10 replies to this topic

[T54]

The (rare) pictures of the 1937 streamlined V12 Delage built for the Grand Prix de l'Automobile Club de France to the new regulations show a possible "reverse-wing" thinking on the part of aerodynamicist Jean Andreau. Not sure if this was ever discussed here, but what do you think?
The car was crashed in testing, repaired and later shown on the Labourdette stand at the 1937 Paris auto show and the body later discarded. Apparently the chassis, rebodied, still exists in England according to what I read.

I think that the car is too cool to ignore, and is a real beauty, much more elegant than the Peugeot 802 by the same designer. What do you gentlemen think of this possible early ground-effect theory?

 

 

Edited by T54, 03 September 2013 - 00:03.

[T54]

I was thinking "reverse-wing", the first step in ground effect. There is ample room under the chassis, while of course effectiveness would be minimal and the car may encounter the same lift issues that were present in the Chaparral 1 and Chaparral 2 designs using the reverse-wing theory.

My question is, when seen from the rear, the car appears to have been designed with "extraction tunnels". If Jean Andreau who was no one's fool and a specialist in aerodynamic separation after designing ordnance for the French armed forces shortly after WW1, actually THOUGHT of using the car as a reverse wing, that would have been an interesting step to ground effect.

[D-Type]

Rather than cosciously designing the car as a 'reverse wing' was Jean Andreau simply trying to smooth the airflow under the car?  At the time many car makers streamlined the body of the car and ignored the underside.

I vaguely recall a 1950's [boys'] book about cars specifically saying that a contribution to the excellent aerodynamics of the Porsche 356 was that the manufacturers also steamlined the underside.

[fnqvmuch]

I don't know about an 802 Andreau but the N4X on the 402 was not a one-off ( and a few survive, i think ) 

and it was worked through a few refinements - at one stage can even be seen to try not just drop shapes around front wheels -  more flat, 

almost concave sides.

(attached for this present debate are some shots of uncertain provenance and which therefore will be deleted within the day...)

steven

Edited by fnqvmuch, 04 September 2013 - 04:04.

[Bloggsworth]

The giveaway for it being smoothing rather than ground-effects is the distance between the ground and the car.

[RDV]

...but even earlier Rene Prevost had already shown ground effects...in 1928 in fact=

 

[/URL] Uploaded with ImageShack.us

 

 

....how the @£$%@& does one load images in posts in the new format?

[Vitesse2]

Surely if Andreau had been interested in working with ground effect the obvious thing to try it on would be Thunderbolt, the LSR car he designed for George Eyston? It has his signature tail fin, but I don't think there's any evidence of a Venturi underneath - unlike the Auto Union in which Rosemeyer was killed and which probably was an ill-thought-out attempt to use ground effect.

[T54]

Well this is why I solicited knowledge of the knowledgeable historians here. You see, Prevost and Andreau knew of each other, and indeed Prevost had some ideas about creating traction by pushing the car down using negative lift. So it is not inconceivable that Jean Andreau who was far from being an aero ignorant, may have tried to create a venturi effect (even if minor) using a reverse wing profile in both the Delage and the Peugeot, and I was wondering if anyone here would know historical details from older documents.
As far as the Thuderbolt, it being a straightline car, few would have understood the need to push the car down that signified drag, except for Ferdinand Porsche and Fritz von Opel...

But both Andreau cars reflect this venturi-effect design at their back, so there could have been some thinking about it.

In any case, while six Peugeot 802 with Andreau body were commissioned by Peugeot and built, and some were actually sold and have survived in the Peugeot collection and in private hands, the Delage body was likely dismantled and trashed.

The Peugeot streamliner was supposed to be a "802" and not a 402, and was to receive the V8 designed in Sochaux but the war stopped that idea.

Edited by T54, 03 September 2013 - 15:33.

[T54]

I found this that gives a bit more details about the background of Jean Andreau:

 

http://translate.goo...iw=1280&bih=646

 

It's from "Google translate" so be kind to the poor English!

Edited by T54, 03 September 2013 - 00:00.

[Catalina Park]

If he was aiming to reduce lift I think he probably failed miserably. The front wings are really wings.
Looking at the body all I see is lift from all the curved upper surfaces.

[Vitesse2]

It seems Andreau may have been partly responsible for those hideous bloody wind turbines! Although there does seem to be some cross-pollination between this and ground effect. This is from Flight, February 13th 1953:

 

 

AN  80-FT.  D.H.  AIRSCREW !

A M O S T  unconventional  de  Havilland  airscrew  is  shortly  to  go
into  service  with  B.E.A.;  of  variable-pitch,  two-bladed  type
and  fully  feathering,  it  is  of  80ft  diameter.  In  case  this  news
appears  of  doubtful  authenticity,  it  may  be  added  that  B.E.A.  in
this  context  stands  for  British  Electricity  Authority,  and  that  the
80ft  airscrew  is,  in  fact,  an  experimental  power-generating  wind-
mill, to  be  tested  this summer on a site near St. Albans.  Operating
on  the  "depression"  principle  originally  developed  by  Andreau  in
France,  the  rotor  has  hollow,  open-tipped  blades  from  which  the
internal  air is  extracted  by  centrifugal  force  as  they  revolve.  This
creates  suction  in  the  hollow  shaft  and  also  in  the  100ft  tower
which  carries  it;  and  in  this  tower  is  the  axial-flow  air  turbine
that  drives  the  100 kW  generator.
Of  particular  interest  are  the  names  of  the  firms  principally
concerned  in the  experiment.  The  design was by the de  Havilland
Propellers, Ltd., and the machine was largely constructed  by  them,
while  the  electrical  equipment  is  by  English  Electric,  Ltd.,  and
Enfield  cables  are  used  throughout  the  installation.

Source: http://www.flightglo...?search=andreau