LES and in-vitro experimental validation of flow around a teeth-shaped obstacle
Résumé
The current paper aims to provide numerical and experimental flow data relevant for physical modelling of human fricative sound production due to the interaction of airflow with the teeth. A simplified upper incisor-palate geometry is derived from typical morphological features. The geometry is inserted in a rectangular channel for which the width-to-height ratio yields 4. The obstruction degree due to the presence of the simplified upper incisor yields 70%. Numerical flow data are obtained from large eddy simulations. Experimental flow data are gathered from single-sensor anemometry on a rigid plaster print of the computational grid. Transverse velocity profiles are obtained downstream in the constricted area, i.e., from x = 0 up to x/h = 1.5 with h denoting the aperture height. The Reynolds number is set to 4000. The mean velocity profiles derived on simulated and measured data exhibit a strong asymmetry due to the presence of the obstruction. Nevertheless, significant differences appear with respect to the jet development, as e.g., quantified by the downstream evolution of the jet width or the appearance of significant turbulence intensities (>10%) at the teeth edge in the measured data whereas the simulated flow remains laminar.