Numerical analysis of non-spherical particles moment arm in particle-particle interactions and its impact on rotational motion

The particle-particle interaction of three-dimensional, non-spherical particles is thoroughly investigated using the sharp-interface curvilinear immersed boundary (CURVIB) method. Kinematic motion equations govern particle progression through a channel with particle-wall and particle-particle interactions. A threshold algorithm is used where a collision has occurred when the distance between the particle's surface nodes or the wall is less than the set threshold value. At the collision, the nodes less than the threshold are considered the contact points, where the average contact point locations and relative velocities are used to determine the moment arm and the rebounding translational and rotational velocity. Verification is achieved using a coefficient of restitution equal to one, confirming the constant total energy of interactions for the particles and wall collisions. Particle shapes include cubes, spheres, doughnuts, and irregular shapes. One particle is initially stationary in the middle of the channel, while a second and third particle is set with an arbitrary initial velocity to cause the particles to interact with the stationary particle. A series of simulations demonstrate the influence of the moment arm on the rotational motion of non-spherical particle-particle collisions. Knowing the effect of the moment arm on the rotational motion can lead to more precise predictions and control of particle behavior in fluid mechanics applications.