I translated the text of the book (in italic my comments):
Enrico Benzing wrote:
At the end, to the family of high-lift devices also belongs the most simple systems for boundary layer control, on the suction side of the wing. About that, courtesy of ing. Giampaolo Dallara, the author could perform a rapid experimentation, meant as general evaluation, with the application of NACA parameters related to the flow. Starting from the coefficient of volume of the flow Cq, defined as the ratio :
Cq = Q / (V0 Sa)
between the flow thru the slot Q [m3/s] and the product of freestream velocity V0 and wing surface Sa.
The test was made on the old Dallara windtunnel, 1:4 scale, with a wing of dimensions at the limit of aerodynamic blockage, in the small test chamber, so results with too high angle of attack or with presence of vibrations weren’t accepted. The model of the wing was made in wood (with aluminium endplates) based on the airfoil Be 183-167 [max thickness 18% at 30% chord, max camber 16% at 70% chord], chord C = 150 mm and span L = 500 mm (a.r. = 3.33) following dimension of the F1 wings at the time, in 1:2 scale.
As shown in figure 3.37 on the suction side of the wing, at 45% chord, it was created a slot for suction of the boundary layer, connected with an appropriate dimension internal chamber. The model has been tested also with a flap, made with airfoil Be 152-155, chord c = 45 mm. For simplicity the flap was mounted directly on the trailing edge of the main element obtaining an average geometry of the slot [it means in a Junkers assembly, ie, without modification of the main element trailing edge to create an optimal shape of the slot]. Compared with the whole assembly, total chord C = 166 mm, the flap is 27% C. Obviously the results have to be restricted to this kind of test, with the characteristics of the model and the Reynolds adopted. In fact, after the same airfoil Be 183-167 was tested in the Orbassano’s Fiat windtunnel, for the wing of the Lancia Endurance Gr.6, in 1:1 scale, any evaluation has to be made in relation to the indicated parameters. Hence, if the real size wing (a.r. 3.35) gave –Cp = 2.05 already with i = -12° [Cp is Cl], with Re = 890000, it has to be noticed that the –Cp = 2.07 at i =-24° of the smaller model (with minimal imperfections) was reached with the smaller Reynolds (Re = 230000) of the old Dallara windtunnel. With that in mind it’s possible to appreciate, in fig 3.38, the –Cp and Cr [Cr is Cd] curves, as regression of data from valid tests, of the wing in 1:2 scale, configuration as seen in fig. 3.37 and simple sealing of the slot for suction of the boundary layer (it would have to be optimised for each airfoil and each configuration). The most significant result is that of practical invariability of drag, even at the AoA corresponding to maximum downforce. And that in perfect armony (see fig 3.39) with the same configuration where at the main element was added the flap.
And the text on the website
http://www.benzing.it/enrico.ali.htm (although he really says nothing particularly useful) :
The innovation, for this Formula 1 wing, in 1:2 scale, is hidden inside the main section, and is a device for boundary-layer control, able to considerably increase downforce coefficient Cz. The realization of the model, wood, with airfoils Be 183-167 and Be 152-155, was very difficult for accuracy requirements, and was founded by Peugeot. The test was made in the old Dallara windtunnel in Varano de’ Melegari, Parma.
kilcoo316 wrote:
Reca, did it just have a hole for the camera or was there an applied negative pressure from outside to inside?
No mention of a device applying negative pressure in the text.
Ciro :
I know you were half serious in your remarks about forgetting the idea, I was too in my answer but apparently not good enough to make it noticeable, sorry. Maybe it’s because I tend to be a bit peaky when people suggest that aero is what ruins f1 and should be eliminated... as someone said once, “you can’t expect turkey to vote for Christmas”...
Anyway, I’m convinced that a better use of the “memory eraser” would be to persuade everybody in the world that you are Bernie Ecclestone. I think it would give a satisfying life
