KERS for Dummies?

[diffuser]

Ok, I know in principle what KERS is: Energy that is created while braking. But... then what?
Could someone explain this whole thing without using any more technical terms than you'd need in the explanation of how to butter toast? Please?

[deggis]

"The KERS system is basically a CVT (Continuously variable transmission) connected to a flywheel that engages on deceleration, recuperating some of the energy that would otherwise be converted to heat in the brakes. This spins the flywheel up, which continues spinning until called upon to boost acceleration."

http://www.motorauthority.com/news/m...ecovery-system

As far as I've understood, "KERS" is an acronym (from kinetic energy recovery system) made by FIA, so imho it only means the system F1 will use. It will be introduced next year. Xtrac will make the variators but F1 teams will be making the flywheels themselves.

ACO is also looking for regs (says so in the '08 regs PDF), I hope they keep some sense with it. Unlike FIA because looks like it's going to be very restricted and only allowed to work like a push-to-pass system.

More:
http://www.flybridsystems.com/Technology.html
http://en.wikipedia.org/wiki/Flywheel_energy_storage
http://www.xtrac.com/pdfs/Torotrak_Xtrac_CVT.pdf (PDF)

Also these are interesting:
http://www.autosport.com/news/report.php/id/65226
http://www.autosport.com/news/report.php/id/66521

Was not hard to find these links, just couple of hours ago I was looking for info about this

[gwyllion]

@deggis: A flywheel is only one way to store energy.

The new regulations pose significant engineering challenges and there are many options to store and use the energy, such as high speed flywheels, hydraulics, pneumatics or electric drives. The system must recover and store energy under braking, and then release the energy on command by the driver.

source: http://www.zytekgroup.co.uk/Default.aspx?tid=254

Electrical systems (like used in road cars today) are heavy: extra batteries, electro engines, etc. Replacing the batteries with supercondensators seems a good way to reduce weight.

You could also use a hydraulic solution (e.g., integrated in gearbox). F1 teams already have a lot of experience with hydraulics.

Willy Rampf of BMW already said they will use an electrical system. See http://www.formula1.com/news/intervi...08/2/7375.html

From reading the Autosport article on them, it seems only one team is looking at a non electrical system.

source: http://forums.autosport.com/showthre...18#post3000518

[Aysedasi]

Man this thread is far too light and flippant for me.........

[MGDavid]

there was a really good article on KERS in Racecar Engineering a few months ago - I found it easy to read and follow (and I'm not an engineer).

[yamato]

Wow! I had totally missed the bus on this. I had thought that F1 was talking about electrical systems that used a capacitor of sorts.

What effect will this have on cornering ability of the cars? There would seem to have to be an whole bunch of inertia stored in the flywheel for it to have an appreciable affect on the forward launch of the car. If so; what are the consequences of that large gyroscopic moment of inertia on the ability of the car to change direction?

It's been a long time since basic physics,...... or even engineering mechanics for that matter,.... something about conservation of angular momentum comes to mind??????

Who's the expert on this stuff here.

[gwyllion]

As I mentioned earlier, I doubt a lot of teams will use the flywheel solution. So perhaps we will never know.

[diffuser]

You're all using way too many technical terms. This is supposed to be for real dummies

[ss_collins]

The flybrid - this is the best publicised KERS and will be used in F1
http://www.racecar-engineering.com/a...s-flybrid.html

an earlier hydraulic concept
http://www.racecar-engineering.com/a...tic-racer.html

I'll put some more KERS content up this week

[Oldtony]

To try and keep the thing simple.
Kinetic energy is that energy required to halt or accelerate any mass(weight)
Every moving object has kinetic energy.
The amount is a factor of weight x speed.
To slow a moving vehicle brakes convert kinetic energy to heat through friction.
Kinetic Energy Recovery System aims to capture, store, and then re use some of that braking energy.
Basically there are 4 theoretical ways to do this:
1: Heat recovery: Recover some of the heat generated by braking and convert it to power. Heat exchanger? steam generator? Might be possible but unlikely.
2: Kinetic flywheel energy: As outlined in the Flybrid proposal. My concerns would be that the amount of energy stored would require either an engine speed flywheel of considerable weight, or a much lighter flywheel rotating at a multiple of engine speed. The snag then becomes the safety of the enclosure of the flywheel in the event of a failiure or of a structure deforming accident. If you have ever seen the results of a flywheel failiure in a race modified engine you would wonder where anything storing that much energy could finish up. The other concern is the gyroscopic effect, not sure if that might not cause significant handling problems. Try changing the direction of a heavy spinning object.
3: Hydraulic: Energy could be store by using it to compress a liquid (or gas) and then using that compressed fluid to regenerate torque. A very practical proposition but it would be most efficient if the torque could be generated at the wheel (or at least axle) and then the reverse cycle used to release the torque back through the same system. The very restrictive rules applied to KERS for F1 probably make that format impractical, or at least marginal when the pressure storage vessel wieght and location are taken into account. Probably best related to a four wheel drive soloution, and may be practical for LMP.
Electrical: The Prius solution. Braking generates electric power which is stored the reused later through the standard transmission. Usually a motor/generator inserted between engine and transmission. Problem with Prius type soloution is the wieght of batteries required for extended period storage of charge. In a racing situation the lengthe of time the charge needs to be held is short which opens the way to use super capacitors adapted to hold very large charges for short periods. This is the system used by Toyota in the Japan GT series Supra Hydrid, and seems to be the soloution that most F1 teams are developing.
Meanwhile of course a whole new technology is there for development. Any of the above principles, and even something out of left field altogether could become the favoured system
Pity FIA regs fo F1 are trying to strangle it at birth.

