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Passive turbo charger
Posted: 09 May 2012, 22:07
by HILTON
i know very little about aero or engineering like most of you on here but,
would there be any advantage of having a free spinning fan in the main air intake?
as the car speeds up it would spin the fan and potentially increase air and the opposite as it slows down into the corner thus not creating over run.
could this work or would it just create drag and or actually just block the air intake too much?
Re: passive turbo charger
Posted: 10 May 2012, 07:50
by wunderkind
HILTON wrote:i know very little about aero or engineering like most of you on here but,
would there be any advantage of having a free spinning fan in the main air intake?
as the car speeds up it would spin the fan and potentially increase air and the opposite as it slows down into the corner thus not creating over run.
could this work or would it just create drag and or actually just block the air intake too much?
probably not.
first, there will be more moving parts and hence weight and also the need to engineer larger sidepod cavities to house these fans (you need to maintain a certain volume for air to enter). Not good when larger intake cavity will increase drag.
secondly, the existing cooling system for modern F1 engines are sufficient and doesn't require more incoming air when the cars are in motion. If anything, the focus should be on how to expell the hot air from underneath the cowling efficiently and effectively.
Re: passive turbo charger
Posted: 11 May 2012, 08:26
by megz
Fans are banned entirely from F1 cars regardless. An interesting concept for outside F1 though.
Re: passive turbo charger
Posted: 11 May 2012, 17:36
by NGGrant
You have to be joking.. Like the "Turbonator" supercharging fan???
A passive fan on the intake would do nothing but block the airflow and steal power from the engine.
Just wait. Another 18 months an we will have real turbos.
Re: passive turbo charger
Posted: 11 May 2012, 21:23
by Tommy Cookers
With proper engine control the degraded induction could in part be compensated for by increasing the compression ratio at the piston.
If the fan was used substantially to benefit the track performance, it might be worthwhile.
Re: passive turbo charger
Posted: 12 May 2012, 02:20
by xxChrisxx
Tommy Cookers wrote:With proper engine control the degraded induction could in part be compensated for by increasing the compression ratio at the piston.
If the fan was used substantially to benefit the track performance, it might be worthwhile.
I'm interested to know what you and the OP believe this 'fan' would do exactly?
And the principle on which it would work.
Re: passive turbo charger
Posted: 12 May 2012, 20:03
by Tommy Cookers
No idea !
A fan car like the Brabham BT46B could work in this way; yes, I know it wouldn't be allowed. A fan car surely more efficient than 'modern' aero ?
F1 cars are very inefficient, because the rules make this so. Unlimited fuel/limited aero discourages efficiency.
The most efficient spark ignition engines use modern developments of the Atkinson or Miller cycles, ie the more complete expansion available when cylinder filling is less than maximal, and are technology appropriate to the subject of this thread.
Re: passive turbo charger
Posted: 13 May 2012, 03:17
by xxChrisxx
Tommy Cookers wrote:No idea !
A fan car like the Brabham BT46B could work in this way; yes, I know it wouldn't be allowed. A fan car surely more efficient than 'modern' aero ?
F1 cars are very inefficient, because the rules make this so. Unlimited fuel/limited aero discourages efficiency.
The most efficient spark ignition engines use modern developments of the Atkinson or Miller cycles, ie the more complete expansion available when cylinder filling is less than maximal, and are technology appropriate to the subject of this thread.
I'd like to point out that this thread is based on very poor
A fan moves large amounts of air at low pressure, and high velocity.
A compressor moves a bit of air at low velocity and increases pressure.
For an engine intake, you want a high pressure differential between intake and cylinder, as that's what makes a cylinder fill up.
Sticking a fan in the way will do no useful work, and will impede flow and actually remove energy. As you are sapping energy from the air you are trying to use.
Re: passive turbo charger
Posted: 13 May 2012, 13:09
by Tommy Cookers
I was just trying not to rain on the thread originator's parade, by pointing out the scope for reducing the 'obvious' downside of his suggestion.
Are you rejecting the view that a spark ignition engine can have a higher nominal compression ratio if its induction is less than maximal, and therefor a higher real expansion ratio, and higher efficiency ?
Talking of wasted energy, you are refuting things that were not said (by anyone).
Re: passive turbo charger
Posted: 13 May 2012, 13:30
by tommylommykins
Does this sound like a perpetual motion machine?
Placing a free-spinning fan in a tube of air will only cause it to slow down, not speed up. The degenerate case is to imagine a doughtnut shaped ring-tube with a fan inside. According to this idea, the fan would speed up the air, which would speed up the fan, which would speed up the air, on and on and on.
Re: passive turbo charger
Posted: 13 May 2012, 14:01
by xpensive
HILTON wrote:i know very little about aero or engineering like most of you on here but,
would there be any advantage of having a free spinning fan in the main air intake?
as the car speeds up it would spin the fan and potentially increase air and the opposite as it slows down into the corner thus not creating over run.
could this work or would it just create drag and or actually just block the air intake too much?
I think I get your drift, but I'm afraid although the your free-spinning fan will increase its rpm on the straights, it will still slow down the air speed to less than car-speed, but as the car slows down in the corner, the fan's inertia should in theory increase the air-speed to more than car-speed, correct?
Re: passive turbo charger
Posted: 17 May 2012, 07:57
by SBR9
Re: passive turbo charger
Posted: 17 May 2012, 16:35
by munks
OMG, perfectly timed article, that's hilarious!