Investigating longitudinal moment characteristics of flapping-wing MAV in wind tunnel

To our knowledge, we are among the first in China to perform wind-tunnel investigation of flapping-wing micro air vehicle (FMAV). In this paper, we present the results of our investigation of FMAV longitudinal moment characteristics in the purposefully-designed NWPU FMAV wind-tunnel. In the full paper, we explain our investigation in some detail; in this abstract, we just add some pertinent remarks to listing the two topics of explanation. The first topic is: the purposefully-designed equipment and model. Its subtopics are: wind-tunnel (subtopic 1.1), strain balance (subtopic 1.2), acquisition systems and their control equipment (subtopic 1.3), and experimental model (subtopic 1.4). In the first topic, we give Figs.1 through 3 showing the wind tunnel, experimental mechanisms and the wing. The second topic is: experimental results and their analysis. In this topic, we analyze the influences respectively of angle of attack, flapping frequency and freestream velocity on FMAV longitudinal moment characteristics. Figs.5 and 6 in the full paper show that, when the angle of attack is small, the longitudinal moment coefficient of the FMAV presents linear variation with the angle of attack. Fig.7 shows that the longitudinal moment coefficient increases slightly with increasing flapping frequency. Fig.8 indicates that the longitudinal moment coefficient decreases with increasing freesteam coefficient. The analysis of experimental results shows that, when the freesteam velocity increases from 4 m/s to 10 m/s, the Reynolds number increases from 2.4 × 10⁴ to 5.5 × 10⁴, demonstrating that the Reynolds number has obvious influence on the longitudinal moment coefficient.