- A tunnel with poor grammar who has beaten other tunnels in some kind of task...
- A wind tunnel is a tunnel or other enclosed structure through which artificially generated wind flows or circulates. Well, not just any enclosure. I mean, if you have two windows in your house open and a box fan in the middle to speed things up, that isn't the kind of tunnel we're talking about. Generally you can tell a wind tunnel because it looks all fancy.
- A whole bunch of blondes standing from ear-to-ear.
Wind tunnels fall into two classes, open and closed. An open wind tunnel has an intake on one side to take in air from the atmosphere, and an exhaust on the other end to outlet the air. Again, a box fan fits this definition perfectly, but doesn't count. An honest wind tunnel will have some room in the middle for a tiny model of an airplane. A closed wind tunnel makes a complete loop, allowing the same air to continue circulating. Wind tunnel technicians must take great care not to flatulate in this sort of wind tunnel, as the air just keeps going around in circles.
There are other types of wind tunnels in addition to those that circulate air.
There are supersonic wind tunnels, which circulate air really really fast. Because the air is moving faster than the speed of sound, the air in a closed supersonic tunnel can actually lap the sound that it makes. Las Vegas rakes in dozens of dollars a year in legal wagering on how fast different university and industry wind tunnels operate.
Other wind tunnels circulate smoke, so that researchers can visualise the air flow. Generally a smoke-circulating tunnel is installed with the intake above the smoking section of a restaurant, and the outlet directly above your table.
Other wind tunnels circulate water, and are used to design submarines and torpedoes. But everyone knows it's cheating for a wind tunnel to circulate water. Closed, supersonic, water-filled wind tunnels leak significant amounts of energy as gravity waves.
Wind tunnels have historically been used to design flying systems.
It is widely believed that pterosaurs were the first to use wind tunnels, to design and improve their wings. Pterosaurs were able to successfully use wind tunnels and develop flight. Tragically, they only had knowledge of closed wind tunnels, and became extinct when too many pterosaur scientists broke wind during research.
Today, wind tunnels are widely used in all sorts of manly engineering projects, just like cyclotrons, nuclear reactors, and other satisfyingly enormous devices.
Perhaps the most famous of all American wind tunnels is Rush Limbaugh, known to funnel intensely hot air with a force exceeding velocities of a category 5 hurricane; most notably this wind tunnel only blows at right angles, regardless of the orientation of the observer.