in the present study a quasi 2-d numerical model is developed for calculating air concentration distribution in rapid flows. the model solves air continuity equation (convection diffusion equation) in the whole flow domain. this solution is then coupled with calculations of the free surface in which air content in the flow is also considered. to verify the model, its results are compared with a...

This paper's numerical study, which applies the finite volume approach and SIMPLE algorithm, aims to dynamically analyze airflow through a channel with Z-obstacles. Three distinct models were used place Z-barriers inside channel. According Demartini et al.'s model (2004) as depicted in example A from present analysis, first Z-barrier (fin) is attached top wall (heated) second (baffle) bottom (i...

The study shows an experimental investigation for a solar air collector with single pass by adding rectangular baffles different positions inside the channel. aim of this is to improve thermal efficiency collector, and that through testing four cases (mode 1, 2, 3, 4). was done under operating conditions changing mass flow rates baffles. results show effectiveness in improving also proved affec...

A numerical model is developed to simulate the transport phenomena in the flow channel between parallel plates with porous and non-porous (or impermeable) walls. The continuity and momentum equations were solved first, assuming the wall Reynolds number in the range of with the suction or injection of air at a speed equal to the uniform inlet velocity. The results show that at constant inlet and...

the present study compared simple thermal indices and the indices derived from energy budget models in the northwest of iran. for this purpose, the air temperature, solar radiation, relative humidity, cloud, cover and wind speed of 13 meteorological stations in the northwest of iran during the  the period of 1986 to 2007 were selected for comparison. the results which were extracted using biokl...

Ex situ experiments were conducted to study water droplet dynamics in Proton Exchange Membrane Fuel Cell (PEMFC) gas channels with different trapezoid channel open angles and GDL materials under controlled air velocities (0.48e7.23 m s 1). High speed videos revealed that the droplets interacted with the channel walls at lower air velocities (0.48e4 m s 1) and led to channel corner filling depen...

− A mobile station has been designed to monitor the air quality. Several of those stations are to be installed on the rooftop of taxis and buses in order to build a real time map of the air quality of a city. The modules are equipped with gas concentration measurement modules for 5 different gases (CO, NO2, O3, SO2, and CO2), GPS receivers for localization, GSM/GPRS modules for communication an...