A robust trivariate approach for characterizing the primary particle size distribution of soot aggregates using time-resolved laser-induced incandescence

This study proposes a new trivariate retrieval method based on a moderate-fluence laser-induced incandescence (LII) model. By changing the undesirable mathematical properties present in our previous work, this upgraded new method is able to obtain robust estimates of the two primary particle size distribution parameters and one assembled parameter, and still maintains the advantage of not requiring prior knowledge of thermal accommodation coefficient and aggregate structure. The robustness of the upgraded method is verified on a large number of numerical results, as evidenced by significantly improved retrieval accuracy and substantially reduced estimation uncertainty. The generality of the upgrade method is demonstrated over a large range of three variables. Furthermore, the influence of several key factors (the number of shots used for averaging noisy LII signal, the intensity ratio of the measurement termination, and the sublimation sub-model error) on the retrieval results of the upgraded method is investigated numerically.