Response of an artificially blown clarinet to different blowing pressure profiles.
Using an artificial mouth with an accurate pressure control, the onset of the pressure oscillations inside the mouthpiece of a simplified clarinet is studied experimentally. Two time profiles are used for the blowing pressure: in a first set of experiments the pressure is increased at constant rates, then decreased at the same rate. In a second set of experiments the pressure rises at a constant rate and is then kept constant for an arbitrary period of time. In both cases the experiments are repeated for different increase rates. Numerical simulations using a simplified clarinet model blown with a constantly increasing mouth pressure are compared to the oscillating pressure obtained inside the mouthpiece. Both show that the beginning of the oscillations appears at a higher pressure values than the theoretical static threshold pressure, a manifestation of bifurcation delay. Experiments performed using an interrupted increase in mouth pressure show that the beginning of the oscillation occurs close to the stop in the increase of the pressure. Experimental results also highlight that the speed of the onset transient of the sound is roughly the same, independently of the duration of the increase phase of the blowing pressure.
LUNAM Université, Université du Maine, Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6613, Laboratoire d'Acoustique, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France.
Baptiste
B
Bergeot
LUNAM Université, Université du Maine, Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6613, Laboratoire d'Acoustique, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France.
André
A
Almeida
LUNAM Université, Université du Maine, Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6613, Laboratoire d'Acoustique, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France.
Bruno
B
Gazengel
Laboratoire de Mécanique et d'Acoustique, Centre National de la Recherche Scientifique, Unité Propre de Recherche 7051, Aix-Marseille Univ, Centrale Marseille, F-13402 Cedex 20, France.
Christophe
C
Vergez
Laboratoire d'Astrophysique de Marseille (Laboratoire d'Astrophysique de Marseille, Centre National de la Recherche Scientifique, Institut National des Sciences de l'Univers, Unité Propre de Recherche 7326), Po^le de l'Étoile Site de Cha^teau-Gombert/38, rue Frédéric Joliot-Curie 13388 Marseille Cedex 13, France.
Didier
D
Ferrand
D000162:Acoustics; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D006801:Humans; D008953:Models, Anatomic; D008962:Models, Theoretical; D009038:Motion; D009055:Mouth / Q000033:anatomy & histology / Q000502:physiology*; D009146:Music; D009716:Numerical Analysis, Computer-Assisted; D009991:Oscillometry; D011312:Pressure; D013997:Time Factors; D014732:Vibration