Hostname: page-component-848d4c4894-mwx4w Total loading time: 0 Render date: 2024-06-23T14:43:33.346Z Has data issue: false hasContentIssue false

Analytical results for pitching kinematics and propulsion performance of flexible foil

Published online by Cambridge University Press:  10 January 2024

Feng Du*
Affiliation:
Beihang University, Beijing 100191, PR China
Jianghao Wu
Affiliation:
Beihang University, Beijing 100191, PR China
*
Email address for correspondence: fengdu@buaa.edu.cn

Abstract

Natural flyers and swimmers employ flexible wings or fins to propel. While the complex interaction between the foil with deformation and the surrounding non-steady fluid environment defines the propulsion performance of the propellers, elucidating the interaction mechanism through theoretical models earns much challenge. Based on elastokinetics and linear potential flow theory, this study proposes a simplified analytical model to clarify the kinematics and the propulsion performance of a flexible thin foil pitching in flow. The dynamical forces, including the inertial force of the foil and the non-steady fluid pressure, are used to determine the averaged deformation angle of the foil. Combining the averaged deformation angle and the prescribed driving pitching motion, the kinematics of the foil is resolved analytically. Based on the analytical expressions for the corresponding pitching motion, analytical relations among the physical parameters of the stiffness and the mass of the foil and the driving frequency are given to these critical conditions, including resonance of the flow–structure system, equal pitching amplitude between the flexible foil and the rigid counterpart, phase angle transition from ${\rm \pi}/2$ to $- {\rm \pi}/2$. Subsequently, the performance of the foil, including the thrust, the power and the propulsive efficiency, as a function of the flexibility of the foil are derived, together with the introduction of a bluff body type offset drag to the thrust. The formulated analytical theory, which matches nicely with previous reports, will help to interpret the effect of the flexibility and regulate the propulsive performance of the flexible foil when pitching in fluid.

Type
JFM Papers
Copyright
© The Author(s), 2024. Published by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Akkala, J.M., Eslam Panah, A. & Buchholz, J.H.J. 2015 Vortex dynamics and performance of flexible and rigid plunging airfoils. J. Fluids Struct. 54, 103121.CrossRefGoogle Scholar
Alaminos-Quesada, J. & Fernandez-Feria, R. 2019 Propulsion of a foil undergoing a flapping undulatory motion from the impulse theory in the linear potential limit. J. Fluid Mech. 883, A19.CrossRefGoogle Scholar
Alaminos-Quesada, J. & Fernandez-Feria, R. 2021 Propulsion performance of tandem flapping foils with chordwise prescribed deflection from linear potential theory. Phys. Rev. Fluids 6, 013102.CrossRefGoogle Scholar
Alben, S. 2008 Optimal flexibility of a flapping appendage in an inviscid fluid. J. Fluid Mech. 614, 355380.CrossRefGoogle Scholar
Alben, S. 2011 Flapping propulsion using a fin ray. J. Fluid Mech. 705, 149164.CrossRefGoogle Scholar
Alon Tzezana, G. & Breuer, K.S. 2019 Thrust, drag and wake structure in flapping compliant membrane wings. J. Fluid Mech. 862, 871888.CrossRefGoogle Scholar
Arora, N., Kang, C.K., Shyy, W. & Gupta, A. 2018 Analysis of passive flexion in propelling a plunging plate using a torsion spring model. J. Fluid Mech. 857, 562604.CrossRefGoogle Scholar
