10 replies to this topic

[molive]

What is it that make wind tunnels so expensive (Ferrari´s new one cost over US$15million)?

I thought they were just oversized tubes with a huge fan in one side ...

anyone?




[This message has been edited by molive (edited 02-08-2000).]

[StuffedBeaver]

Molive,

I used to work in an aviation wind tunnel and as with much of life the simple things in reality are complex.

It's a lot more involved than having a big fan at one end of a tube.

The prime considerations are as follows:

1. Cooling - the air in the tunnel has to be kept at a constant temp, as if you imagine air whizzing around at 200mph + it gets hot quickly and leads to inconsistant results of the data. This involves having a cooling plant with pumps, water treatment and personell to run it.

2. The wind tunnels have to be pressure tested, thus all welds and joints etc. have to be manufactured to the highest degree and therefore expertise which is very expensive.

3. Scale models are expensive and have hundreds of sensors all over the body. (this is a complete new subject in itself)

4. The control room and the electronics used are quite complex, thus expensive.

5. the people who run it are mostly engineering degree educated people and thet ain't cheap.



------------------
The Beav

[Pascal]

Another element has to be taken into consideration in the case of a Formula 1 wind tunnel: the ground.

This may sound obvious, but cars (except Le Mans Mercedes) are not designed to fly in the air, and there interaction with ground surface has to be measured accurately. So nowadays, models are put on some sort of high-speed conveyor-belt simulating speeds above 300 km per hour. This setup has some influence on the airflow generated inside the tunnel, and that's why teams have been so insisten to have their own wind tunnel these last few years. They simply need a complex custom-made configuration.

[molive]

Thanx guys.

Of course I was kidding about the big fan things...but still, I´m impressed.:0

Would anybody have a basic layout of a wind tunnel just to illustrate how complex it really is?

BTW, I am architect, so I´d have no problem reading a tech scheme.

[bschue]

Wind.

[Byrellium]

I am a Union Carpenter and I have worked on a wind tunnel near Dertoit for Ford. I was really suprised at the size of the job. I had no idea it would be so huge. I never got to see the tunnel at or near completion, unfortunately, but after seeing the size of it I can understand the cost. Just the amount of concrete and all the things that are enclosed in the concrete is substantial. I can only imagine the power requirements of the fan!

[Christiaan]

Pity I stopped working, because now I do not have access to a scanner.

Molive, my university has two tunnels. One with the capabilities of a 20cm object and the other about 1m length and 30cm width. The interesting thing is that the 1st tunnel is over 10m long, and is just a straight tube. The second one is like a big tube formed into a squarish path. Its about 15m long and 6m high.

The University of Stellenbosh has one constructed with the same principles, and its workspace is about 2x4m. The total construction is about one and half stories high.

The reason for the size is that the air has to be very very carefully conditioned in terms of temperature, density, and most importantly streamlining and velocity profile. This can have adverse effects on your results, if not properly done.

At every corner in the square are adhustable vanes. Somewhere else in the path are devices for controlling humdity and temperature.

I saw a picture of the VW wind tunnel which I believe is the worlds largest. It didn't have the same square setup, so I wonder how that one worked.

[Mellon]

http://www.atlasf1.c...jan26/gray.html

[molive]

Mellon,

Thanks for the link.

I confess I'm a bit bored with endless tech explanations, that's why I almost never check the "Taking the Lid Off F1" series.
The pictures in the article are very good.
I'd love to see some plans and sections tough.

Anyway,

I'm a bit upset because I tried to find the thread and only after trying several levels in the reader's comments I realized someone had moved it here. At least he(she) should have warned me(us).

whatever.

[Martin]

Looking at the pics in the article mentioned above, I noticed that the car's wheels appear not to be turning - surely they must be tested with the wheels going at the rolling road speed?
As an additional thought - I presume angled wheel spokes are banned aren't they? otherwise you could deny moving aerodaynamic device charges by say they were wheel design and effectively have massive pumps sucking air from underneath. You'd of course have to remeber to put the lefthand wheels on the left side... to avoid producing a ver fast hovercraft.

[Ray Bell]

Another reason for sizes seemingly larger than you would think would be the tendency for the wind to get hung up on the walls. I think this is called 'laminar flow.' You'd need your subject to be well clear of this influence.