TY - JOUR
T1 - Hovering efficiency comparison of rotary and flapping flight for rigid rectangular wings via dimensionless multi-objective optimization
AU - Bayiz, Yagiz
AU - Ghanaatpishe, Mohammad
AU - Fathy, Hosam
AU - Cheng, Bo
N1 - Publisher Copyright:
© 2018 IOP Publishing Ltd.
PY - 2018/5/8
Y1 - 2018/5/8
N2 - In this work, a multi-objective optimization framework is developed for optimizing low Reynolds number (Re) hovering flight. This framework is then applied to compare the efficiency of rigid revolving and flapping wings with rectangular shape under varying Re and Rossby number (Ro, or aspect ratio). The proposed framework is capable of generating sets of optimal solutions and Pareto fronts for maximizing the lift coefficient and minimizing the power coefficient in dimensionless space, explicitly revealing the trade-off between lift generation and power consumption. The results indicate that revolving wings are more efficient when the required average lift coefficient CL is low (<1 for Re = 100 and <1.6 for Re = 8000), while flapping wings are more efficient in achieving higher CL. With the dimensionless power loading as the single-objective performance measure to be maximized, rotary flight is more efficient than flapping wings for Re > 100 regardless of the amount of energy storage assumed in the flapping wing actuation mechanism, while flapping flight is more efficient for Re < 100. It is observed that wings with low Ro perform better when higher cL is needed, whereas higher Ro cases are more efficient at cL < 0.9 regions. However, for the selected geometry and Re, the efficiency is weakly dependent on Ro when the dimensionless power loading is maximized.
AB - In this work, a multi-objective optimization framework is developed for optimizing low Reynolds number (Re) hovering flight. This framework is then applied to compare the efficiency of rigid revolving and flapping wings with rectangular shape under varying Re and Rossby number (Ro, or aspect ratio). The proposed framework is capable of generating sets of optimal solutions and Pareto fronts for maximizing the lift coefficient and minimizing the power coefficient in dimensionless space, explicitly revealing the trade-off between lift generation and power consumption. The results indicate that revolving wings are more efficient when the required average lift coefficient CL is low (<1 for Re = 100 and <1.6 for Re = 8000), while flapping wings are more efficient in achieving higher CL. With the dimensionless power loading as the single-objective performance measure to be maximized, rotary flight is more efficient than flapping wings for Re > 100 regardless of the amount of energy storage assumed in the flapping wing actuation mechanism, while flapping flight is more efficient for Re < 100. It is observed that wings with low Ro perform better when higher cL is needed, whereas higher Ro cases are more efficient at cL < 0.9 regions. However, for the selected geometry and Re, the efficiency is weakly dependent on Ro when the dimensionless power loading is maximized.
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U2 - 10.1088/1748-3190/aab801
DO - 10.1088/1748-3190/aab801
M3 - Article
C2 - 29557347
AN - SCOPUS:85047251103
SN - 1748-3182
VL - 13
JO - Bioinspiration and Biomimetics
JF - Bioinspiration and Biomimetics
IS - 4
M1 - 046002
ER -