Firstly, thank you to everyone who has taken the time to contribute to the other thread I original contributed to, in response, I will take a glass of something red and french and settle in a corner for a while and pass the occasional comment or express a view. If anyone is interested, I much prefer a Cote du Rhone or Chateauneuf du Pape.
I’ve been reading and thinking about the RB diffuser solution again, just trying to understand how they have developed so much performance from it. Here is a view, not necessarily right but considered.
With a conventional aircraft wing the airflow is parted by the leading edge and air travelling over the top has to flow faster than the air underneath thus creating a pressure differential which causes the lift. As we all know the wings on racing cars are turned over, so the faster airflow and therefore the lower air pressure is on the underside of the wing, hence the wing creates downforce. What is critical to all of this is ensuring that the air streams join back together cleanly otherwise you are just creating turbulence and therefore drag.
This lift/downforce effect can also be achieved to a lesser extent by creating a temperature differential between upper and lower sides of the wing(s). The RB 2010 car changed mid season, there were subtle changes to the way exhaust was ported but as important was what was happenning with the radiator and oil cooler air. It seems that some of this ‘waste’ is blown out to an area under the main plane of the rear wing, thus reducing the pressure ever so slightly. It is important to note that this airflow does not seem to interfere with airflow over the lower wing section. Couple this with the hot blown diffuser where the exhaust gas is blown underside of the diffuser even when off-throttle you have a marked performance advantage.
What I think I’m saying is that Adrian Newey has found a solution that uses multiple solutions which work individually but don’t intefere with one another.