3D particle position determination and correction at high particle densities

Abstract

The method of Iterative Particle Reconstruction (IPR), introduced by Wieneke in 2013, constitutes a major step towards Lagrangian Particle Tracking of densely seeded flows (Schanz et al. 2016). This work presents the advanced Iterative Particle Reconstruction method that was recently published in Experiments in Fluids (Jahn et al. 2021) and additionally aims to quantify the abilities of the method to correct for misplaced particle positions e.g. by biased triangulation or the predictive step of the Shake-The-Box scheme. The former part details numerous approaches to enhance the original IPR working principle. Most of them are easy to implement, come at low computational cost and, in combination, nearly triple the processable particle image densities. The updated method is proven to be fast, accurate and robust against image noise and other imaging artifacts. The latter will allow to derive guidelines for the layout of experiments in terms of the required acquisition frequency as a function of the expected Lagrangian accelerations in order to guarantee reliable particle tracking. Furthermore, an a-posteriori approach for quantifying the impact of particle image overlap situations on the achievable position accuracy and corresponding correction methods will be discussed