THREE-DIMENSIONAL AIR QUALITY ASSESSMENT SIMULATIONS INSIDE SKY TRAIN PLATFORM WITH AIRFLOW OBSTACLES ON HEAVY TRAFFIC ROAD

Abstract

Air pollutant levels in Bangkok are generally high in street tunnels.  They are particularly elevated in almost closed street tunnels such as an area the Bangkok sky train platform with high traffic volume where dispersion is limited.  This area has no air quality measurement stations even though there is a high percentage of people living around this vicinity. We are interested to conduct a research the Bangkok sky train platform due to the traffic density and enormous polluted areas.  Therefore, we proposed a numerical modeling of air pollution concentration in sky train platform with airflow obstacles on heavy traffic road as an approximated solution of the three-dimensional advection-diffusion equation by using the finite difference methods.  Our research presentation is based on how air pollution model depends on the flow of air pollution and wind directions including the governing equation of the corresponding three-dimensional advection-diffusion equation is presented.  This also includes the initial condition and boundary conditions of traffic and polluted areas.  In order to illustrate the performance of the model, the numerical experiments are presented.  The comparison between the two methods and the simulations of air pollution control are proposed.  The three-dimensional advection-diffusion equation is solved by using the Forward Time, Centered Space (FTCS) and Forward Time, Backward Space (FTBS) schemes.  The results obtained indicate that the FTCS method provides a better result than FTBS method.  Furthermore, the proposed experimental variations of the boundary condition in the entrance gate do affect the air pollutant concentration of each floor.