19 replies to this topic

[Thrasher]

I was thinking about how F1 cars have no fan for cooling because of wieght, space, and it takes power from the engine. I had a thought about using a turbocharger which would not force air into the cyclinders. Instead the output air from the turbo would be directed to flow over the radiators. This would provide airflow even when the car is not moving. My question is, would this system actually work or what would be the benefits or problems with this system, compared to standard cooling systems. This wouldn't have to only apply just Formula 1 cars, but to any racing cars or even street cars?


Another idea I had is to attatch a electric generator to the shaft of the turbo. I was thinking that even a really small motor with a low amount of mechanical rotating resistance could produce a lot of electricity given that turbos spin at like 80,000 rpm. I don't think it would draw as much energy power from the engine as a standard alternator does. But could a generator like be useful for powering ignition or other electronic systems? What other problems are there with this idea?

[Canuck]

Without any nod towards charge-cooling, the biggest problem I see is blowing hot compressed air all over the radiators. Intead of cooling them, you may well be heating them. Any charge cooling short of spraying an intercooler with water/alcohol/N2O will have the same lack-of-airflow problem at low speeds and any charge cooling system will result in increased weight/cost.

I suppose you could configure an exhaust-driven fan that didn't compress (heat) the air.

[Greg Locock]

I worked on a turbo-alternator, many years ago. They increase the inertia of the turbine, which is a bad thing, and the weight on the exhaust manifold, and the alternator gets hot, but, by and large, those are all solvable problems.

As to efficiency, well, current alternators aren't very efficient, but only because it is not worth making them more efficient. If we had to the technology is there for >90% efficiency.

[Ben Wilson]

Originally posted by Thrasher Another idea I had is to attatch a electric generator to the shaft of the turbo. I was thinking that even a really small motor with a low amount of mechanical rotating resistance could produce a lot of electricity given that turbos spin at like 80,000 rpm. I don't think it would draw as much energy power from the engine as a standard alternator does. But could a generator like be useful for powering ignition or other electronic systems? What other problems are there with this idea? [/B]

Trying to find an impeller small enough to spin at idle which doesn't cause restriction at high revs seems problematic to me,

[Catalina Park]

Alternate use for turbos

[zac510]

Originally posted by Greg Locock

As to efficiency, well, current alternators aren't very efficient, but only because it is not worth making them more efficient. If we had to the technology is there for >90% efficiency.

Is there no chance to make a net gain using an electric a/c, electric water pump, elec power steering, etc?

[Moon Tricky]

I once read an article about using a turbine to generate electricity for a truck. I think it was plenty to power the electrical systems, 5kW or so. You can also drive the generator as a motor to increase the response speed of the turbo.

If it doesn't spin fast enough at idle, could some sort of over-running clutch be used to connect it to the driveshaft?

[Greg Locock]

zac, sadly in production cars it always comes down to cost benefit. The cost benefit in going to a 90% efficient alternator is negative.

There is a net gain, but the people who buy the cars won't pay what we think it has cost us to fit it.


That said, electric PAS, water pumps etc will come in, as fuel prices increase.

Of course the biggest problem we face is the death of the 42V initiative. Can't really wrap my head around that one, it seemed like a good move!

[Andy Donovan]

Originally posted by Greg Locock
Of course the biggest problem we face is the death of the 42V initiative.

Which, for the ignorant amongst us, was what?

[phantom II]

If you could, what conclusions would you draw? Not long ago, I predicted that within a decade, cars would have 24v systems.

Originally posted by Greg Locock
Of course the biggest problem we face is the death of the 42V initiative. Can't really wrap my head around that one, it seemed like a good move!

[Todd]

I could swear I read an article where they said that any number of safety issues like arcing arose from having 42 volt systems in cars. 12 volt systems don't pose many safety hazards away from the ignition coil, other than skin irritation from handling batteries, while 42 volts was enough to make any circuit on the car a potential hazard, and arcing from the battery terminals a real possibility. Extreme care would need to be taken to connect or disconnect a 42 volt battery, and you'd have to be a loon to assume that lawyers would allow for that.

[Thrasher]

Originally posted by Canuck
Without any nod towards charge-cooling, the biggest problem I see is blowing hot compressed air all over the radiators. Intead of cooling them, you may well be heating them. Any charge cooling short of spraying an intercooler with water/alcohol/N2O will have the same lack-of-airflow problem at low speeds and any charge cooling system will result in increased weight/cost.

I suppose you could configure an exhaust-driven fan that didn't compress (heat) the air.

I had thought this might be the biggest problem with my idea. I'm not really sure what sort of tempurates the turbo air would be at but even so, wouldn't the amount and speed of the air help at all, even it it isn't cool air to begin with? Adding an intercooler would basically cancell out any benefits of this system becasue of weight and such

Just curious, is there any video that shows just how much airflow is made by a turbocharger? I'm thinking some sort of demonstration where the turbocharged air would be run through a pipe pointing outside the car and made to blow on something big and heavy and knock it down

[Greg Locock]

42V was an industry wide attempt to move to a higher voltage for the electrical systems in the car.

Todd's quote sounds a bit alarmist. The reality is that you can kill yourself with three car batteries in series (the 42V was really 36V to anybody with self respect), but you have to try pretty damn hard.

