Computational fluid dynamics—Discrete element method simulation of the contact forces between microcapsules using a speed-up method with reduced Young's modulus

Abstract The small time-step due to the small size of microcapsules using the discrete element method (DEM) requires a significant number of computations when analyzing the force condition of microcapsules for mixing self-healing concrete. In this study, a speed-up method with a reduced Young's modulus is proposed to correct the particle contact force after establishing the relationship between the maximum contact force and the Young's modulus of particles in the collision process by using theoretical derivations and data fitting. The proposed method was verified using a stirred box model with the DEM and a stirred tank model with computational fluid dynamics–DEM. The effects of different particle numbers, impeller speeds, and time-step sizes on the accuracy of the proposed method were investigated. The results demonstrated the feasibility of analyzing the maximum contact force between particles using the speed-up method with a reduced Young's modulus.