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can anyone show me an underbody fan that is coupled with a full ground effect underbody and ground effect sidepods. please show me a design with that included. or can anyone design a caar with that included




thought it would be a fun concept !!!

Wouldn't a fan simply disrupt the airflow that allows a full underbody ground effect design to function? One would surely disrupt the other, making this an exercise in futility?

do a search for chaparral race car. they invented it decades ago. i'm not sure if some one in f1 tried to copy it and were banned??

Take a look...

http://lmgtfy.com/?q=brabham+bt46b

brabham bt46b

Also it is not real:

http://eu.gran-turismo.com/gb/news/d36531.html

The ground effects cars we know of, typically the Lotus 79, created a low pressure zone under the car by careful management of the airflow.



It was an elegant, refined design that paid respect to the laws of aerodynamics and airflow.

But as soon as you hang a fan off the car to extract air from under the car and create negative pressure, there's nothing elegant about it, it's just a box operating under brute force.



Therefore, if you decide to use the fan and suction method, you don't need the elegant and beautiful sidepods or carefully shaped underbody. You just put on skirts to seal the sides, crank up the fan, and go.

I know ta link was posted already, but here is the design thoughts for the Red Bull X1 concept...

adriannewey9864 wrote:can anyone show me an underbody fan that is coupled with a full ground effect underbody and ground effect sidepods. please show me a design with that included. or can anyone design a caar with that included thought it would be a fun concept !!!

I'm not an aero expert, but does using a powered fan to extract air from a duct still technically qualify as a "ground effect"? My understanding of ground effect implies a passive aerodynamic device. Skirts, tunnels and diffusers, but not fans.

You are right. In order to minimise the power consumption of the suction fan you want to minimise the leakage, and hence airflow under the car. So the ground effect wouldn't work at all, ideally.

For me it would make sense to couple a fan AND ground-effect.
The fan can provide larger downforce at lower speeds until the aerodynamic flow takes over and at higher speeds you can use the not needed fan-power to reach higher top speeds.

If I remember correct, Colin Chapman sketched a Lotus 79 coupled with a fan after the Swedish GP 79.

Another idea: Could you try to reverse the fan in order to disturb the airflow under the car in order to shed off drag?

matt21 wrote:For me it would make sense to couple a fan AND ground-effect.
The fan can provide larger downforce at lower speeds until the aerodynamic flow takes over and at higher speeds you can use the not needed fan-power to reach higher top speeds.

If I remember correct, Colin Chapman sketched a Lotus 79 coupled with a fan after the Swedish GP 79.

Another idea: Could you try to reverse the fan in order to disturb the airflow under the car in order to shed off drag?

The suction effect the fan creates, generates only very little drag, if any at all. Therefore, reversing the fan will only ensure that you have lift, making breaking alot more difficult because the airflow does not reattach itself inmediately.

That's the beauty of ground effect and the fan: it generates massive amounts of downforce at practically no relevant drag penalty, making it none-compromise solutions in terms of aero set up. It even allows you to reduce downforce in more draggy areas. I've seen videos from ground effect cars driving around at Monaco without starting with a front wing.

isn't passive aero (in a race car) inherently less efficient than a fan ?

surely the logical step beyond the fan cars as made was to route substantial engine power to the fan(s) when needed for cornering ?
surely 10g cornering (and braking) is possible this way ?
10g (cornering and braking) is physiologically tolerable circulationwise (re 'blackouts'), good neck braces would be needed ?

Tommy Cookers wrote:isn't passive aero (in a race car) inherently less efficient than a fan ?

surely the logical step beyond the fan cars as made was to route substantial engine power to the fan(s) when needed for cornering ?
surely 10g cornering (and braking) is possible this way ?
10g (cornering and braking) is physiologically tolerable circulationwise (re 'blackouts'), good neck braces would be needed ?

Yes it is much less efficient to generate downforce via ground effect than with a fan. Why else do you think they banned fans?

If you want a serious discussion of this, work out the power required when generating 4g downforce at top speed. L/D for ground effect with skirts is about 10. It is easier than you think.

Or of course we could waffle on and on and on and on and on without any numbers. But lots of hand waving. Because they could rename this board F1handwaving for all the technical discussions that take place.

Greg Locock wrote: Yes it is much less efficient to generate downforce via ground effect than with a fan. Why else do you think they banned fans?

If you want a serious discussion of this, work out the power required when generating 4g downforce at top speed. L/D for ground effect with skirts is about 10. It is easier than you think.

Or of course we could waffle on and on and on and on and on without any numbers. But lots of hand waving. Because they could rename this board F1handwaving for all the technical discussions that take place.

Greg Locock,

I might argue that using an engine-driven fan to create downforce by scavenging air from the underbody would only be more "efficient" under certain conditions. For sure it would help in low speed corners. But on high speed straights the engine power diverted to drive the fan would hurt top speeds. Before fans were banned, I believe the designers were using variable speed drives precisely for this reason.

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