Wind Tunnel TurboMachine.com home
I constructed this simple wind tunnel from materials from Home Depot and a motor and fan from Grainger. Material cost are approximately $200.
This wind tunnel is based on the Baals design: http://www.fi.edu/flights/first/makebigger/index.html
Click on thumbnails pictures below to see larger construction pictures.
For questions email email@example.com
This wind tunnel takes ~40 hours to build.
I use this wind tunnel for science demonstration for kids.
Here is the list of supplies:
Lexan sheet was thickness ~ .235 inch 2x4 sheet
¾ inch plywood base and frame
¼ inch panel type board
12 gauge wiring
Aluminum honeycomb for
Local composites fabricator
Auto Body Shop:
Grainger Supply motor and fan
I needed to trim the fan to fit.
1 Direct Drive Blower Motor, HP 1/4, Voltage 115, RPM 1625, Full Load Amp 2.5, Number of Speeds 3, Enclosure Open Air Over, Motor Type PSC, Mounting Ring/Stud/Hole DAYTON
1 Aluminum Fan Blade, Diameter 18 Inches, Motor Power Rating 1/12 HP, Bore Size 1/2 Inch, CW, 1140 RPM DAYTON
2C361 Today $23.26
1 Motor Run Capacitor, MFD Rating 10, Voltage 370, 60/50 Hz, Oval, Height 2 7/8 In, Width 2 3/16 In, Depth 1 5/16 In, EIA UL Base A, 1/4 In Male Terminals
Hope this helps.
The lift of a wing is equal to the change in momentum of the air it is diverting down. Momentum is the product of mass and velocity (mv). The most common form of Newton’s second law is F= ma, or force equal mass times acceleration. The law in this form gives the force necessary to accelerate an object of a certain mass. An alternate form of Newton’s second law can be written: The lift of a wing is proportional to the amount of air diverted down times the vertical velocity of that air.
This picture illustrates the effect of the air being diverted down from a wing. A huge hole is punched through the fog by the downwash from the airplane that has just flown over it.
So how does a thin wing divert so much air? When the air is bent around the top of the wing, it pulls on the air above it accelerating that air downwards. This pulling action causes the pressure to be reduced above the wing. Also, depending on the angle of the wing, air from the bottom of wing is deflected downwards. It is the acceleration of the air in the downward direction that gives lift or in other simple words "lift is produced by forcing air downwards". The forcing action is caused by net result of both the upper and lower surfaces of the wing. Newton's third law states that for every action there is an equal and opposite reaction. Forcing air downwards causes the wing to be forced upwards to support the weight of the aircraft. A wing is an efficient shape that bends the air and forces it downwards.
I would like to introduce a mental image of a wing. One is used to thinking of a wing as a thin blade that slices though the air and develops lift somewhat by magic. The new image that we would like you to adopt is that of the wing as a scoop diverting a certain amount of air from the horizontal to roughly the angle of attack. For wings of typical airplanes it is a good approximation to say that the area of the scoop is proportional to the area of the wing. The shape of the scoop is approximately elliptical for all wings, as shown in the figure. Since the lift of the wing is proportional to the amount of air diverted, the lift of is also proportional to the wing’s area.