Derivation of drag and lift force and torque coefficients for non-spherical particles in flows

摘要

This paper derives and validates a new framework to predict the drag and lift coefficients as well as the torque coefficients for four non-spherical particle shapes in a flow with a wide range of flow Re and rotational Re numbers. Correlations are proposed for the drag force, the lift force, the pitching torque, and the torque caused by the rotation of the particle. Each of the correlations depends on Re number, the dimensionless rotation and the angle of incidence between the particle and the direction of the local fluid velocity. The fit parameters in the correlations for each of the particle shapes are determined by performing a large number of " true" DNS simulations of four different types of particles. The true DNS simulations are carried out with an improved mirroring immersed boundary method. The resulting correlations for the forces and the torques are suitable to be used in Eulerian-Lagrangian simulations, where an accurate prediction of the forces and torques is required to determine the motion of the particles.