Pressure drop for adiabatic air-water flow through a time-varying constriction

The pressure drop for air-water flow within a vertical rigid channel containing a severe time-varying constriction is studied for different forcing frequencies f(c) is an element of{1, 6, 10} g Hz after water (0 up to 5 ml) is injected upstream. The pressure drop at the minimum aperture is observed experimentally and can be modeled with a quasi-steady one-dimensional approach and viscous mixing during the closing and opening phase. It is found that the flow can be regarded as gas dominated during the closing phase. During the opening phase, mixing enhances as f(c) > 1 Hz, which emphasizes the contribution of water and water droplets to the viscous mixture. Eventually, for f(c) = 10 Hz and greater water volumes (>= 3 ml), mixing is further increased so that the flow becomes homogeneous and turbulent during the opening phase. Assessed conditions are relevant to flow through the human glottis. Published by AIP Publishing.