Using Navier–Stokes modeling to design a better recorder

Abstract

The recorder family consists of several instruments of varying musical compasses. A musical tone is established by blowing into the mouthpiece of the instrument and a standing pressure wave is formed in the resonator of the instrument. Blowing harder into the instrument can cause a transition from the original (lower frequency) note to a higher (frequency) note. This transition is often referred to as “regime-change.” Recorder players have told us that regime-change in the bass recorder can happen at significantly lower blowing speeds for notes at the lower end of its musical compass. In this talk, regime-change is studied using Navier–Stokes based modeling in simplified models of sopranino and bass recorders. We show how the geometry beneath the labium of the recorder can be modified in order to alter regime-change behavior and extend the blowing range of the lowest notes in the bass recorder. In addition, these computational results are verified through experimental studies using 3D printed recorders and dimensions inspired by the modeling results.