Recently, flapping wing aerodynamics has attracted scientists and researchers to increase their efforts to understand it as the interest of designing micro-aerial vehicles (MAVs) increases. The objective of this study is to analyze flow over plunging airfoil with various values of reduced frequency (k), plunging amplitude (h), and non-dimensional plunge velocity (kh) and examine their effects on the mean thrust, mean power coefficients, and propulsive efficiency in order to obtain the maximum propulsive efficiency for designing the micro-aerial vehicles (MAVs). The study has been conducted considering a NACA0012 airfoil undergoing pure plunging motion at a Reynolds number of 20,000. A commercial CFD software Ansys CFX has been used for this study.

With the range of k and h chosen in this study, the result shows that the highest propulsive efficiency is 0.281 which happens when k = 2, and h = 0.175; The mean thrust coefficient is 0.0539, and the mean power coefficient is 0.192 with the same value of k and h. Moreover, it appears from the study that the propulsive efficiency varies with both k and kh. In the design of MAVs, it is desirable to find the best combination of k and h to achieve optimum propulsive efficiency.