Reconstruction of aeolian sand grain saltation based on inter-frame particle tracking algorithm and geometric constraints

Abstract

The saltation trajectories of sand grains serve as a direct indicator of the two-phase interaction during the process of aeolian sand transport. Particle Tracking Velocimetry (PTV) has been employed to reconstruct these saltation trajectories. However, traditional PTV algorithms encounter difficulties due to the randomness and three-dimensional (3D) characteristics of sand-grain motion, which impede the complete reconstruction of saltation trajectories. This paper puts forward a PTV algorithm grounded on the Voronoi diagram (VD). It is demonstrated that this algorithm exhibits higher accuracy compared to other VD-based PTV algorithms. A homemade algorithm called Dual Angular Constraint (DAC) is introduced to support the proposed PTV algorithm, ensuring the most comprehensive reconstruction of saltation trajectories. Through a test using 3D artificial particle flows, the robustness of the proposed PTV algorithm in 3D space is validated. This validation offers the feasibility for the visualization of sand-grain motion in practical applications, accompanied by efficient and accurate kinematic analysis.