[gwyllion]

Originally Posted by Oldtony

1: Heat recovery: Recover some of the heat generated by braking and convert it to power. Heat exchanger? steam generator? Might be possible but unlikely.

Thermoelectric conversion could be an option, but it will be hard to turn heat onto electricity such a short period of time.

[gwyllion]

Originally Posted by Oldtony

Pity FIA regs fo F1 are trying to strangle it at birth.

Yeah. Toyota engine chief says KERS 'primitive'

[JimW]

Originally Posted by diffuser

You're all using way too many technical terms. This is supposed to be for real dummies

I'm afraid you are promoting a modern fallacy. Complicated technical matters cannot be simplified in the way you seem to want. This is known to scientists and engineers as "the journalistic fallacy".

Sad to say "real dummies" will just remain that - real dummies.

Regards

Jim

[JimW]

Originally Posted by Oldtony

2: Kinetic flywheel energy: . . . The other concern is the gyroscopic effect, not sure if that might not cause significant handling problems. Try changing the direction of a heavy spinning object.
. . .

The conventional way of dealing with this is to have two identical wheels spinning in opposite directions. There is then no net gyroscopic effect. (But there will be stresses in the axles of each wheel to be coped with.)

The points made about stored energy are very real. You are looking to achieve a very high stored energy density in a form easily turned back into kinetic energy. Both of those issues point to a potential for fast release (also known as an explosion!) if something goes wrong.

Regards

Jim

[yamato]

I see that the Flybrid solution goes to a light weight flywheel, but then they have to operate it at 60,000 rpm!!!!!!!

That is some serious spin,.....

My major question as well is; where will this be allowed? one at each rear wheel? one mated to the transmission?

Very interesting stuff.

It sure sounds to me that the technical folks at Toyota are ready to show off their system,.......

Though it appears that F1 will not be the place.

[ss_collins]

Flybrid will be in F1, a single unit mated to the transmission

[Oldtony]

Be good to see the development of solutoutions alternate to the electrical motor generator idea.
I think it will take some pretty fancy engineering to adapt the flybrid input/output control, and I am concerned about the safety of flywheels storing that much energy in a crash or failiure situation.
Roll on 2009. at last something of technical interest in F1 again.

[gwyllion]

http://www.autosport.com/news/report.php/id/66676

[gwyllion]

I am not convinced the flybrid solution matches very well with the 2009 F1 rules. I have the impression that it is mainly designed to store energy during braking and use it immediately afterwards when exiting the corner. So you can not store energy during a complete lap and recover it once on the straight with a press on the magical boost button. Electrical hybrids are better suited for the scenario FIA has in mind.

[Notso Swift]

High speed flywheel with low friction bearings in a vacuum will store energy for a long time.

Oh, and if the battery units can be charged in a few corners they will be fully cycling in a lap anyway

[Oldtony]

In the F1 forum the effect on next years racing of new regs is being discussed.
Some suggestions are made there about banning refueling, or limiting fuel.
Can anyone make any estimates of the level of fuel saving available from KERS under next years regs. and some estimate of what it could be give a free hand on energy recovery.
Could something like a 50% cut in fuel use while acheiving current lap times be achieved?

[bludvl_x19]

IIRC, in Race Tech mag they saythat there is a limit to the energy output of KERS per lap, methinks its 400KJ. I'll have a look for the mag when I go home from uni for the weekend, I know its there somewhere.

Mick

[R59]

Originally Posted by Oldtony

Some suggestions are made there about banning refueling, or limiting fuel.

That's the best news I've heard in ages, if it comes about.

[RotorFan]

About the gyroscopic effect the flywheel will have... The flybrid system does not seem to use two opposing flywheels, so there will be a gyroscopic effect whether its in pitch, roll, whatever. In the F1 forum jedrinck mentioned this could be used to good effect, to provide a stabilisation.

Whatever effect the flywheel has on the balance of the car, won't this make it undriveable since the speed of the flywheel will be constantly changing as it is charged/discharged? The balance of the car would be changing several times in a single lap!