Woodwind flue instruments act acoustically as pipes open at both ends

Evidence

Other musical instruments which have an air reed sound source include the recorder and the flute. Useful additional material on woodwind flue instruments can be found in Benade (1976) and Fletcher and Rossing (1999). The air reed action is controlled by oscillatory changes in flow of air in and out of the flue (see Figure 4.16), often referred to as a “flow-controlled valve,” and therefore there must be a velocity antinode and a pressure node. Hence the flue end of the pipe is acting as an open end, and woodwind flue instruments act acousti­ cally as pipes open at both ends (see Figure 4.18). — David Howard, Jamie Angus, coustics and Psychoacoustics, 1214

Other musical instruments that have an air reed sound source include the recorder and the flute. … The air reed action is controlled by oscillatory changes in flow of air in and out of the flue (see Figure 4.16), often referred to as a “flow-controlled valve,” and therefore there must be a velocity antinode and a pressure node. Hence the flue end of the pipe is acting as an open end, and woodwind flue instruments act acoustically as pipes open at both ends (see Figure 4.18). — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1186

Categorization

• DEFINE: Explains the ‘flow-controlled valve’ concept and why the flue end counts as an open end, a core acoustic definition.
• XREF: Connects to other musical instruments chapters and Equation 4.8 / Figure 3.3 modal physics in this same book. — connects to: Open and stopped organ pipes correspond to open-open and open-closed acoustic tubes. — David Howard, Jamie Angus, coustics and Psychoacoustics, 1181; Reed-driven woodwinds act as stopped pipes while flute-type reeds act as open pipes. — David Howard, Jamie Angus, coustics and Psychoacoustics, 1236; Organ flue pipes divide into open-open and open-closed acoustic types — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1152 (+4 more)
• corroborated: 2 independent passages support this claim — David Howard, Jamie Angus, coustics and Psychoacoustics, 1214; David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1186

Broader Connections

• Reed pipes behave as stopped-end resonators, unlike open-ended flue pipes #corroborates (0.90) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1205
• Reed-driven woodwinds act as stopped pipes while flute-type reeds act as open pipes. #qualifies (0.85) — David Howard, Jamie Angus, coustics and Psychoacoustics, 1236
• Organ flue pipes divide into open-open and open-closed acoustic types #expands (0.80) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1152
• An open pipe end only reflects sound when an impedance mismatch exists there #qualifies (0.75)