A simplified geometric model of a bat wing was utilized to study its morphology and deformation, along with its aerodynamic characteristics, using computational fluid dynamics methods. A model was established with a parallelogram-shaped inner wing and a combined triangular outer wing. The wing deformations were categorized into four types:area variation, outer wing bending, chordwise cambering, and wing twisting. Two flight modes, slow and fast, were defined based on experimental data. The results demonstrate that the aerodynamic forces acting on the bat wing model in both slow and fast flight modes are similar in spatial-temporal distribution, with both lift and thrust generated during the downstroke phase. The forces during the upstroke phase are comparatively smaller. Thrust is generated entirely by the outer wing, whereas lift is generated by both the outer and the inner wings. Furthermore, it was found that slow flight achieves velocity adaptation primarily through angle-of-attack adjustments, supplemented by minor flapping frequency modulation. In contrast, fast flight relies predominantly on frequency adjustments, with fine-tuning of the angle of attack to maintain force equilibrium across different speeds. The analysis of the aerodynamic forces acting on the deforming bat wing contributes to a more profound comprehension of the mysteries of bat flight.
ZHU Bowen
,
YU Yongliang
. Aerodynamic characteristics of deforming bat-like wing in forward flight[J]. Journal of University of Chinese Academy of Sciences, 2025
, 42(3)
: 304
-314
.
DOI: 10.7523/j.ucas.2023.051
[1] Yu Y L, Guan Z W. Learning from bat: aerodynamics of actively morphing wing[J]. Theoretical and Applied Mechanics Letters, 2015, 5(1): 13-15. DOI: 10.1016/j.taml.2015.01.009.
[2] 余永亮. 蝙蝠飞行的空气动力学研究进展[J]. 空气动力学学报, 2018, 36(1): 129-134. DOI: 10.7638/kqdlxxb-2017.0207.
[3] Norberg U M. Bat wing structures important for aerodynamics and rigidity (Mammalia, chiroptera)[J]. Zeitschrift Für Morphologie Der Tiere, 1972, 73(1): 45-61. DOI: 10. 1007/BF00418147.
[4] Norberg U M, Rayner J M V. Ecological morphology and flight in bats (Mammalia; Chiroptera): wing adaptations, flight performance, foraging strategy and echolocation[J]. Philosophical Transactions of the Royal Society of London B, Biological Sciences, 1987, 316(1179): 335-427. DOI: 10.1098/rstb.1987.0030.
[5] Rayner J M V, Aldridge H D J N. Three-dimensional reconstruction of animal flight paths and the turning flight of microchiropteran bats[J]. Journal of Experimental Biology, 1985, 118(1): 247-265. DOI: 10.1242/jeb.118.1.247.
[6] Hedenström A, Johansson L C, Wolf M, et al. Bat flight generates complex aerodynamic tracks[J]. Science, 2007, 316(5826): 894-897. DOI: 10.1126/science.1142281.
[7] Wolf M, Johansson L C, von Busse R, et al. Kinematics of flight and the relationship to the vortex wake of a Pallas’ long tongued bat (Glossophaga soricina)[J]. Journal of Experimental Biology, 2010, 213(12): 2142-2153. DOI: 10.1242/jeb.029777.
[8] Taha H E, Hajj M R, Beran P S. State-space representation of the unsteady aerodynamics of flapping flight[J]. Aerospace Science and Technology, 2014, 34(2): 1-11. DOI: 10.1016/j.ast.2014.01.011.
[9] Fan X Z, Swartz S, Breuer K. Power requirements for bat-inspired flapping flight with heavy, highly articulated and cambered wings[J]. Journal of the Royal Society, Interface, 2022, 19(194): 20220315. DOI: 10.1098/rsif.2022. 0315.
[10] Sihite E, Ghanem P, Salagame A, et al. Unsteady aerodynamic modeling of Aerobat using lifting line theory and Wagner’s function[C]//2022 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS). October 23-27, 2022, Kyoto, Japan. IEEE, 2022: 10493-10500. DOI: 10.1109/IROS47612.2022.9982125.
[11] Colorado J, Barrientos A, Rossi C, et al. Inertial attitude control of a bat-like morphing-wing air vehicle[J]. Bioinspiration & Biomimetics, 2013, 8(1): 016001. DOI: 10.1088/1748-3182/8/1/016001.
[12] Hoff J, Ramezani A, Chung S J, et al. Optimizing the structure and movement of a robotic bat with biological kinematic synergies[J]. The International Journal of Robotics Research, 2018, 37(10): 1233-1252. DOI: 10.1177/0278364918804654.
[13] Windes P, Fan X Z, Bender M, et al. A computational investigation of lift generation and power expenditure of Pratt’s roundleaf bat (Hipposideros pratti) in forward flight[J]. PLoS One, 2018, 13(11): e0207613. DOI: 10.1371/journal.pone.0207613.
[14] Windes P, Tafti D K, Müller R. Kinematic and aerodynamic analysis of a bat performing a turning-ascending maneuver[J]. Bioinspiration & Biomimetics, 2021, 16(1): 016019. DOI: 10.1088/1748-3190/abb78d.
[15] Sekhar S, Windes P, Fan X Z, et al. Canonical description of wing kinematics and dynamics for a straight flying insectivorous bat (Hipposideros pratti)[J]. PLoS One, 2019, 14(6): e0218672. DOI: 10.1371/journal.pone.0218672.
[16] Guan Z W, Yu Y L. Aerodynamic mechanism of forces generated by twisting model-wing in bat flapping flight[J]. Applied Mathematics and Mechanics, 2014, 35(12): 1607-1618. DOI: 10.1007/s10483-014-1882-6.
[17] Guan Z W, Yu Y L. Aerodynamics and mechanisms of elementary morphing models for flapping wing in forward flight of bat[J]. Applied Mathematics and Mechanics, 2015, 36(5):669-680. DOI: 10.1007/s10483-015-1931-7.
[18] Wang C Y, Liu Y, Xu D, et al. Aerodynamic performance of a bio-inspired flapping wing with local sweep morphing[J]. Physics of Fluids, 2022, 34(5): 051903. DOI: 10.1063/5.0090718.
[19] Bie D W, Li D C, Li H D, et al. Analytical study on lift performance of a bat-inspired foldable flapping wing: effect of wing arrangement[J]. Aerospace, 2022, 9(11): 653. DOI: 10.3390/aerospace9110653.
[20] Von Busse R, Hedenström A, Winter Y, et al. Kinematics and wing shape across flight speed in the bat, Leptonycteris yerbabuenae[J]. Biology Open, 2012, 1(12): 1226-1238. DOI: 10.1242/bio.20122964.
[21] Garmann D J, Visbal M R, Orkwis P D. Three-dimensional flow structure and aerodynamic loading on a revolving wing[J]. Physics of Fluids, 2013, 25(3): 034101. DOI: 10. 1063/1.4794753.
