This paper presents numerical procedures for a coupled scheme that combines immersed boundary and discrete element methods to simulate two-dimensional fluid and particle motion. We simulated the dead-end, constant-flux microfiltration of dispersed particles and investigated the effect of hydrodynamic interactions between the fluid and particles on the transmembrane pressure. The permeation of a single particle through a pore was first simulated to obtain the fundamental characteristics of transmembrane pressure behavior. The effects of the particle dispersion volume fraction and the pore size on the transmembrane pressure were then investigated. The results show that the transmembrane pressure increases and fluctuates even in the absence of membrane fouling when a particle penetrates the pore. Transmembrane pressure behavior is also significantly affected by the number of particles within the pore and the location of particles around the pore.