Chen, S., Li, H., Guo, S., Tong, M. & Ji, B. 2018 Unsteady aerodynamic model of flexible flapping wing. Aerosp. Sci. Technol. 80, 354367.CrossRefGoogle Scholar
Chin, D.D. & Lentink, D. 2016 Flapping wing aerodynamics: from insects to vertebrates. J. Exp. Biol. 219, 920932.CrossRefGoogle ScholarPubMed
Chin, Y.W., Kok, J.M., Zhu, Y.Q., Chan, W.L., Chahl, J.S., Khoo, B.C. & Lau, G.K. 2020 Efficient flapping wing drone arrests high-speed flight using post-stall soaring. Sci. Robot. 5, eaba2386.CrossRefGoogle ScholarPubMed
Dabiri, J.O. 2019 Landmarks and frontiers in biological fluid dynamics. Phys. Rev. Fluids 4, 110501.CrossRefGoogle Scholar
Demirer, E., Oshinowo, O.A., Erturk, A. & Alexeev, A. 2022 Hydrodynamic performance of oscillating elastic propulsors with tapered thickness. J. Fluid Mech. 944, A19.CrossRefGoogle Scholar
Du, F. & Wu, J. 2023 Analytical modellings for flapping wing deformation and kinematics with beam flexibility. AIAA J. 61 (2), 875889.CrossRefGoogle Scholar
Du, F., Yao, H. & Wu, J. 2023 Closed-form modellings for free and forced vibration of cantilever beam near fundamental frequency. J. Sound Vib. (submitted).Google Scholar
Eldredge, J.D. & Jones, A.R. 2019 Leading-edge vortices: mechanics and modeling. Annu. Rev. Fluid Mech. 51, 75104.CrossRefGoogle Scholar
Fernandez-Feria, R. 2016 Linearized propulsion theory of flapping airfoils revisited. Phys. Rev. Fluids 1, 084502.CrossRefGoogle Scholar
Fernandez-Feria, R. 2022 Flutter stability analysis of an elastically supported flexible foil. Application to the energy harvesting of a fully-passive flexible flapping-foil of small amplitude. J. Fluids Struct. 109, 103454.CrossRefGoogle Scholar
Fernandez-Feria, R. & Alaminos-Quesada, J. 2021 Analytical results for the propulsion performance of a flexible foil with prescribed pitching and heaving motions and passive small deflection. J. Fluid Mech. 910, A43.CrossRefGoogle Scholar
Fernandez-Feria, R. & Alaminos-Quesada, J. 2022 Energy harvesting and propulsion of pitching airfoils with passive heave and deformation. AIAA J. 60, 783797.CrossRefGoogle Scholar
Fernandez-Feria, R., Sanmiguel-Rojas, E. & Lopez-Tello, P.E. 2022 Numerical validation of simple non-stationary models for self-propelled pitching foils. Ocean Engng 260, 111973.CrossRefGoogle Scholar
Flammang, B.E. & Lauder, G.V. 2013 Pectoral fins aid in navigation of a complex environment by bluegill sunfish under sensory deprivation conditions. J. Exp. Biol. 216, 30843089.CrossRefGoogle Scholar
Floryan, D. & Rowley, C.W. 2018 Clarifying the relationship between efficiency and resonance for flexible inertial swimmers. J. Fluid Mech. 853, 271300.CrossRefGoogle Scholar
Floryan, D. & Rowley, C.W. 2020 Distributed flexibility in inertial swimmers. J. Fluid Mech. 888, A43.CrossRefGoogle Scholar
Floryan, D., Van Buren, T., Rowley, C.W. & Smits, A.J. 2017 Scaling the propulsive performance of heaving and pitching foils. J. Fluid Mech. 822, 386397.CrossRefGoogle Scholar
Floryan, D., Van Buren, T. & Smits, A.J. 2018 Efficient cruising for swimming and flying animals is dictated by fluid drag. Proc Natl Acad Sci USA 115, 81168118.CrossRefGoogle ScholarPubMed
Garrick, I.E. 1936 Propulsion of a flapping and oscillating airfoil. NACA Tech. Rep. 567.Google Scholar
Gazzola, M., Argentina, M. & Mahadevan, L. 2014 Scaling macroscopic aquatic locomotion. Nat. Phys. 10, 758761.CrossRefGoogle Scholar
