title: Inverse identification of the release location, temporal rates, and sensor alarming time of an airborne pollutant source.
abstract: With an accidental release of an airborne pollutant, it is always critical to know where, when, and how the pollutant has been released. Then, emergency measures can be scientifically advised to prevent any possible harm. This investigation proposes an inverse model to identify the release location, the temporal rate profile, and the sensor alarming time from the start of a pollutant release. The first step is to implement the inverse operation to the cause-effect matrix to obtain the release rate profiles for discrete candidate scenarios with concentration information provided by one sensor. The second step is to interpret the occurrence probability of each solution in the first step with the Bayesian model by matching the concentration at the other sensor. The proposed model was applied to identify a single pollutant source in a two-dimensional enclosure using measurement data and in a three-dimensional aircraft cabin with simulated data. The results show that the model is able to correctly determine the pollutant source location, the temporal rate profile, and the sensor alarming time. The known conditions for input into the inverse model include a steady flow field and the valid temporal concentrations at two different locations.
  
  
  CONCLUSIONS
  The proposed inverse model can tell where, when, and how a gaseous pollutant has been accidently released based on the monitoring concentrations measured by two sensors. This methodology can be useful for providing emergency protection to indoor occupants.
authors.affiliation: School of Civil Engineering, Dalian University of Technology (DUT), Dalian, China.
authors.forename: T
authors.initials: T
authors.lastname: Zhang
authors.affiliation: School of Civil Engineering, Dalian University of Technology (DUT), Dalian, China.
authors.forename: H
authors.initials: H
authors.lastname: Zhou
authors.affiliation: School of Civil Engineering, Dalian University of Technology (DUT), Dalian, China.
authors.forename: S
authors.initials: S
authors.lastname: Wang
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor; D000401:Aircraft; D008962:Models, Theoretical; D013997:Time Factors
chemical_list: D000393:Air Pollutants
keywords: Bayesian probability; Inverse matrix; Inverse modeling; Release rate quantification; Sensor alarm time; Source identification