RE: Ariel's 'fan car' explained
Discussion
The problem, as i'm sure they have already found out is not what happens when you can generate extra downforce but what happens when you suddenly can't!
Hit a bump that collapses the vacuum and suddenly you're going 50% too fast for the corner you were previously ok with. No point, braking, steering or doing anything else, possibly time to grab you belts and giving them a quick tug to tighten, because you'll be needing them in a second or two........
Hit a bump that collapses the vacuum and suddenly you're going 50% too fast for the corner you were previously ok with. No point, braking, steering or doing anything else, possibly time to grab you belts and giving them a quick tug to tighten, because you'll be needing them in a second or two........
SystemParanoia said:
Ozzie Osmond said:
One wonders why Ariel feel it's a good idea to adopt this ancient technology. When you're cornering flat out, clip a kerb and lose suction the car is immediately out of control and beyond recovery, heading to the scene of a big accident. AFAIK no race series on the planet allows it.
then dont clip the kerb.. you'll go round the corner faster that way.adapt your driving to the car you're in. easy really
yey lots of grip........ooops bump/pot hole/grating/etc suddenly my downforce has reduced by 80%
Clipping a kerb is probably over egging the problem, but it would be very real.
SlimJim16v said:
Don't think it's practical, especially if used on the road. As has been said, imagine losing the suction on a corner.
Maybe there's a way to get some of the benefit without the skirt?
The McLaren F1 road car did use two fans to reduce underbody pressure but obviously no skirts.Maybe there's a way to get some of the benefit without the skirt?
However, this car has been known to exit into the scenery backwards on bumpy uk roads and this might be a factor.
Max_Torque said:
The problem, as i'm sure they have already found out is not what happens when you can generate extra downforce but what happens when you suddenly can't!
Hit a bump that collapses the vacuum and suddenly you're going 50% too fast for the corner you were previously ok with. No point, braking, steering or doing anything else, possibly time to grab you belts and giving them a quick tug to tighten, because you'll be needing them in a second or two........
And what happens when you're actually moving and suddenly have a lot of edge leakage to content with when your 100mm fans can't shift enough near enough volume...Hit a bump that collapses the vacuum and suddenly you're going 50% too fast for the corner you were previously ok with. No point, braking, steering or doing anything else, possibly time to grab you belts and giving them a quick tug to tighten, because you'll be needing them in a second or two........
Still, great PR for a couple of industrial fans, flat sheet and some rubber door trims.
JackManny1 said:
Monkeylegend said:
stuart-b said:
So what happens when it sucks up all the stones and s
t on the ground?
Nice idea, but not practical.
You wouldn't want to be driving behind one when the fans kick in.t on the ground? Nice idea, but not practical.
Can you imagine the tantrums on a track day, after ArielBoy shot-blasts everybody else's cars?
Mind you, it'll be nothing compared to that superheated steam rocket's owner trying to explain why everybody else has horrific scald injuries.
Gary C said:
The McLaren F1 road car did use two fans to reduce underbody pressure but obviously no skirts.
However, this car has been known to exit into the scenery backwards on bumpy uk roads and this might be a factor.
I don't remember anything about the fans. I think not having any electronic driver aids might have had something to do with it.However, this car has been known to exit into the scenery backwards on bumpy uk roads and this might be a factor.
Edited by SlimJim16v on Wednesday 21st September 01:26
stuart-b said:
So what happens when it sucks up all the stones and st on the ground?
Nice idea, but not practical.
Gordon Murray said f1 drivers moaned about the Brabham's fan firing debris at them.t on the ground? Nice idea, but not practical.
Apparently, due to the shape and number of blades, debris doesn't get expelled along the rotational axis of the fan. If at all, it comes out radially, or more precisely, tangentially (allegedly).
That said, I couldn't even see the fans on the Ariel. They certainly aren't out back like the Brabham or Chaparral 2J, so it may be less of an issue.
If the fans aren't directly open to the air and their exhaust is ducted or vented away, debris is less of an issue.
Plus, we're all assuming that the pressures involved are sufficient to make it function like a giant vacuum cleaner, which may not be the case at all.
I can't help but to think that better underbody design on a vehicle with strategically placed Venturis on the upper body, allied to a splitter, diffuser and canards etc. could begin to produce ground effect without the need for powered active aero.
That said, the Atom doesn't really provide much scope for any of those.
Still, it's nice to see any company publicly experimenting with different, unusual or unpopular ideas. Especially a British company.
SlimJim16v said:
Gary C said:
The McLaren F1 road car did use two fans to reduce underbody pressure but obviously no skirts.
However, this car has been known to exit into the scenery backwards on bumpy uk roads and this might be a factor.
I don't remember anything about the fans. I think not having any electronic driver aids might have had something to do with it.However, this car has been known to exit into the scenery backwards on bumpy uk roads and this might be a factor.
Edited by SlimJim16v on Wednesday 21st September 01:26
While the driver aids thing I'm sure didn't help, it would be interesting to know how much the downforce from the fans and diffuser reduced on a bump
Gary C said:
SlimJim16v said:
Gary C said:
The McLaren F1 road car did use two fans to reduce underbody pressure but obviously no skirts.
However, this car has been known to exit into the scenery backwards on bumpy uk roads and this might be a factor.
I don't remember anything about the fans. I think not having any electronic driver aids might have had something to do with it.However, this car has been known to exit into the scenery backwards on bumpy uk roads and this might be a factor.
