This study investigates the effect of air inlet size on (i) the flowfield generated in a dry powder inhaler, and (ii) the device-specific resistance, and the subsequent effect on powder deagglomeration. Computational fluid dynamics (CFD) analysis was used to simulate the flowfield generated in an Aerolizer with different air inlet sizes at 30, 45, and 60 l/min. Dispersion performance of the mod...

Moving dots can evoke a percept of the spatial structure of a three-dimensional object in the absence of other visual cues. This phenomenon, called structure from motion (SFM), suggests that the motion flowfield represented in the dorsal stream can form the basis of object recognition performed in the ventral stream. SFM processing is likely to contribute to object perception whenever there is ...

This paper presents steady-state (viscous) and timeaccurate (inviscid) numerical solutions of the flowfield inside the Virginia Tech Hypersonic Wind Tunnel (VTHST) with a Mach 4 nozzle. The numerical solutions are obtained using a computational fluid dynamics (CFD) solver named GASP. Comparisons between the steady-state CFD solutions and available experimental data are also presented in this pa...

This paper describes a dynamic controller for rotorcraft landing and hovering in ground effect using feedback control based on flowfield estimation. The rotor downwash in ground effect is represented using a ring-source potential flow model selected for real-time use. Experimental verification of the flow model is also presented. A nonlinear dynamic model of the rotorcraft in ground effect is p...

Amodular particle–continuum numerical method is used to simulate steady-state hypersonic flow over a hollowcylinder-flare geometry. The resulting flowfield involves a mixture of rarefied nonequilibrium flow and high-density continuum flow. The hybrid particle–continuummethod loosely couples direct simulationMonte Carlo andNavier– Stokes methods, which operate in different regions, use different...

We report the application of molecular tagging velocimetry (MTV) toward two-component velocimetry as demonstrated in an underexpanded free jet flowfield. Two variants of the MTV technique are presented: 1) electronic excitation of seeded nitric oxide (NO) with gated fluorescence imaging (fluorescence lifetime) and 2) photodissociation of seeded NO2 followed by NO fluorescence imaging (NO2 photo...

Visual transformations are often employed to achieve size and rotation invariances in computational approaches to vision. Nature appears to have adopted a similar strategy: research workers studying biological vision systems have known for over a decade that a particular spatial transformation appears to be applied to the visual signals that are conveyed between the retina and the primary visua...

A Monte Carlo ray trace radiation model is presented for the determination of radiative properties of Al2O3 particles in the high altitude plume of a solid propellant rocket. A polydisperse distribution of non-gray particles is modeled as an emitting, absorbing and scattering medium of arbitrary optical thickness. Strong two-way coupling is allowed between radiation and flowfield calculations, ...