Study of unvoiced fricative speech production: Influence of initial conditions on flow development

Human unvoiced fricative speech sounds such as [s] and [f] are produced by a complex fluid-structure interaction. Indeed, a moderate Reynolds number (100 ≤ Re ≤ 10000) turbulent jet is issued from a constriction somewhere in the vocal tract formed between the hard palate and an articulator such as tongue, teeth, or lips. By using simplified in-vitro replicas representing parts of the human vocal tract, some physical phenomena relevant to the unvoiced fricative speech production can be reproduced and more easily understood. The current study focuses on the influence of initial conditions on flow development by performing flow measurements and Large Eddy Simulation on a rectangular channel containing a tooth-shaped obstacle.