Numerical Analysis On Movement Of Indoor Particulate Matter

It is very meaningful to investigate the indoor particle distribution and movement for improving indoor air quality (IAQ) and promoting indoor environment for sustainable development. Currently, theoretical study on indoor particulate matter distribution has no perfect theories or means. Furthermore, experimental investigation and the results in this field are very limited. There is no systematic scientific data provided for improving IAQ. Since 20 century 60s, the numerical simulation, which based on computational fluid dynamics, has become one of the pillars during the theoretical analyses, experimental studies and numerical calculation of the hydrodynamics field. Computational fluid dynamics (CFD) can simulate and predict the physical details of indoor particulate matter, such as velocity field and concentration field.This paper presented a model of three-dimensional geometry to predict indoor particle's distribution and influencing factors by using numerical calculation. The gas-solid flow in experimental chamber was studied by using CFD software CFX10.0. It was divided into four parts. Firstly, according to the building, layout, distribution of pollutants and air conditioning system's airflow, a reasonable prediction model was founded. Secondly, two-phase flow of experimental chamber was discussed thoroughly. Then three basic multiphase models are established, that is, the single-fluid model, the two-fluid model and the dispersion particle group trajectory model. Again, based on the Euler and Lagrange's two calculation methods and the three models, indoor particle concentration and other physical parameters was gained for every model by using CFX10.0. The three-dimensional simulation results was expressed by using visualization tools, and the indoor flue gas distribution and particle flow characteristics are demonstrated by using animation. Finally, the numerical results were analyzed, compared with the previous results to verify the feasibility of the method and the accuracy of results, and the conclusion was given.This study involved a three-dimensional multiphase model, numerical calculation, the mesh generation technology, turbulence model and so on. Some useful explorations have been found for the three-dimensional mathematical model room. The result shows that study on indoor particle numerical has practical value for particle distribution prediction, the conclusion is somewhat accurate. Single-fluid model in Euler way and dispersion particle group trajectory model in Lagrange way are better for indoor gas-solid flow's research. There is a close relationship between the indoor particle's distribution and indoor air movement. Indoor pollution's distribution and particle's movement are effected by indoor air movement. Solid phase has lightly effect on gas, but gas affects particle heavily. Indoor air movement is a typical turbulent flow, and the turbulent kinetic energy maximum in the rate of mutation, such as jet outlet, indoor corner and air circulates badly, where convection easily transfer for produce of large whirlpool and accumulation of particulate matter.