By revisiting the air distribution and bioaerosol dispersion in Ward 8A where the largest nosocomial severe acute respiratory syndrome (SARS) outbreak occurred in Hong Kong in 2003, we found an interesting phenomenon. Although all the cubicles were in 'positive pressure' towards the corridor, the virus-containing bioaerosols generated from the index patient's cubicle were still transmitted to o...

Based on CT medical images of ten volunteers, the 3D FE model of the upper airway was reconstructed by using the method of surface rendering. It is comparatively true that the established model reflects the actual anatomical configuration, and the airflow of the whole cavity is simulated numerically and analyzed by the FE method. From the results of the numerical simulation, the airflow distrib...

The objective of this paper is to develop a computational model of human nasal cavity from computed tomography (CT) scans using MIMICS software. Computational fluid dynamic techniques were employed to understand nasal airflow. Gambit and Fluent software was used to perform CFD simulation. Velocity profiles, iteration plots, pressure distribution, streamline and pathline patterns for steady, lam...

In addition to low-level windshear (below 1600 feet), low-level turbulence could also adversely affect arriving/departing aircraft at the airport. Turbulent airflow may occur in clear-air/non-rainy weather conditions, e.g. terrain effect at the Hong Kong International Airport (HKIA) or building’s disruptions at Haneda Airport (Tokyo International Airport) in Japan. Such airflow disturbances cou...

Obstructive lung diseases in the lower airways are a leading health concern worldwide. To improve our understanding of the pathophysiology of lower airways, we studied airflow characteristics in the lung between the 8th and the 14th generations using a three-dimensional computational fluid dynamics model, where we compared normal and obstructed airways for a range of breathing conditions. We em...

OBJECTIVE To investigate the aerodynamic consequences of conservative unilateral inferior turbinate reduction using computational fluid dynamics methods to accomplish detailed nasal airflow simulations. DESIGN A high-resolution, finite-element mesh of the nasal airway was constructed from magnetic resonance imaging data of a healthy man. Steady-state, inspiratory airflow simulations were cond...

Biomass and microbial activity in backwashing processes of a biofilter for tertiary treatment were investigated. The microbial groups revealed new distribution along the biofilter depth after low flow rate backwashing for a short time. Then the start-up process was accelerated by backwashing. The biomass profile and microbial activity profile both varying with depth before and after backwashing...