pictures of the wind tunnel
Entrance cone of the wind tunnel:
Even the belt was not enough to curve the four parts in the right position!
The curve is simply parabolic function.
The entrance cone is kind of too short, but I needed place…
Inner side surface is not perfect.
Build up with some improvisations.
The “honeycomb” (balsa) was a bit complicated to make and is still a problem, slowing down the airflow but much better for steadiness (believe or not!).
The anemometer used as reference for speed measurement:
Speed is only around 53 km/h in the test room, limited by the low pitch of the wind tunnel propeller(s) and the poor performance of the motor that spinning it.
The entrance cone should be easy to remove and replace.
The door of the test room:
This is just to prevent the door from falling when speed comes back to zero:
Pitot tube installed for “velocity distribution” tests:
Exit cone from the inside:
Wind tunnel motor speed control:
2800 tr/min, rated 900 W dead lawn mower motor and 2 graupner 20x12 props (needs 4 blades 20x20 and a good motor).