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Characteristics of Particles and their Behaviour in Ventilation Air

The behaviour of particles in air flow is important for identifying those in various locations in ventilated space. The main reason for this study is to propose a new modelling concept to determine a realistic distribution of particles of different sizes in a space. The goal for this investigation is to divide particles into groups according to their behaviour in air and to improve the existing settling model. The growth of particle aerodynamic diameter in higher relative humidity is also presented.

Effect of central fans and in-duct filters on deposition rates of ulrafine and fine particles in an occupied townhouse

The deposition rates of particles in a town-house with a forced air circulation and in-duct filters have been calculated for that study. It appears that the use of central forced-air fan along with in-duct filters allows the reduction of particle concentration. And it is more effective than reducing ventilation by closing windows or making homes more insulated.

Comparison of indoor aerosol particle concentration and deposition in different ventilated rooms by numerical method

Indoor aerosol particles, their concentration and deposition in displacement, their movements in two ventilated rooms are compared numerically. For the simulation of particle tracks, the discrete trajectory model is adopted whereas the Eularian method is used for solving the continuous fluid flow.

Airborne particle concentrations in two classrooms with mixing and displacement ventilation

Airborne particle concentrations of 20 nm to 10 µm particles were studied in two similar classrooms in a school. One classroom was ventilated by mixing ventilation with supply air filtration and one by displacement ventilation without supply air filtratio

Multi-Zone Model Approach for Evaluating Particle Mass Transport in a Ventilated Room

The behaviour of solid contaminants in air flow is important for identifying those in variouslocations in ventilated space. The main reason for this study is to find out where different-sized particles can be found in a room using a simple particle-settling model. In this investigation two distinctive particle sizes are considered, i.e. 0.5 m and 10 m. Additionally, two different ventilation configurations are used to examine how this influences the particle concentration.

Numerical analysis of particle behaviors in indoor air using Lagrangian method

As particles in room air can cause lung diseases, it is important to study how they are transported and dispersed in buildings. This investigation numerically studied particle dispersion by using the Lagrangian approach. The turbulent airflow is solved by the RNG k-e model; and a discontinuous random walk (DRW) model is applied to account for the stochastic effect of particle movement in turbulent flow. The computed results agree reasonably well with the experimental data for particle dispersion in a wind tunnel.

A Lagrangian model for the dispersion of solid particles, in three-dimensional flow, using a CVFEM for the prediction of the continuous phase

A Lagrangian-Eulerian model for the dispersion of solid particles in a three-dimensional, incompressible, laminar or turbulent flow is reported, tested and partly validated. Prediction of the continuous phase is done by solving an Eulerian model using a Control-Volume Finite Element Method (CVFEM). A Lagrangian model is also applied, using alternatively an analytical and a Runge-Kutta 4th order method to obtain the particle trajectories. The effect of fluid turbulence upon particle dispersion is taken into consideration through a simple stochastic approach.

How ambient environment effects the migration of particulate matter?

The paper reviews the effect of environmental parameters on the migration of particulate matter. Themethodology involves simultaneous monitoring of particulate matter using dust monitor at indoor and outdoor locations along with the ambient environmental conditions. The study is of great significance as Particulate Matter (PM) has been reviewed in terms of particle count, which is more significant as compared to particle mass. In this paper, the variation of Indoor (PM) /Outdoor (PM) calculated on the basis of count are studied as a function of ambient wind speed, temperature and humidity.

Particle Transport in a Two-Zone Enclosure

Aerosol particles are one of the main causes to pollute indoor air. Reliable models for particletransport save time, money and help to reduce risk of health problems for occupants. In this work, we simulate particles transport in a two-zone enclosure with different particle characteristics. A statistically based analytical model is used for particles equilibrium whereas a Lagrangian model is employed to determine particle trajectories.

Measurement of aerosol deposition in bifurcating ducts with curved inlet

The quantitative knowledge gained from the assessment of particle deposition in ducts is importantto study, for example, the elimination of air leakage from duct systems with aerosolized sealant particles or to implement strategies of cleanliness of air ventilation systems. The study of particle deposition on the components of ventilation systems contributes also significantly to a better understanding of human exposure to particulate pollution. In this work we investigate deposition of aerosol particles in bifurcating ducts with a curved inlet segment.

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