I gotta add to this, that people think scale is the biggest problem. So far from it. Probably 95+% of the "full scale wind tunnels" can be called full scale, but hardly called wind tunnels. Most are stationary floor with a rotating platform for yaw. Usually used for crosswind buffeting noise work or aero-thermal. I just have to add that in because it always gets me when people hail "full scale" testing meanwhile people go to these tunnels that should only be used for NVH, spend two days there and think they have done the ultimate aero testing.Tommy Cookers wrote:j a f suggests that F1 problems would be solved by using full scale and speed WTs ?bill shoe wrote:CFD and Wind Tunnels are both simulations of the actual car's running aero performance at a grand prix weekend. ....... If you can't relate either type of simulation to actual running car data then there's no point in the simulations. At that point you have the dreaded correlation crisis.
I think anti-CFD people (a.k.a. pro-Wind Tunnel people?) are setting up a bit of a straw-man argument. The assumption is that wind tunnels give the actual and correct value which can be compared to CFD to check the accuracy of CFD. If it was this simple there would never be the one or two teams per year that have a correlation crisis. ......
I guessed their (rather large) scale and speed is believed to be essentially as good as fullsize
(and without killer issues of fullsize fullspeed moving groundplanes)
though WT flow quality is always a likely suspect
some aviation WTs correlate much better than others
eg the early F-A 18 E/F carrier approach issues (though the makers stoutly claimed WT tests couldn't have predicted it)
a cynic might say that Europe has been more willing to fund the making of WTs than the making of planes (and vice-versa the USA)
the need for Re and other sweeps means that aviation WT work generally uses far less than the nominal maximum power
btw, in fun ...
the public domain now reveals that the 8'x8' supersonic Bedford UK tunnel (scrapped after 46 years use) was stated to be 60 MW
and the USA was trying to get for civil aviation 2 big new WTs in the Clinton era (iirc including cryogenic-cooled capability ?)
EDIT - Note to self
as mentioned by riff raff ? in post later, the NASA Ames 'Full Size' tunnels are more powerful
and seemingly used for testing actual aircraft and rotorcraft at full size
rotorcraft at model size cannot reconcile aerodyamic and aeroelastic factors
Wasn't that because cosworth sent them some data which was not accurate?Just_a_fan wrote:They didn't even get the fuel tank the correct size so the rest of it...
I'm no expert, however I'm inclined to think the rules hampered there ability rather than the capability of the software / hardware available at the time? They had maxed there systems out as much as the rules allowed.bill shoe wrote:Aerospace has been perfecting wind tunnels for 115 years, from the Wright brothers until today. I think it's pretty obvious that 115 years from now CFD will be superior to wind tunnels in terms of both 1. absolute performance capability and 2. cost. Really the only question is when this transition will occur, maybe 2 years or more like 20? Anyone think longer than 20 years, perhaps a rational pessimist would say 30 years? So wind tunnels are today's equivalent to buggy whips in 1880 or later.
If Manor/Virgin racing had gone out in the year 1880 and had tried to use a then-current petrol engine in a race against a horse they would have looked very stupid. But within 30 years horses had no chance. Manor got the "when" wrong, but they did not get the "what" wrong. In the broad historical arc, I don't even think they were very far off with the "when".
I am pretty sure there is already a working facility in America? I have read an article about one in Racecar engineeringJust_a_fan wrote:There is an alternative to a wind tunnel - that is a test tunnel. There is a proposal to turn a disused rail tunnel in the UK in to a very long testing facility. Basically you could send a full size car down the tunnel and it would behave as it would on the road. No need for a rolling road because it rolls on the road. It wouldn't be exactly the same as the car on a wide flat open track, of course, but the lessons learnt from wind tunnels should allow close correlation to be achieved. Certainly closer than a wind tunnel or current CFD.
Admittedly, it's just another tool in the box for the aerodynamicist to use, but it might make for an interesting alternative.
