Micropolar fluids commonly represent the complex fluids with microstructure, for example, animal blood and liquid crystals. To understand the behavior of micropolar fluids and the role of micropolar parameters, different micropolar fluids models were implemented by user-defined function in the FLUENT software. The correctness of user-defined function programs was verified comparing to the analytical solution in the Poiseuille flow. Then, the hydrodynamic behavior was analyzed in the Poiseuille flow with a moving particle, slider bearing, and dam break. Numerical results show that microrotation viscosity weakens translational velocity while enhances the pressure of micropolar fluids, in addition, microrotation velocity decreases with the increase in angular viscosity.