Evaluation of the Accuracy of Trajectory Time Integration Used for Lagrangian Particle Tracking

The LPT (Lagrangian particle tracking) is a fluid simulation technique that monitors particle movement in a flow field. Numerical errors such as truncation and rounding off can affect trajectory time integrations. Particle tracking is crucial for studying aerosol behavior near a surface, such as filter fibers, where airflow has steep spatial velocity gradients and noticeable temporal velocity fluctuations. In this research, the accuracy of six different numerical methods for solving the Lagrangian particle motion equation were compared. The impact of floating-point and flow curvature on particle capture by a circular cylinder collector were also studied. As the result, it was found that the accuracy of the methods was significantly influenced by floating-point precision. However, a smaller time step did not always imply greater calculation accuracy. The accuracy of numerical methods was also greatly affected by a flow curvature. A low-order method sometimes can be a better choice for lower numerical precision computations.