Goodarz Ahmadi

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Three dimensional computational models of both sides of human nasal passages were developed to investigate the effect of septal deviation on the flow patterns and deposition of micro/nano-particles in the realistic human nasal airways before and after septoplasty. A series of coronal CT scan images from a live 25-year old nonsmoking male with septal(More)
Realistic 3-D models of the human nasal passages were developed pre and post virtual uncinectomy and Middle Meatal Antrostomy. A 3-D computational domain was constructed by a series of coronal CT scan images from a healthy subject. Then a virtual uncinectomy intervention and maxillary antrostomy were performed on the left nasal passage by removing the(More)
This article mainly concerns theoretical research on entropy generation influences due to heat transfer and flow in nanofluid suspensions. A conventional nanofluid of alumina-water (Al2O3-H2O) was considered as the fluid model. Due to the sensitivity of entropy to duct diameter, miniand microchannels with diameters of 3 mm and 0.05 mm were considered, and a(More)
In order to improve the dispersibility of multi-walled carbon nanotubes (MWCNT) in aqueous media, MWCNT were functionalized with tetrahydrofurfuryl polyethylene glycol (TFPEG) in a one-pot, fast and environmentally friendly method. To reduce defects and eliminate the acid-treatment stage, an electrophonic addition reaction under microwave irradiation was(More)
An experimental study concerning rapid flows of granular materials in a two dimensional planar granular Couette flow apparatus is performed. The device is capable of generating particulate flows in grain-inertia regime at different shearing rates and solid volume fractions. Multi-color spherical glass particles are sheared across an annular test-section for(More)
This study reports on a facile and economical method for the scalable synthesis of few-layered graphene sheets by the microwave-assisted functionalization. Herein, single-layered and few-layered graphene sheets were produced by dispersion and exfoliation of functionalized graphite in ethylene glycol. Thermal treatment was used to prepare pure graphene(More)
A finite volume-based computational model was developed to investigate the uniformity of the fluid flow across the hollow fiber membranes in blood oxygenation devices. A two-dimensional annular cross section of a blood oxygenation device including about 3,300 hollow fiber membranes was used in the computation model. The equations governing the steady(More)
Numerical simulations have been carried out on a model of the right passageway of an anonymous, adult male's nasal cavity, constructed from magnetic resonance imagery (MRI) scans. Steady, laminar, inspiratory flow was assumed to simulate inhalation. Analysis shows smoothly varying streamlines with a peak in velocity magnitude occurring in the nasal valves(More)
Laminar and turbulent mixed convection heat transfer of water/Cu nanofluids in a rectangular shallow cavity was studied utilizing a two-phase mixture model. The upper movable lid of the cavity was at a lower temperature compared to the bottom wall. Simulations were performed for Grashof numbers of 105 (laminar flow) and 1010 (turbulent flow) for Richardson(More)
Invasion percolation with trapping (IPT) and diffusion-limited aggregation (DLA) are simple fractal models, which are known to describe two-phase flow in porous media at well defined, but unphysical limits of the fluid properties and flow conditions. A decade ago, Fernandez, Rangel, and Rivero predicted a crossover from IPT (capillary fingering) to DLA(More)