Numerical simulation of freely falling plates

In this paper, 2-Dimension freely falling plates with different mass distributions are simulated by numerically solving the equations of motion coupling with the Navier-Stokes equations. With moving mesh, the motions related to different parameters are studied. The trajectories are identified and the unsteady dynamics are given by considering different dimensionless moments of inertia, and the initial falling angle and centroid positions. The results show that, except the three known classical trajectories:fluttering, tumbling, steady descent, we also observe two new motions. These motions are asymmetrical-fluttering and flutter-tumbling trajectories. They are caused by the centroid position deviating from the center of the plate and the dimensionless moment of inertia in the range of 0~0.95. These motions turn to the tumbling when the centroid position is beyond 0.13L. It indicates that the dimensionless moment of inertia and centroid position are important parameters in freely falling plates, but the physical mechanisms are different in falling motions. The present results can provide academic reference in study of low Reynolds number problems.