Haider, N., Shahzad, A., Mumtaz Qadri, M.N. & Ali Shah, S.I. 2021 Recent progress in flapping wings for micro aerial vehicle applications. Proc. Inst. Mech. Engrs C - J. Mech. Engng Sci. 235 (2), 245264.CrossRefGoogle Scholar
Jia, K., Scofield, T., Wei, M. & Bhattacharya, S. 2021 Vorticity transfer in a leading-edge vortex due to controlled spanwise bending. Phys. Rev. Fluids 6, 024703.CrossRefGoogle Scholar
Joshi, K. & Bhattacharya, S. 2022 The unsteady force response of an accelerating flat plate with controlled spanwise bending. J. Fluid Mech. 933, A56.CrossRefGoogle Scholar
Karasek, M., Muijres, F.T., De Wagter, C., Remes, B.D.W. & de Croon, G. 2018 A tailless aerial robotic flapper reveals that flies use torque coupling in rapid banked turns. Science 361, 10891094.CrossRefGoogle ScholarPubMed
von Kármán, T. & Sears, W.R. 1938 Airfoil theory for non-uniform motion. J. Aeronaut. Sci. 5, 370.CrossRefGoogle Scholar
Kurt, M., Mivehchi, A. & Moored, K. 2021 High-efficiency can be achieved for non-uniformly flexible pitching hydrofoils via tailored collective interactions. Fluids 6, 233.CrossRefGoogle Scholar
Lauder, G.V. 2015 Fish locomotion: recent advances and new directions. Annu. Rev. Mar. Sci. 7, 521545.CrossRefGoogle ScholarPubMed
Lee, C., Kim, S. & Chu, B. 2021 A survey: flight mechanism and mechanical structure of the UAV. Intl J. Precis. Engng Manuf. 22, 719743.CrossRefGoogle Scholar
Lin, X., Wu, J. & Zhang, T. 2020 Self-directed propulsion of an unconstrained flapping swimmer at low Reynolds number: hydrodynamic behaviour and scaling laws. J. Fluid Mech. 907, R3.CrossRefGoogle Scholar
Linehan, T. & Mohseni, K. 2020 On the maintenance of an attached leading-edge vortex via model bird alula. J. Fluid Mech. 897, A17.CrossRefGoogle Scholar
Moore, M.N.J. 2014 Analytical results on the role of flexibility in flapping propulsion. J. Fluid Mech. 757, 599612.CrossRefGoogle Scholar
Moore, M.N.J. 2015 Torsional spring is the optimal flexibility arrangement for thrust production of a flapping wing. Phys. Fluids 27, 091701.CrossRefGoogle Scholar
Moore, M.N.J. 2017 A fast Chebyshev method for simulating flexible-wing propulsion. J. Comput. Phys. 345, 792817.CrossRefGoogle Scholar
Peng, Z.-R., Sun, Y., Yang, D., Xiong, Y., Wang, L. & Wang, L. 2022 Scaling laws for drag-to-thrust transition and propulsive performance in pitching flexible plates. J. Fluid Mech. 941, R2.CrossRefGoogle Scholar
Rao, SS. 2011 Mechanical Vibrations, 5th edn, pp. 721739. Pearson Education.Google Scholar
Riso, C., Riccardi, G. & Mastroddi, F. 2018 Semi-analytical unsteady aerodynamic model of a flexible thin airfoil. J. Fluids Struct. 80, 288315.CrossRefGoogle Scholar
Saadat, M., Fish, F.E., Domel, A.G., Di Santo, V., Lauder, G.V. & Haj-Hariri, H. 2017 On the rules for aquatic locomotion. Phys. Rev. Fluids 2, 083102.CrossRefGoogle Scholar
Sanmiguel-Rojas, E. & Fernandez-Feria, R. 2021 Propulsion enhancement of flexible plunging foils: comparing linear theory predictions with high-fidelity CFD results. Ocean Engng 235, 109331.CrossRefGoogle Scholar
Shahzad, A., Tian, F.B., Young, J. & Lai, J.C.S. 2018 Effects of hawkmoth-like flexibility on the aerodynamic performance of flapping wings with different shapes and aspect ratios. Phys. Fluids 30, 091902.CrossRefGoogle Scholar
Shi, G., Xiao, Q. & Zhu, Q. 2020 Effects of time-varying flexibility on the propulsion performance of a flapping foil. Phys. Fluids 32, 121904.CrossRefGoogle Scholar
Smits, A.J. 2019 Undulatory and oscillatory swimming. J. Fluid Mech. 874, P1.CrossRefGoogle Scholar
