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Locost (KERS) Energy Recovery Systems (ERS)
jossey - 13/3/14 at 06:08 PM

Would it be possible to develop KERS for a Locost build?

Dave


tegwin - 13/3/14 at 06:14 PM

Anything is possible...Just depends on your budget and skills!


steve m - 13/3/14 at 06:46 PM

locost version would be a big hole in the floor, flintstone way


bi22le - 13/3/14 at 08:19 PM

You could try and do it in a very simple way.

Get your starter motor and split the solenoid and cranking supplies to be sepperate. To activate KERS (during braking) engage the solenoid which kicks the starter into the fly wheel. A little bit of clever electronics bottles the electricity generated.

To get it back. . . . . .

Well its not just as simple as kick the starter back in again, it does not spin faster enough. Maybe have another on the drive shaft?


luke2152 - 13/3/14 at 09:22 PM

What about a supercharger turned by a powerful electric motor. And a large battery and very uprated charging system. Could make lots of boost on demand for a few seconds at a time


owelly - 13/3/14 at 09:23 PM

Thinking outside the box:
Fit a compressor on the propshaft with an electronic clutch operated by the brake pedal. A couple of lightweight carbonfibre air cylinders to store the compressed air. Then a solenoid operated by a switch under the accellerator and on the steering wheel to run the compressor as an air motor.
So, during braking, the compressor charges the air cylinders. When you want to use the stored energy, hit the throttle and poke the button on the steering wheel. KISS.


43655 - 13/3/14 at 10:50 PM

Superchargers take like 50hp to run, any electric motor that can run that would be so big and heavy it would completely negate the original intention.
The new red bull f1 promo video has 2 different kers methods, worth checking out.
Oh and not sure a starter would work, trying to engage with a 6000rpm flywheel!


luke2152 - 13/3/14 at 10:57 PM

quote:
Originally posted by 43655
Superchargers take like 50hp to run, any electric motor that can run that would be so big and heavy it would completely negate the original intention.
The new red bull f1 promo video has 2 different kers methods, worth checking out.
Oh and not sure a starter would work, trying to engage with a 6000rpm flywheel!

Centrifugal supercharger is pretty efficient. Something like a washing machine motor geared appropriatly might do it


bi22le - 13/3/14 at 11:20 PM

quote:
Originally posted by 43655
Superchargers take like 50hp to run, any electric motor that can run that would be so big and heavy it would completely negate the original intention.
The new red bull f1 promo video has 2 different kers methods, worth checking out.
Oh and not sure a starter would work, trying to engage with a 6000rpm flywheel!


who said the starter can not be primed with speed to ease meshing.


coozer - 13/3/14 at 11:46 PM

The 125cc gp bikes had a big capacitor that was charge by the generator on the overrun (braking), and once back on the throttle the cap drained back into the generated turning it into a motor to help acceleration.

Problem for our cars is the dual genny/motor bit.

We would need to find a way to turn the flywheel into that dual setup.

I think we are hand tied until there is a feasible donor.


coyoteboy - 14/3/14 at 12:40 AM

The control electronics and mechanics required to do all of this would be prohibitive.
Super high speed flywheel storage would be easier to work but still an absolute nightmare.

Put your cash into shares in bp, you will return more as fuel runs out and prices rocket.


Surrey Dave - 14/3/14 at 12:57 AM

What about an auxiliary steam engine, using the heat from the brakes and exhaust to boil the water?

Should go like a 'Rocket'


S2kPower - 14/3/14 at 07:49 AM

quote:
Originally posted by coyoteboy
The control electronics and mechanics required to do all of this would be prohibitive.
Super high speed flywheel storage would be easier to work but still an absolute nightmare.

Put your cash into shares in bp, you will return more as fuel runs out and prices rocket.


90% of the oil we're using now was discovered in the 60's/70's

You'll be waiting many many years before oil runs out


hughpinder - 14/3/14 at 11:27 AM

Probably easiest to charge batteries/capacitors from the engine/any other energy recovery system you set up and then run an electric motor, say like this one wich weighs 40kg and delivers 200 bhp:

http://www.400hertz.net/Products/ME-400-200-416.htm

You would need some form of battery monitoring that started/stopped/adjusted the speed of your petrol/diesel motor to match the battery drain rate and battery current charge, with enough battery capacity that you never charge above your maximum energy recovery rate.

