Flow diverting wind tunnel

1. A wind tunnel device comprising:

a tunnel configured to receive forced air and having a supply inlet an exhaust outlet and a generally rectangular path;

a plurality of rotatable turning vanes positioned in a corner of the generally rectangular path of the tunnel between the supply inlet and the exhaust outlet, wherein at least one rotatable turning vane comprises a recess configured to accommodate an adjacent closed rotatable turning vane of the plurality of rotatable turning vanes,

wherein:

in a first configuration, the plurality of rotatable turning vanes are configured to permit re-circulation of air through the tunnel, and

in a second configuration, the plurality of rotatable turning vanes are configured to inhibit re-circulation of air through the tunnel.

2. The device of claim 1 , wherein the at least one rotatable turning vane is configured to overlap a portion of the adjacent closed rotatable turning vane along the recess.

3. The device of claim 1 , wherein the at least one rotatable turning vane is configured to form a substantially air-tight seal with the adjacent closed rotatable turning vane.

4. The device of claim 1 , wherein the at least one rotatable turning vane defines a curved contour on a first side, the curved contour configured to direct air around the corner of the tunnel.

5. The device of claim 4 , wherein the recess of the rotatable turning vane is on a second side of the rotatable turning vane opposite the first side.

6. The device of claim 1 , wherein the plurality of rotatable turning vanes are spaced intermittently along a diagonal line from a first end of the corner to a second end of the corner.

7. The device of claim 6 , wherein the plurality of rotatable turning vanes are configured to simultaneously rotate.

8. The device of claim 1 , wherein the recess is configured to prevent interference between the at least one rotatable turning vane and an end plate of the adjacent closed rotatable turning vane.

9. The device of claim 1 , wherein the at least one rotatable turning vane comprises an end plate and the recess is formed in the end plate.

10. The device of claim 1 , wherein:

the supply inlet is coupleable with a supply duct having a first damper, and

the exhaust outlet is coupleable with an exhaust duct having a second damper.

11. The device of claim 10 , wherein the plurality of rotatable turning vanes are movable into:

the first configuration when the first and second dampers are biased toward a closed position, and

the second configuration when the first and second dampers are biased toward an open position.

12. A method of operating a wind tunnel comprising:

configuring the wind tunnel as an open-return wind tunnel in which the wind tunnel defines a generally rectangular path and is configured to permit air to enter the wind tunnel via a supply inlet and exit the wind tunnel via an exhaust outlet, wherein the wind tunnel comprises a plurality of rotatable turning vanes positioned in a corner of the generally rectangular path of the tunnel between the supply inlet and the exhaust outlet, and wherein at least one rotatable turning vane comprises a recess configured to accommodate an adjacent closed rotatable turning vane of the plurality of rotatable turning vanes; and

rotating the plurality of rotatable turning vanes between:

a first configuration, in which the plurality of rotatable turning vanes are configured to permit re-circulation of air through the tunnel; and

a second configuration, in which the plurality of rotatable turning vanes are configured to inhibit re-circulation of air through the tunnel.

13. The method of claim 12 , wherein in the second configuration, the at least one rotatable turning vane overlaps a portion of the adjacent closed rotatable turning vane along the recess.

14. The method of claim 12 , further comprising establishing a substantially air-tight seal between the at least one rotatable turning vane and the adjacent closed rotatable turning vane.

15. The method of claim 12 , wherein the rotation of the plurality of rotatable turning vanes comprises simultaneously rotating the plurality of rotatable turning vanes between the first and second configurations.

16. The method of claim 12 , further comprising operating the wind tunnel, with the plurality of rotatable turning vanes in the first configuration, as a closed-loop wind tunnel in which air is recirculated through the wind tunnel via a fan positioned in the wind tunnel.

17. The method of claim 12 , further comprising using an electric actuator to transition the plurality of rotatable turning vanes between the first configuration and the second configuration in response to a signal from a computer controller.

18. The method of claim 12 , further comprising directing airflow away from right angle surfaces of the wind tunnel using a curved contour of the at least one rotatable turning vane.