On the final day of testing at the Bahrain International Circuit, Ferrari's Felipe Massa was the fastest man on track. The Brazilian was faster than BMW Sauber's Nick Heidfeld and Toyota's Timo Glock.
Neither did I, but I can definetely say yes))ISLAMATRON wrote:I havent done much wind tunnel testing... is that what they use the smoke for?
They do have 2 small extensions to the diffuser on either side of the rear wing end-plates.mariof1 wrote:From the video (4:30 or so) it's possible to see that the RB5 features a narrower diffuser (750mm) limited by the rear wing endplates rather than making use of the whole allowed width (1000mm).
Or maybe it's because the cars race in the real world not in a wind tunnel, and they want to verify the way the aerodynamics work in that turbulent and windy environment?El Presidente wrote:My guess is that its PSP - Pressure Sensitive Paint, used to validate existing windtunnel and CFD work. Why do it outside rather than in the tunnel? Well do you want the tunnel to be out of action after every test while its getting cleaned?
Yes the smoke is used to determine the stream lines of fluid particles.ISLAMATRON wrote:I havent done much wind tunnel testing... is that what they use the smoke for?timbo wrote:Apparently they can monitor such changes using onboard camers - notice additional one at the rear of sidepod.Scotracer wrote:The Reynolds number will constantly changing on these surfaces so the seperation points will be changing all the time.
Colour me sceptical.
I actually like that idea of using paint, but I think the downside is that they can only see what happens on surfaces, but not how vortices interact in volume.
Are you saying that there isnt an aweful lot of green stuff on the suspension arms? It looks as if that was the origin of the paint to begin with...wesley123 wrote:That isnt for monitoring airflow.
The green stuff flows up after the upper arms so that cant be it as the suspension arms arent allowed to produce downforce.
Sure, though velocty of crosswinds etc are in general going to be small and variable compared to that of car. Another posibility could be they wanted to see flow while following another car, obviously difficult in a tunnel that is capacity restricted.myurr wrote:Or maybe it's because the cars race in the real world not in a wind tunnel, and they want to verify the way the aerodynamics work in that turbulent and windy environment?El Presidente wrote:My guess is that its PSP - Pressure Sensitive Paint, used to validate existing windtunnel and CFD work. Why do it outside rather than in the tunnel? Well do you want the tunnel to be out of action after every test while its getting cleaned?
But then again, how difficuly could it be to place two 2/1 scaled cars behind eachother in a tunnel ?El Presidente wrote:Sure, though velocty of crosswinds etc are in general going to be small and variable compared to that of car. Another posibility could be they wanted to see flow while following another car, obviously difficult in a tunnel that is capacity restricted.myurr wrote:Or maybe it's because the cars race in the real world not in a wind tunnel, and they want to verify the way the aerodynamics work in that turbulent and windy environment?El Presidente wrote:My guess is that its PSP - Pressure Sensitive Paint, used to validate existing windtunnel and CFD work. Why do it outside rather than in the tunnel? Well do you want the tunnel to be out of action after every test while its getting cleaned?
Not difficult, just less accurate because of the scaling effect, thats the reason for the huge investment in moving floor full scale tunnels.Moanlower wrote:But then again, how difficuly could it be to place two 2/1 scaled cars behind eachother in a tunnel ?
For small yaw angles could can fairly accurately use wind tunnels (despite having to use a stationary road) but yes, for large yaw angles you cannot accurately simulated and in most wind-tunnels you will start to get wall effects as the tunnels aren't wide enough to accommodate a car sitting laterally.Giblet wrote:Everyone here, for all their expertise, seems to be forgetting that in a rolling road wind tunnel, the car is always facing into the wind. Wind tunnels are not good for figuring out if crosswinds and different angles of attack are effecting the vehicle.
That being said, the different angles are likely all tested through CFD, but since they can't be easily verified with the wind tunnel, going back to basics is the only way to see if what you figure is right.
This is why I test my level on a known level surface or plumb wall to make sure it is accurate.
Instrumentation can be off, and needs to verified from time to time.
Other then that, I figure that the gigaflops are being used right now at the Mclaren tech center, and a lower tech solution can sometimes still be the best.
I can think of at least 1 full-scale rolling road wind tunnel for which this is not true.Everyone here, for all their expertise, seems to be forgetting that in a rolling road wind tunnel, the car is always facing into the wind.
, very cool. 
