Estimation of aerosol source emission profiles in unsteady state

In this article, we describe a method to estimate the unknown flow rate of an unsteady particle source, starting from concentrations measurements in the far field. The method consists of two parts, which are the calibration phase and the estimation phase. The calibration phase is used to create a transfer function (called impedance) between a known source function (called reference source) and the corresponding concentration signal obtained in the far field. The second step consists in inverting the impedance for the concentration signal obtained for the unknown source, so as to estimate its flow rate. An experimental study allows validating the method. The tests are performed in an open ventilated cabin. The results show that the estimation method is satisfactory since the estimated source signal follows a similar tendency with respect to the actual flow. Furthermore, the difference between the total mass injected and its estimation is less than 1%.