Questions tagged [wind-tunnel]

A wind tunnel is a tool used in aerodynamic research to study the effects of air moving past solid objects. A wind tunnel consists of a tubular passage with the object under test mounted in the middle. Air is made to move past the object by a powerful fan system or other means.

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9
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3answers
10k views

How are wind tunnels used with scale models?

This answer introduced me to the problem of using scaled models in a wind tunnel. How are wind-tunnels used in practice (for modelling the performance of subsonic airplanes)? In particular: Do they ...
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Can you fly a plane in a wind tunnel?

There are very large wind tunnels out there. Wouldn't it be very efficient to test new airplanes flying them "on the spot" inside of these tunnels? That is, in free flight - not mounted to a pylon? ...
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1answer
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What are some specific benefits of cryogenic wind tunnels?

What are some benefits to using a cryogenic wind tunnel over a more traditional one? Are there certain aerodynamic properties or principles that are better studied at low temperatures?
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2answers
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How is windspeed scaled in wind-tunnel tests?

Let's say you have a scale model that is 1:10th the size of the real thing. You want to test this in a wind-tunnel. Do you also scale down the windspeed 10x? Why or why not? I would think it has to ...
5
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4answers
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Can this design provide more lift force than thrust from engine?

The problem is depicted in the picture: Generally, why we don't use engine blow wings to fly? Can we use wind-tunnel-like wing to generate lift force? Can it generate more lift than thrust? If it ...
4
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1answer
4k views

How should the pressure coefficient distribution from a wind tunnel experiment be interpreted?

I'm doing a wind tunnel experiment and I'm trying to plot the pressure coefficient distribution for the upper and the lower surfaces of an airfoil based on experimental data. The airfoil chord is 150 ...
4
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2answers
3k views

Does the Reynolds number on a smaller model need to match the one of the original aircraft?

1.Airbus 380-800 : The overall length of it , is 72.72 m and its cruise speed is 903 km/h. Based on the mean chord of wing , its Reynolds number in cruise phase is around 75 millions. Now , a 1/18 ...
3
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2answers
202 views

How should I attach an aircraft model in a wind tunnel when testing wind gust/yaw stability?

Where should I attach the rod to the aircraft model when simulating wind gust /weather vane effect in wind tunnel testing? At the center of gravity, behind the CG, in front of the CG...?
1
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1answer
343 views

Is there an analytical description of the NACA 642-015A profile?

While searching for symmetric profiles I stumbled across different definitions (point-clouds) of the NACA 642-015A profile. http://airfoiltools.com/airfoil/seligdatfile?airfoil=n64015a-il http://www....
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1answer
122 views

Can I measure induced drag with a simple wind tunnel test?

Device can measures total drag force and lift of wing for given AoA and airflow speed. Wing both wingtips are far away from side walls. Airflow speed is constant all the time:50m/s TOTAL DRAG=...
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3answers
184 views

Wing vs wall to wall wing,total drag comparation at same AoA?

Compare total drag of wall to wall wing vs wing(open tips) in wind tunnel,AT SAME AoA. My first intuition is that wall to wall wing has higher pressure drag at outward parts of wing,because side-walls ...
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1answer
713 views

How do we derive Lift Coefficient of an airplane's wing?

In many references I read that lift coefficient ($C_l$) is a product of wind tunnel test. But many times I read the formula to calculate the coefficient of lift. From the lift equation, $$L=\frac{1}{2}...
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2answers
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How to calculate the drag on an airfoil from momentum equation (Fundamental of Aerodynamics 5th edition, J.D.Anderson)?

If you got the book, please read 2.6 section (page 135). Here is my sumary of this section: An airfoil in a wind tunnel (wingtips were butted against both sidewalls of wind tunnel). The control ...