Transportation and deposition of droplets from a nebulizer within the nasal cavity are dependent on the existing airflow patterns. Figure 1 illustrates the inspired air profile, which is the dominant airflow pattern in the cavity. Inspired air patterns largely determine where and how drug deposition in the nasal cavity occurs. Relatively low flow amounts are observed in the olfactory region (<1...

Influence of externally forced initial flow conditions on axisymmetric cavity shear layer were studied. A sinusoidally heated strip upstream of the cavity excited Tollmien-Schlichting waves which, after amplification by the boundary layer, were introduced to the cavity shear layer. By choosing forcing frequencies within the range of shear layer receptivity, it was possible to control frequency ...

Cavity ring-down spectroscopy is applied to the liquid phase by placing the target solution directly into the optical cavity. We demonstrate that solutions in the cavity can be stirred and more importantly monitored in a flow. We report a minimum detectable absorption of 10(-6) cm(-1) for a range of organic solvents. This detection limit corresponds to picomolar concentrations for strong absorb...

Computations and experimental validation were conducted to obtain flow field over an axisymmetric cavity with different front wall inclinations at a freestream Mach number of 2.0. Flow oscillation in and around the cavities may incur a damaging effect on the stable flight of the aircraft and store releases. Aero-acoustic from the oscillating flow induces vibration in the local bay structure and...

This paper presents a detailed numerical simulation of the fluid flow characteristics of a synthetic jet. The fluid motion is caused by an oscillating piston within a circular channel which is connected to a larger cavity. The oscillating piston utilized a sawtooth forcing profile, and the solution encompassed the channel geometry, the cavity, and the fluid domain external to the cavity. Moment...

Optical power flow along an active cavity having net gain can differ dramatically from that in a passive cavity. We report the first observation of Poynting’s vector reversal in an active cavity under scattering boundary conditions. At a sub-lasing gain, which we call Poynting’s threshold, a null develops in Poynting’s vector, which divides the cavity into sections with oppositely directed ener...

This study determines the mean and fluctuating pressures for flow through a rectangular shallow cavity (ratio between length depth = 2.43, 4.43, 6.14; ratio width 0.5, 1.0, 2.0) at Mach number of 0.64 in blowdown transonic wind tunnel. A amplitude modulation analysis is used post-processing pressure signals. The spectral (wavelet) shows intermittent behavior discrete Rossiter–Heller modes. corr...