How to create exhaust flow in the wind tunnel

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mep
29
Joined: 11 Oct 2003, 15:48
Location: Germany

Re: How to create exhaust flow in the wind tunnel

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Of course not.
You wont get close to the results you need when you use a fluid instead of a gas.
Just for example the density of water is around 832 times higher than the one of air. Then is air compressible and water not. Also has water a high surface tension. There are a lot of reasons why water can't replace air for such tests.

marcush.
marcush.
159
Joined: 09 Mar 2004, 16:55

Re: How to create exhaust flow in the wind tunnel

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the pulses are quick ,aren´t they? I´d think a good flow of air would be ok and as we have seen the air will cool rather quickly downstream ...
But speaking of waste heat ...the radiators and engine and exhaust pipe heating the air of the inner flow will have a serious influence and to not test under realistic conditions would surely add a cloud of uncertainty to your tunnel results?so isn´t it already a fact of life that windtunnel models need to dissipate waste heat replicating the real world situation and the tunnel must cool down the returning air back to ambient conditions -say your aero test is replicating Hungaroring conditions...Brings up the question if the belt and bottom are heatable as well or are hot by design...Change of track temps usually have surprising effects on aero performance..the legendary cloud in the roight moment of Indy 500 qualy giving a extra few pounds of downforce..

marcush.
marcush.
159
Joined: 09 Mar 2004, 16:55

Re: How to create exhaust flow in the wind tunnel

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Sauber tunnel still considered state of the art...
http://www.autosport.com/news/report.php/id/94274

with a facility ot that quality -why does Gascoyne or Ferari or TR not collaborate or try to forge a deal with Sauber...If I know correctly there was never a three shift workload there and it should be well possible to establish a second preparation area and sequenced workloads to use this tunnel to itas full potential.

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mep
29
Joined: 11 Oct 2003, 15:48
Location: Germany

Re: How to create exhaust flow in the wind tunnel

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Obviously having the best wind tunnel doesn't mean you are running at the front and this is not just true for Sauber but also for Toyota.
When Sauber even gets the good Ferrari engine and gearbox and has the best tunnel so why are they behind the Silvergurke?

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HampusA
0
Joined: 16 Feb 2011, 14:49

Re: How to create exhaust flow in the wind tunnel

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People is a much more important asset then all the money or technology in the world.

Toyota is a living proof of this.
The truth will come out...

shamikaze
shamikaze
0
Joined: 06 May 2010, 09:05

Re: How to create exhaust flow in the wind tunnel

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the heat should not be a problem if the windtunnel is open-return type and not closed-loop. Do we know which type the teams are using for their modelling ?

Given the 60% modelling requirements, I would assume your airspeed needs to be at 60% as well. Meaning 200km/hr = 120 km/hr windtunnel airspeed , 300km/hr = 180km/hr tunnel airspeed.

Open-Return tunnels are easier and cheaper to build for those airspeeds. Also, with open-return, you wouldn't need heat-exchangers so you can run a heat-sourcein the car. You would need a very good design though in order to get good an accurate data from an open-return tunnel.

Billzilla
Billzilla
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Joined: 24 May 2011, 01:28

Re: How to create exhaust flow in the wind tunnel

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mep wrote:You wont get close to the results you need when you use a fluid instead of a gas.
FWIW both water and air are fluids, though only water is a liquid.