Regards
Hugh


jossey - 14/3/14 at 11:44 AM

I like the idea. :-)


quote:
Originally posted by hughpinder
Probably easiest to charge batteries/capacitors from the engine/any other energy recovery system you set up and then run an electric motor, say like this one wich weighs 40kg and delivers 200 bhp:

http://www.400hertz.net/Products/ME-400-200-416.htm

You would need some form of battery monitoring that started/stopped/adjusted the speed of your petrol/diesel motor to match the battery drain rate and battery current charge, with enough battery capacity that you never charge above your maximum energy recovery rate.

Regards
Hugh


Irony - 14/3/14 at 02:12 PM

Seems to me it's quite easy to take energy out of the system during braking etc but putting that energy back into the system at the right time and in the right form is the hard part.


S2kPower - 14/3/14 at 02:45 PM

I think every stage is very difficult

Look at the F1 testing

Grojean nearly went off the track due to the issues actually harvesting the energy from the braking system.

It's the additional braking effort applied by whatever is harvesting the energy that needs to be predictable and usable that really needs sorting. Putting the energy back in is just time and money as, generally speaking, you make a connection with part of the drive train and boost

Take the example of heel toe. Some people can't maintain a consistent brake pressure so end up braking earlier just so they can blip the throttle. A little rear end instability for them is actually quicker as they can brake later. Same applies for regenerative braking. That level of calibration will take quite a while and I'm betting the braking effect of the harvesting won't be linear with the brake pads

That's my 2 cents anyway!


coozer - 14/3/14 at 04:59 PM

What about one of those homemade axial flux generators that the windmill nerds make? Bolt it to the diff flange and charge a big super cap....

[Edited on 14/3/14 by coozer]


Toltec - 14/3/14 at 08:29 PM

Using a Prius drivetrain would be too obvious?


jkarran - 2/6/14 at 12:11 PM

Unless you're really rather handy with the electrics including programming the controller you're going to struggle to do much more than add weight and fire.

The transient power input to the braking system is huge, to recover that energy usefully requires a generator set that can handle the power so heavy and simple or very well cooled, a controller that can handle 100kW++ which is no mean feat and an energy store that can absorb/dump energy at that rate, if it's a battery it'll be LiPO and 5kWH+ so not cheap and a nasty fire risk. There are other options but none are cheap and simple. DC generator sets won't drive efficiently (DC drive won't generate efficiently) so you're realistically looking at 3phase motor/generators which are orders of magnitude more involved to control. Unless your vehicle is electric or a strong (electric biased) hybrid to begin with this is a lot of additional weight, cost and complexity for very little gain.

Contra-rotating high speed flywheels driven/driving via a CVT under computer control look the best bet for 'bolt-on' KER but it's hardly locost home-builder territory until they start turning up as complete modules on a diff in scrap yards.

Adding it one end only also means your brake bias will be all over the place if you're extracting meaningful amounts of energy.

jk


coyoteboy - 3/6/14 at 09:42 AM

Anything is possible. That doesn't mean it's sensible for joe bloggs and his garage unless joe bloggs is actually a fairly high flying engineer and has a lot of equipment and skills at his disposal.

Harvesting power has the potential to lock wheels on braking.
Harvesting power requires mechanical linkages to the driveline that need to be unlikely to fail and cause catastrophic lockup.
Harvesting power has to happen across the power and speed range to be useful.
Dumping power requires tight control.
Dumping power requires powerful motors or flywheel storage with correct gearing.
Storing power requires either evacuated flywheels or batteries, or compressed gases. None of those are light AND cheap.
Some of those affect handling. If you can't put numbers on the effect, you're potentially screwing up the handling anyway.

One option would be to block the exhaust at the mani and harvest the pumped gases on over-run, dumping that back into driving a turbo or a pneumatic motor. Hard to quantify the stress on the engine though and would require electronic throttle control to maintain open throttle on over-run.

[Edited on 3/6/14 by coyoteboy]


whitestu - 3/6/14 at 02:13 PM

quote:

What about one of those homemade axial flux generators that the windmill nerds make




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