KERS flywheel in the nose of the car?

[zac510]

If a flywheel is in the nose, while laying horizontally, would it help to stabilize the up and down pitch movement?

hmmm.... that sounds like an 'aerodynamic device' !

[bazanaius]

Random question about KERS - do they have to apply the kers at 60kw, or can they 'dumb it down' but run it for longer - say 30kw for 13.4s? Not sure whether this would be useful, just trying to clarify rules.

Maybe if this is the case they can adjust it for each corner - take it as an energy problem rather than a power one and optimise over a lap given track conditions or whatever other variables they might want.

B

[Professor]

A basic mechanical problem with the flywheel in the nose is how do you couple it to the freaking drivetrain? It must be driven by a mechanical system. To concern one's self with the cables ignores the mechanical connections. How do you connect it mechanically?

The Williams drum flywheel is mounted vertically and it is driven off the front of the engine. This puts the weight close to the CoG. It rotates clockwise when viewed from above. The basic gyro effect is directionally neutral. The gyroscopic action doesn't seem to be an issue to me. It would add stability to the car and would seem to inhibit the tendency to yawl when changing directions.

True, to some degree it would resist directional changes when cornering, but the effect is minimal when compared to the mass of the car at speed and the forces involved.

[Professor]

Random question about KERS - do they have to apply the kers at 60kw, or can they 'dumb it down' but run it for longer - say 30kw for 13.4s? Not sure whether this would be useful, just trying to clarify rules.

Maybe if this is the case they can adjust it for each corner - take it as an energy problem rather than a power one and optimise over a lap given track conditions or whatever other variables they might want.

B

They can do what you suggest. The rules limit the maximum output, but do not limit its use otherwise. Using the system to stretch the pit window via fuel conservation rather than an increase in total power is a strategy that could be employed.

[Professor]

thanks for the explanation... still trying to get my head around it though.

On a side note, if such a system were in place, theoretically would the gyroscopic forces be able to 'hold' the car in midair after it goes over a curb/bump momentarily? In practice, I assume the downforce would counter that if it were the case though.

If the gyrscopic forces were powerful, it would inhibit the chassis from rolling and pitching, but have zero efect if the motion was straight up and down.

One additional handicap is the added weight of the electrical cables. They would have to carry high amperage, which would make them large gauge. Such large gauge copper wire would add up in the weight department. For instance, 10 ga. copper is 31.8 feet per pound. So roughly, expect adding at least 2 kilos for wire if you intend to run it to the nose. Considering engineers sweat the fine details just to remove a gram here and there, and this makes for a difficult decision.

Are you guessing at the amperage requirements of the Williams KERS system, or do you have some actual information leading to your dismissal of this idea? I have seen some rather large machinery that uses 480v 3phase, and run on 8 gague wire over a 150ft run.

I think for the 10 feet or so that would be needed, 10/3 aluminum MC cable should be fine.

Unless, of course, you actually have some amperage numbers from WIlliams?

Also: Why would it slice the drivers feet? It is a fully enclosed, vacuum sealed "disc" casing. Even in the event of catastrophic failure, I believe that Williams claims 100% containment.

The question is: Would it be advantageous to place the flywheel low and in the front (nosecone, or under the drivers feet) to control pitch? Or would its placement be necessitated by the pitch center of the car?

Thanks!

See my post above about putting a mechanical device in the nose.

The systems operate at about 300 volts DC. Watts divided by volts equals amps. So, if 60 kw is the mandated max output of the system, then 60,000w/300v = 200 amps. This requires a wire of 3/0 copper cable per the NEC. Big cables, guys. Not a number 10 aluminum which is rated for only 25 amps. Do the math.

The three phase example is an AC application. Battery systems are DC. One hot only and a neutral. Three phase has three hots. The equation for three phase is watts/volts*1.732. The 1.732 is the square root of three and is a constant in all 3 phase calculations. So, your example is irrelevant to this discussion.

By comparison, 60,000 w/480*1.732 = 72 amps. With aluminum wire this would require a #2. But, not relevant at all to a DC system.

One does not need to know Williams data to do this calc. One only needs to know the maximum allowed output of the system. You guys must be mechanical engineers judging by your understanding of electrical systems.

[Professor]

Another point about the distance from the source to the load: Voltage drop is based on the resistance per foot of the conductor. The calc is a constant * the load amps * the distance * 2/ by the cross sectional area of the cable.

So, short cable ampacities do not have to be adjusted for length, but long cables do. The practical rule of thumb is that there will be no voltage drop if the applied voltage is = to .5 * the length of the cable.

The distances involved in F1 cable is well within this parameter.

[Professor]

Sorry to be such a bore, but I cannot comment on aero or many mechanical things, so I launched on a subject I know. I am not a pedant. Just eager to share something that I know, and what I know seldom has any relevance to the sport I love, F1.

[avatar]

Similar fylwheel KERS affects on handling are discussed here:
viewtopic.php?t=5981

I don't know the gyro loads that could be generated from the FIA restricted capacity of KERS, but maybe 2 flywheels could be mounted in such a way to increase/decrease torsion in the chassis/suspension components & side-step into active suspension?

Also, on the nose mounted flywheel, I'd guess it may be banned on safety grounds (unless the flywheel unit has tethers like the wheels), as in a high-impact collision, if the unit (i.e. flywheel still in it's enclosure, but detached from the chassis) was loose, it could cause a fair bit of damage, both due to it's mass, and the gyro effects possibly making it spin wildly each time it changed direction....

p.s. the KERS drive train needn't be pure mechanical/ electro-mechanical, why not fluid/hydraulic transmission?

Will

[PlatinumZealot]

Hydraulic?

tank > turbine > hoses > then a hydraulic motor > tank ?

There are some implications to using hydraulics though.

viewtopic.php?f=11&t=6423

[alelanza]

A basic mechanical problem with the flywheel in the nose is how do you couple it to the freaking drivetrain? It must be driven by a mechanical system. To concern one's self with the cables ignores the mechanical connections. How do you connect it mechanically?

AFAIK the Williams implementation uses no mechanical linkage to the flywheel,it's all electrical.