The aerodynamic coefficient improves with matt black
by Paolo Ciccarone
Combine business with pleasure. For Mercedes, profit is the social message against racism and coloring the Hamilton and Bottas car black. A courageous and important choice with a strong symbol, color, that from silver arrows has transformed the black arrows of Styria into this world championship start. As often happens, But, to a choice of marketing and communication, a technical choice follows. Or, decided to color the car in a certain way, what advantage we can get? And here comes the genius of Mercedes and its technicians, because the black used to paint the cars also has a different purpose. It's called aerodynamics and we explain why. For some time we have been talking about the temperature problems of German and black cars, at first sight, would only make things worse. Except that the special treatment creates a higher temperature on the surface layer than, in the moment of action, or air penetration, what looks like a disadvantage is actually an advantage. The air is a fluid and in contact with the surfaces of the car creates micro vortices. These vortices are all the denser the denser the air. Therefore, to decrease fluid threads and decrease micro vortices, it would be necessary to heat the air to make it less dense. And here comes the fun part with the paint treatment. In Italy Nanoprom has continued the development of these micro particles for years by developing the nanotechnology of paints, which besides being light have two functions: heat dispersion and therefore to protect the various accessories on the cars, and an irradiation such as to make the outer layer a phenomenal conductor. Starting from this principle, Mercedes has also embraced the line of special colors, but choosing the polish (which is easier to clean than opaque) , while opaque was introduced on Red Bull which has always used films and opaque transparent, easier to clean and remove, while Ferrari last year chose to paint its car in matt, with problems related to cleanliness on this choice. An opaque color reflects less and absorbs more heat, reduces the presence of impurities collected on the track, but it is a color that better dissipates heat while absorbing more of it and with this increases aerodynamic penetration. We enclose a report by engineer Jean Claude Migeot with the results obtained in the wind tunnel on studies with Nanoprom paints:
Please find attached the Nanoprom test results,
With seven tests on three different set-ups, we
found a reduction in Cx ranging from 0.2 to 0.5%. This
corresponds to an average reduction in Cx amounting to
approximately 0.8%. The measurements are reasonably
repeatable and all constitute improvements, so it can be said that
there is an effect and it is measurable. Among other things, it
is more or less quantifiable as due to a reduction in the friction
coefficient amounting to around 10%, which is similar to results
obtained for flat bases and on pipes with tests which Nanoprom
has had carried out by a university (Trieste, I think) and another institution.
Jean Claude Migeot
Practically, using the type of special paints and the opaque coloring, there is an improvement in the Cx which reaches the 0,8 percent, or almost a point and the reduction of friction leads to a minus 10 percent. That's why after Red Bull and Ferrari, even the Mercedes has converted to the different color and moreover with a black that accumulates heat, but it makes the air more fluid, therefore reducing friction and micro vortices on the bodywork improving aerodynamic penetration. Someone says they have improved on 1 point of Cx, that at those speeds is really a lot. When it is said to combine business with pleasure ...
[ Source: gazzettadiparma.it ]
