When one swings a short corrugated pipe segment around one's head, it produces a
musically interesting whistling sound. As a musical toy it is called a “Hummer” and as a
musical instrument, the “Voice of the Dragon.” The fluid dynamics aspects of the instrument
are addressed, corresponding to the sound generation mechanism. Velocity profile
measurements reveal that the turbulent velocity profile developed in a corrugated pipe
differs notably from the one of a smooth pipe. This velocity profile appears to have a crucial …