Awhile back, I mentioned that bike manufacturer Specialized had built their own wind tunnel to test cycling equipment. In this video, they provide a walk-through of their facility. Although there are features unique to this tunnel and its intended purpose, much of what Chris and Mark describe is standard for any subsonic wind tunnel. The story begins upstream in the inlet and contraction, where air is pulled into the tunnel. Honeycomb flow straighteners direct the incoming air, followed by a series of mesh screens. These screens break up any turbulent eddies, which helps smooth and laminarize the flow. The test section is where measurements occur, whether on cyclists or other models. This part of the tunnel is usually equipped with many sensors and specialized equipment, like the balance shown. These allow researchers to measure quantities like force, velocity, pressure, and/or temperature. Then the wind tunnel widens gradually in a diffuser, which slows down the air and helps prevent disturbances from propagating upstream. Finally, the fans at the back provide the source of low-pressure that drives the air flow. (Video credit: Specialized Bicycles; submitted by J. Salazar)
Specialized’s Win Tunnel
