The dynamic angle of repose was simulated by computational particle fluid dynamics (CPFD) when particles were continuously falling. CPFD simulation variables were fitted by comparing the angle of repose with the experimental data and P s (particle normal stress) variance. Using a fitted simulation, the effect of hopper height (H h ) and hopper inlet diameter (D in ) on the angle of repose was investigated. As H h increased, the angle of repose decreased up to the height at which the particle velocity reached terminal velocity. Also, as D in /D hopper decreased, the descending area of the particle was increased, following an increase in the angle of repose from 11 to 53 . The design of a hopper based on the obtained results shows that the particle discharge rate of the hopper can be increased by about 2.5 times.