الفهرس 
Introduction and Literature SurveyOnly 14 pages are availabe for public view
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Abstract
Todays, people spend most of their lives in the indoor environment. Indoor Air Quality (IAQ) has become more important to create healthy environment inside closed rooms. The present study investigates the flow field of particle-laden air flow through closed spaces. The numerical study is based on Euelrian-Lagrangian approach. In this approach, the gas phase is simulated using 3-D Reynolds Averaged Navier Stokes equations and particle tracking procedure is used to simulate solution of the solid phase. The gas phase turbulence is simulated using six turbulent models. These models are standard k-ε, RNG based k-ε, Low-Re k-ε, k-ω, extended k-ε (Chen-
Kim) and v2-f models. The Chen-Kim and v2-f models are implemented in the Fluent code using User Defined Functions (UDF) and User Defined Scalars (UDS), while the other models are available directly in the code. The boundary conditions, Reynolds stresses and particle-wall collisions are defined using UDF. One-way coupling approach is considered in the present work since, the solid mass loading ratio in polluted air is usually small. The model takes into account the effect of drag, gravity and lift forces on the particles motion. The experimental work is carried out by constructing a test rig, which is used to simulate a simple room. Studied turbulence models are validated against experimental data available in the literature for free, forced and mixed convection cases. This comparison is aimed to test the ability of each model in prediction of flow field inside closed spaces. Chen-Kim model gives a good prediction in the cases involving forced or mixed convection. Measurements of air velocity, temperature and solid concentration are performed at different air mass flow rate.
Comparison between model predictions and the present experimental results show good agreements. The present results indicate that the particle diameter has a great effect on the particles residence time and hence in the particles concentration inside closed spaces. Thus the smaller particle size has the longest residence time. Investigation of polluted air flow in closed spaces. The inlet opening location plays an important role in the air velocity distributions and change of particle concentration in ventilated rooms. Also, it is found that the inlet opening that is located in the breathing zone can reduce the particle concentration inside this room. At the same time, selection a suitable position of solid particles source inside the room has a direct effect on the particles concentration. Finally, it is clearly noticed that, the forced ventilation method gives the lower particle concentration faster than sucked ventilated method.