A wind tunnel is a research facility used to study the effects of air flow around objects. It consists of a long, enclosed tube with powerful fans that generate air flow at controlled speeds. Models of objects, such as airplanes or automobiles, are placed inside the wind tunnel and air flow is directed over them to simulate real-world conditions. Researchers can then study the aerodynamics of the object and make measurements to optimize its design and performance. Wind tunnels are commonly used in aeronautics, automotive engineering, and sports equipment development.