Sun, M. 2014 Insect flight dynamics: stability and control. Rev. Mod. Phys. 86, 615646.CrossRefGoogle Scholar
Taylor, G.K., Nudds, R.L. & Thomas, A.L.R. 2003 Flying and swimming animals cruise at a Strouhal number tuned for high power efficiency. Nature 425, 707711.CrossRefGoogle Scholar
Theodorsen, T. 1935 General theory of aerodynamic instability and the mechanism of flutter. Tech. Rep. 496.Google Scholar
Tytell, E.D., Hsu, C.Y., Williams, T.L., Cohen, A.H. & Fauci, L.J. 2010 Interactions between internal forces, body stiffness, and fluid environment in a neuromechanical model of lamprey swimming. Proc. Natl Acad. Sci. USA 107, 1983219837.CrossRefGoogle Scholar
Ulrich, X. & Peters, D. 2014 Loads and propulsive efficiency of a flexible airfoil performing sinusoidal deformations. J. Fluids Struct. 45, 1527.CrossRefGoogle Scholar
Van Buren, T., Floryan, D. & Smits, A.J. 2019 Scaling and performance of simultaneously heaving and pitching foils. AIAA J 57, 36663677.CrossRefGoogle Scholar
Verma, S. & Hemmati, A. 2022 Characterization of bifurcated dual vortex streets in the wake of an oscillating foil. J. Fluid Mech. 945, A7.CrossRefGoogle Scholar
Walker, W.P. & Patil, M.J. 2014 Unsteady aerodynamics of deformable thin airfoils. J. Aircraft 51, 16731680.CrossRefGoogle Scholar
Wang, T., Ren, Z., Hu, W., Li, M. & Sitti, M. 2021 Effect of body stiffness distribution on larval fish-like efficient undulatory swimming. Sci. Adv. 7, eabf7364.CrossRefGoogle ScholarPubMed
Wang, W., Huang, H. & Lu, X.-Y. 2020 Optimal chordwise stiffness distribution for self-propelled heaving flexible plates. Phys. Fluids 32, 111905.CrossRefGoogle Scholar
Wang, Y., He, X., He, G., Wang, Q., Chen, L. & Liu, X. 2022 Aerodynamic performance of the flexibility of corrugated dragonfly wings in flapping flight. Acta Mechanica Sin. 38, 322038.CrossRefGoogle Scholar
Wu, B., Shu, C., Wan, M., Wang, Y. & Chen, S. 2022 Hydrodynamic performance of an unconstrained flapping swimmer with flexible fin: a numerical study. Phys. Fluids 34, 011901.CrossRefGoogle Scholar
Wu, T.Y. 1961 Swimming of a waving plate. J. Fluid Mech. 10, 321344.CrossRefGoogle Scholar
Wu, T.Y. 2011 Fish Swimming and Bird/Insect Flight. Annu. Rev. Fluid Mech. 43, 2558.CrossRefGoogle Scholar
Yang, C.K., van der Drift, E.W.J.M. & French, P.J. 2022 Review of scaling effects on physical properties and practicalities of cantilever sensors. J. Micromech. Microeng. 32, 103002.CrossRefGoogle Scholar
Zhang, D., Huang, Q.-G., Pan, G., Yang, L.-M. & Huang, W.-X. 2021 Vortex dynamics and hydrodynamic performance enhancement mechanism in batoid fish oscillatory swimming. J. Fluid Mech. 930, A28 .CrossRefGoogle Scholar
Zhang, Y., Zhou, C. & Luo, H. 2017 Effect of mass ratio on thrust production of an elastic panel pitching or heaving near resonance. J. Fluids Struct. 74, 385400.CrossRefGoogle Scholar
Zhong, Q., Zhu, J., Fish, F.E., Kerr, S.J., Downs, A.M., Bart-smith, H. & Quinn, D.B. 2021 Tunable stiffness enables fast and efficient swimming in fish-like robots. Sci. Robot. 6, eabe4088.CrossRefGoogle ScholarPubMed
Zhu, J., White, C., Wainwright, D.K., Di Santo, V., Lauder, G.V. & Bart-Smith, H. 2019 Tuna robotics: a high-frequency experimental platform exploring the performance space of swimming fishes. Sci. Robot. 4, eaax4615.CrossRefGoogle ScholarPubMed
Zhu, X., He, G. & Zhang, X. 2014 How flexibility affects the wake symmetry properties of a self-propelled plunging foil. J. Fluid Mech. 751, 164183.CrossRefGoogle Scholar