Characterizing transportation of indoor gaseous contaminant using the state space method

This paper employs the state space method to characterize transportation of indoor gaseous pollutant in steady airflow field. From the differential equations governing contaminant transportation in space, the state space equation for transportation is proposed and the analytical solution is obtained. In the method, the matrix covering hologram of the transportation is derived. The state space equation is validated with the analytic solution for the case of the simultaneous transportation of the pollution for piston flow. Similarly, the concentration from the proposed method for a 2-D case also agrees well with the result from CFD method based on the experimentally validated flow field. Based upon the analytic solution of the state equation, it is easily known that the influence of the initial concentration distribution and the pollution source on the concentration at the specific point. In addition, assisted by Chen’s zero equation turbulence model , the concentration field for a 3-D case is simulated by the presented method. It is found that there exists a regular stage at which the relative effect of the initial concentration distribution and the source on the concentration field will not change with time.