Simultaneous determination of the position, release time and mass release rate of an unknown gas emission source in short-term emissions by inverse problem

© 2022 The Author(s)This article proposes a protocol for the simultaneous determination of the position, release time and mass release rate of an unknown gas emission source from experimental data in the form of an inverse problem, since these are the main variables in the short duration release of pollutants. Records of pollutant concentration and of measurement time (with their inherent errors) carried out at two measuring stations are the input data for the inverse problem. The actions of the protocol are divided into two well-differentiated stages. In the first, the simulations are started for each iteration, the functionals are calculated to program the next iteration, setting the new values of measurement time and the distance of the emission source in downwind direction with respect to the measuring stations by comparing the simulated and experimental values, and so on until reaching the final solution. In the second, an analogous procedure is followed until the mass rate and the emission source position is obtained. In addition, it has been necessary to define a new coefficient that relates the effect of dispersion in the measurement time, the distance in the downwind direction and the atmospheric stability categories. The reliability of the proposed protocol is checked by means of a problem whose parameters are known a priori. First, the direct problem is solved to obtain the values of contaminant concentration and the measurement time of the stations. These variables are then affected by random errors of up to 2% to provide the input data for the inverse problem. In all the examples shown in this work, solutions have been obtained that can be considered very successful in this field of engineering.