The advantages of 42V were that currents were reduced, so wire sizes would drop, so weight and cost would drop.

The problem was that many systems have been optimised around 12V, in particular I vaguely remember that light bulbs were a partiuclar issue, and would have needed down-converters. On the up side, all the electric motors would be lighter and, possibly, cheaper. Switchgear would need a redesign, basically 12V is so pathetic that it works underwater

I suppose battery cost and packaging /might/ have seemed like an issue, but really it would be a 12V battery cut in thirds, and then welded back together - not really a terrible tear up.

random googling came up with the following

http://www.powermana...ement/199201775

which is rather good.

[ray b]

I to have thought of turbo powered accesserys
but with hyd rather then direct drive as hyd systems are eazy to store power
via compressed air in the hyd oil tank
and no need to pass all the exhaust gas thur the turbo all the time
so a small bleed at higher RPM but total flow at idle
should meet the power needs of water pumps, fuel pumps alt , PS , vacume or air pumps or what ever
and no flow at all when accelleration is needed from idle to a preset value RPM
just run off the tank accumulated reserve

side note if compressed air is semi decompressed it self cools
so if air is boosted to say 40psi run thru a mini intercooler and then allowed to expand to 10 psi
I would think the heat problem goes away mostly
esp if air is used to move outside normal pressure air in a venturi effect
so the semi hot air diluted futher

stupid idea [maybe]
if you compressed air and intercooled it,
then allowed the flow to expand to normal 14.7 pressure
how much denisity would you gain?? enuff to add real power gains?

[Bill Sherwood]

If you're going to use a turbine wheel to run an alternator/generator, why not just use the existing one and add the appropriate electronics around either the compressor or turbine wheel, rather than add a turbine wheel further down the gas path.

[Andy Donovan]

Originally posted by Greg Locock
42V was an industry wide attempt to move to a higher voltage for the electrical systems in the car....The advantages of 42V were that currents were reduced, so wire sizes would drop, so weight and cost would drop.

Thanks for the link Greg, once again a visit to the tech. forum has taught me something new. I hadn't though of the lower current, thinner wires aspect for one thing.

[cheapracer]

Originally posted by Andy Donovan
Thanks for the link Greg, once again a visit to the tech. forum has taught me something new. I hadn't though of the lower current, thinner wires aspect for one thing.

Never worked on a Volkswagon eh? (6V wiring is huge)

[desmo]

Originally posted by Greg Locock


The advantages of 42V were that currents were reduced, so wire sizes would drop, so weight and cost would drop.

From a car owner's perspective, that seems like a pretty meager upside for presumably obsoleting all existing electronics. How much real net cost and weight reduction are we talking about for a typical mid-size sedan?

[phantom II]

There was talk of hybrid 12/42 volt systems also. Not a word anymore about it. It must be something to do with communism. Have you noticed that many words have disappeared from the worlds left wing anti- Christian pro-Muslim media. The mention of "Soul" and 42v is never mentioned anymore. Mmmmm.

[J. Edlund]

Originally posted by Thrasher
I was thinking about how F1 cars have no fan for cooling because of wieght, space, and it takes power from the engine. I had a thought about using a turbocharger which would not force air into the cyclinders. Instead the output air from the turbo would be directed to flow over the radiators. This would provide airflow even when the car is not moving. My question is, would this system actually work or what would be the benefits or problems with this system, compared to standard cooling systems. This wouldn't have to only apply just Formula 1 cars, but to any racing cars or even street cars?


Another idea I had is to attatch a electric generator to the shaft of the turbo. I was thinking that even a really small motor with a low amount of mechanical rotating resistance could produce a lot of electricity given that turbos spin at like 80,000 rpm. I don't think it would draw as much energy power from the engine as a standard alternator does. But could a generator like be useful for powering ignition or other electronic systems? What other problems are there with this idea?

1. F1 cars doesn't use cooling fans since they are prohibited.
2. Turbochargers are compressors, not fans or blowers. They are not suitable for delivering a large flow at low pressure (as that would result in choke), but a high pressure at low flow.
3. The flow of a large racing turbo is rarely higher than 1 kg/s, a 16" cooling fan can usually provide more than 1 kg/s. The turbocharger, if operating with a flow of 1 kg/s (70% efficiency) and a pressure ratio of say 3:1 it will consume approx. 150 kW, the fan is good with 350 Watt.
4 Electric motors/generators have been fitted to turbochargers in the past. These are usually designed to provide a "boost" at low speed while the act as a generator when the turbine is producing excess power. The motor/generator is typically rated a few kW. Google garrett e-turbo and you should find some info.

Originally posted by Todd
I could swear I read an article where they said that any number of safety issues like arcing arose from having 42 volt systems in cars. 12 volt systems don't pose many safety hazards away from the ignition coil, other than skin irritation from handling batteries, while 42 volts was enough to make any circuit on the car a potential hazard, and arcing from the battery terminals a real possibility. Extreme care would need to be taken to connect or disconnect a 42 volt battery, and you'd have to be a loon to assume that lawyers would allow for that.

I don't think safety is such a huge problem considering that most hybrid cars today are fitted with batteries providing much more than 42V. The main issue with the 42V system is probably that all equipment today is made for 12V, so if a switch is going to be made we need either a 42/12V system or a whole lot of new electric equipment.