Edited by SlimJim16v on Wednesday 21st September 01:26
While the driver aids thing I'm sure didn't help, it would be interesting to know how much the downforce from the fans and diffuser reduced on a bump
Ive talked about fan-assisted traction in the past on normal cars, and people rubbish the idea as cars have clearence that is far too high and it just wont work..
but looking at the macca F1
Its not exactly a rizzla papers width from the floor is it... meaning fans can work even with large clearances.. just with diminishing effectiveness rather than just binary works / doesnt work ?
Heres a corvette modified to use fan assisted ground effect
https://grassrootsmotorsports.com/articles/plan-of...
Edited by SystemParanoia on Wednesday 21st September 10:01
Actually looking at that picture, it does make you wonder how it had any effect !
From the McLaren press release 28 May 1992
GROUND EFFECT
BY DIRECTING AIRFLOW BENEATH THE WORKINGUNDERFLOOR, AIRSTREAM IS HARNESSED TO GENERATEPOWERFUL, STABILISING DOWNFORCE
The McLaren F1 is the world’s first production car to feature full ground-effect aerodynamics with fan assistance. ▪ By careful management of airflow between the McLaren F1’s underfloor and the moving road surface beneath, powerful aerodynamic forces can be harnessed – as in Formula 1 – for the driver’s benefit. ▪ Management of this airflow regime has come to be known as a ‘ground-effect’ aerodynamic system. ▪ Airflow beneath the car is compressed against the underlying roadway and then released through an expanding-section exit channel at the car’s tail – the curving underfloor surface of which is known as the ‘diffuser’. As airflow velocity has been accelerated through this underfloor ‘venturi’ system, so the pressure within it falls, and this low pressure area may then be harnessed as ‘downforce’ to suck the moving car bodily down against the roadway. ▪ In 1978 Gordon Murray stunned the Formula 1 racing world by creating the Swedish Grand Prix-winning Brabham BT46B ‘Fan Car’ driven by Niki Lauda, which generated massive aerodynamic downforce in part by fan assistance. Formula 1 rules were quickly altered to dismiss such devices! ▪ Now, with the McLaren F1 project governed only by comparatively liberal international road-car regulations, that ‘Fan Car’ theme is to some extent being re-introduced. ▪ A complex three-part rear diffuser beneath the F1’s tail incorporates a central single surface and two reflex shapes each side generate sufficient downforce to overcome the car’s natural aerodynamic lift. ▪ Simultaneously, two powerful electric fans remove boundary layer air from the rolled S-wave of ‘reflex’ diffuser sections, helping to control movement of the Centre of Pressure – the truly significant aerodynamic factor affecting vehicle stability and handling.
From the McLaren press release 28 May 1992
GROUND EFFECT
BY DIRECTING AIRFLOW BENEATH THE WORKINGUNDERFLOOR, AIRSTREAM IS HARNESSED TO GENERATEPOWERFUL, STABILISING DOWNFORCE
The McLaren F1 is the world’s first production car to feature full ground-effect aerodynamics with fan assistance. ▪ By careful management of airflow between the McLaren F1’s underfloor and the moving road surface beneath, powerful aerodynamic forces can be harnessed – as in Formula 1 – for the driver’s benefit. ▪ Management of this airflow regime has come to be known as a ‘ground-effect’ aerodynamic system. ▪ Airflow beneath the car is compressed against the underlying roadway and then released through an expanding-section exit channel at the car’s tail – the curving underfloor surface of which is known as the ‘diffuser’. As airflow velocity has been accelerated through this underfloor ‘venturi’ system, so the pressure within it falls, and this low pressure area may then be harnessed as ‘downforce’ to suck the moving car bodily down against the roadway. ▪ In 1978 Gordon Murray stunned the Formula 1 racing world by creating the Swedish Grand Prix-winning Brabham BT46B ‘Fan Car’ driven by Niki Lauda, which generated massive aerodynamic downforce in part by fan assistance. Formula 1 rules were quickly altered to dismiss such devices! ▪ Now, with the McLaren F1 project governed only by comparatively liberal international road-car regulations, that ‘Fan Car’ theme is to some extent being re-introduced. ▪ A complex three-part rear diffuser beneath the F1’s tail incorporates a central single surface and two reflex shapes each side generate sufficient downforce to overcome the car’s natural aerodynamic lift. ▪ Simultaneously, two powerful electric fans remove boundary layer air from the rolled S-wave of ‘reflex’ diffuser sections, helping to control movement of the Centre of Pressure – the truly significant aerodynamic factor affecting vehicle stability and handling.
Edited by Gary C on Wednesday 21st September 10:08
TooMany2cvs said:
Which is great until the filter blocks up.
Can you imagine the tantrums on a track day, after ArielBoy shot-blasts everybody else's cars?
You've not got a great grasp of how filters work, have you.Can you imagine the tantrums on a track day, after ArielBoy shot-blasts everybody else's cars?
FWIIW, the IP on this project isn't Ariel's, I don't think. Their partners on the project were Totalsim (computational fluid mechanics) and Delta Motorsport. IIRC it was the latter who came up with the clever stuff.
Equus said:
TooMany2cvs said:
Which is great until the filter blocks up.
Can you imagine the tantrums on a track day, after ArielBoy shot-blasts everybody else's cars?
You've not got a great grasp of how filters work, have you.Can you imagine the tantrums on a track day, after ArielBoy shot-blasts everybody else's cars?
With a filter, unpredictable loss of suction.
Without a filter, shot-blasting.
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