Numerical study has been performed to examine the characteristics of flows inside a square channel generated by a two-stage electrohydrodynamic (EHD) pump with electrodes mounted in various orientations. Since flow visualization is very challenging to implement in an experimental study of EHD flows, no visual result has been reported from the previous studies in this particular case. Thus the present study is specifically aimed at providing additional insight to the flow field inside the channel through visualization of the numerical results obtained. Clearly, the present results are very helpful in shedding light to the flow behavior inside the channel. In addition, the numerical results are used to confirm the findings from the previous experimental work that EHD pump with offset electrodes produces more mixing of flow inside the channel. Furthermore, the results show that one can further improve the performance of the pump when its two stages are operated in uneven voltages.