Time domain simulation and jet behavior in the flute.
John W. Coltman · The Journal of the Acoustical Society of America · 1992
A time domain simulation using parameters closely imitating a Boehm flute gave mode oscillation frequencies varying properly with blowing velocity, terminating tangent to an edge-tone characteristic obtained from the same model. Second harmonic generation was much enhanced by a reflection function representing stretched modes. Stagnation pressure and hot-wire speed measurements yielded profiles for a real jet that broadened greatly under acoustic excitation, with development of a subsidiary peak. Jet swing amplitudes and phases for different frequencies agreed with pressure gradient as the stimulating force, not velocity or negative displacement. A jet blowing a flute embouchure coupled to a nonreflecting, separately excited air column, produced signals that implied an overall jet transfer function consistent with the assumptions of velocity stimulation and injected jet current drive made in the computer simulation.