of safety. Going a few degrees over won't cripple the system. Like driving your car with the water temp guage on Red. So is a possibility of a faulty component - which does not relate directly with the how Newey Packages the car.

1) Batteries are fickle things, different battery packs behave very differently. This could explain a lot of why their "solution" at a lot of races has simply been to dump new batteries in it.
2) Webber generally runs in dirtier air than Vettel, meaning he's getting less cooling.

Then now. It was not said if it is a cooling problem. Because lets face it, the temperature of the system isn't just going to rise up randomly int he race, and it was running cool all weekend.

No, but again, the argument is that they are margional on cooling – meaning that while KERS is in use it's getting hotter, and while it's not it's getting cooler... The result, exactly what you see in the race... It gets hotter and hotter, the team tell the driver to turn it off... it cools down... they get to turn it back on again... rince, repeat.

[marcush.]

we cannot make a full analysis here .
But with a "special" solution in all areas for RedBull it seems reasonable that we do not see anything like a process well under control ...hand crafted things tend to have a bit of extra tolerance as human factors come into play.
the buzz about industrial production really is repeatability ...
So the difference between cells / cellpacks and Batterry units may or maynot be an issue here.Also we have to consider the possibility that heat input from the car is very variable..maybe webbers car could not leave the pits for some reason and this overheated the battery environment beyond a critical temperature and in consequence degraded or even killed a battery ...or Vettel took a more severe bump over a curb predamaging a cell ....who knows.So the same applies to every component in F1 cars: the environment is very harsh and there are a lot of contributing factors ,especially heat(rate of change!) and vibration of course very difficult to pinpoint what exactly would cause one driver /car combo suffer more than the other and prove it was not simply a statistical coincidence that mainly one driver is affected.We had those issues with engines (Sato for example) and Vettel last year..
To call the issues they have not design is really naive in my understanding .Newey is responsible for the car ,and when he states he would prefernot to have it ...you know it all.It´s a unloved appendage to his child..and it has low priority .So he willn ot change his aero for it .And so improved cooling is a no go in terms of more area or airflow in the heat exchangers ..I think he wants to push his guys to reduce waste heat production or maybe improve heat transfer -could be done by speeding up the fluid pump for example if the fluidpassages are even allowing to gain something there.

[kalinka]

+1 for marcush

[Raptor22]

I'm not sure at what temp the KERS operates but 120 Degrees Celcius does sound reasonable.
All the components require cooling from the electric motor to the batteries to the regulator. there would have to be battery eliminating circuits contained within and there require cooling as well since steping up and down of voltages is down at an efficiency and the loss is heat.
Good airflow to these devices is critical to their correct functioning.

[marcush.]

the high temperature environment of 120°C is manageable as this is what todays automotive industry demands for engine bay electric/electronic components.
Even 135°C is going to be no issue if the component has not the requirement to be operative at these temps.
The question really is,has redBull failsave strategies implemented to avoid failures? I think not ...as we have heard pitcommunication -not to use kers ,or to shut it down or to restart it.
Let´s assume the driver is a bit late in shutting down an overheating component,or he is still using it ....not much in terms of control in this system methinks.
remember Mercedes in the first race this year ...they had the system shut down and restart on its own due to their temp issues a full systems protection in place as it looks at thee expense of the driver being surprised by sudden status changes in unconvenient moments. Very clearly Mercedes has either optimised their temperatures or has implemented different strategies to avoid discomfort to the driver in KERS to be shut down moments.

[hardingfv32]

How would brake balance be handled during a lap when the KERS is recharging? Would the driver need to adjust brake bias once the charging is completed?

Would you expect the systems to charge as fast as possible if temp control is not an issue?

Brian

[kalinka]

We saw that battery capacity is not a problem if KERS is working fine. If a driver uses up all of the avaliable KERS in last corner, usually it jumps to 100% at start-finish line, obviously without needing to brake. So they have more battery capacity than only for 7sec. So I guess they could balance the brake bias during a lap, becaue they need to charge batteries even when the KERS is not 100% avaliable, and they can play with a KERS charge-rate too. In fact the displayed KERS % is not related to real battery charge %, but it's a known fact.
But I can imagine a situation when KERS is recharged much earlier during the lap, but you can't discharge it ( rain ), but I think it's a problem only for couple of corners, because if IIRC the drivers can adjust KERS charge rate on steering wheel, but certainly they can switch it off.

[aral]

The battery is charged well before the start finish line, but its use is only activated at the s/f line. But there are occasions when the use of the laps supply of KERS , could be used by the driver on the drive out of the last corner.
In that case, it would only begin charging the next time the brakes were used.

[beelsebob]

The battery is charged well before the start finish line, but its use is only activated at the s/f line. But there are occasions when the use of the laps supply of KERS , could be used by the driver on the drive out of the last corner.
In that case, it would only begin charging the next time the brakes were used.

Hamilton showed that at least on the McLaren they're perfectly capable of using a very large chunk of the KERS out of the last corner, and then using a large chunk immediately over the line when he passed Button in China. I can't remember where I saw this, but somewhere I remember reading that most teams had about 170% of a lap's worth of battery capacity to offset the fact that you may use it all in a rush at the end of one lap and beginning of the next.

[kalinka]

Yeah, that was my point too. At least in McL KERS is much more capable than only one lap. Your guess seems OK to me. I'd say it's at least 140%, but your number is probably the better guess.

[PlatinumZealot]

the high temperature environment of 120°C is manageable as this is what todays automotive industry demands for engine bay electric/electronic components.
Even 135°C is going to be no issue if the component has not the requirement to be operative at these temps.
The question really is,has redBull failsave strategies implemented to avoid failures? I think not ...as we have heard pitcommunication -not to use kers ,or to shut it down or to restart it.
Let´s assume the driver is a bit late in shutting down an overheating component,or he is still using it ....not much in terms of control in this system methinks.
remember Mercedes in the first race this year ...they had the system shut down and restart on its own due to their temp issues a full systems protection in place as it looks at thee expense of the driver being surprised by sudden status changes in unconvenient moments. Very clearly Mercedes has either optimised their temperatures or has implemented different strategies to avoid discomfort to the driver in KERS to be shut down moments.

So what do you think they changed to solve the issues so far in Hot hot Monaco?

[PlatinumZealot]

We saw that battery capacity is not a problem if KERS is working fine. If a driver uses up all of the avaliable KERS in last corner, usually it jumps to 100% at start-finish line, obviously without needing to brake. So they have more battery capacity than only for 7sec. So I guess they could balance the brake bias during a lap, becaue they need to charge batteries even when the KERS is not 100% avaliable, and they can play with a KERS charge-rate too. In fact the displayed KERS % is not related to real battery charge %, but it's a known fact.
But I can imagine a situation when KERS is recharged much earlier during the lap, but you can't discharge it ( rain ), but I think it's a problem only for couple of corners, because if IIRC the drivers can adjust KERS charge rate on steering wheel, but certainly they can switch it off.

VEry good point. It ties back into why could Vettel only use 20% of his KERS at those moments where Hamilton was chasing him in Spain. We know the battery was charged more than enough to give him the full 6 seconds of 80hp boost. For some reason he could not discharge no more than 20% even when he was pressing the button for it. Then after a few minutes he could.