In the civil market, an increase in the demand for drone technology has given rise to rotor blade design. Much research has to undergo to enhance the efficiency of propellers. In this research, we want to improve the propeller design efficiency in terms of flight endurance. The main goal is in the variation of axial separation by using computational fluid dynamics in OpenFOAM. We found that the variation of distance between two propellers has improved overall efficiency significantly during computational analysis. At the lowest separation, the interference disturbance created by the lower propeller affects the upper propeller performance by lowering total thrust. However, if we increase the distance, the lower propeller faces the downwash created by the upper propeller resulting in the efficiency loss of the lower one. One can increase or decrease the axial separation, but the overall efficiency would remain the same. Hence, it has been found that at 0.65z/R, we have the maximum efficiency.