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Drag reduction by a flexible hairy coating

Published online by Cambridge University Press:  01 August 2022

Qian Mao ,
Jiazhen Zhao ,
Yingzheng Liu Open the ORCID record for Yingzheng Liu [Opens in a new window]  and
Hyung Jin Sung Open the ORCID record for Hyung Jin Sung [Opens in a new window]
Qian Mao
Affiliation:
Key Laboratory of Education Ministry for Power Machinery and Engineering, School of Mechanical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea
Jiazhen Zhao
Affiliation:
Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea
Yingzheng Liu
Affiliation:
Key Laboratory of Education Ministry for Power Machinery and Engineering, School of Mechanical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
Hyung Jin Sung*
Affiliation:
Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea
*
†Email address for correspondence: [email protected]
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Abstract

The hydrodynamic mechanism of drag reduction by a flexible hairy coating was explored using the penalty immersed boundary method. A two-dimensional flexible hairy coating is constituted by multiple flexible filaments. A simulation of a cylinder without a hairy coating at a Reynolds number of 100 was also performed for comparison. The results of the simulations show good agreement with the experimental data by Niu & Hu (Phys. Fluids, vol. 23, 2011, 101701), where maximum drag reduction of 22% was attained at a particular length, bending rigidity, coating density and coating angle of the hairy coating. The hydrodynamic mechanism of drag reduction was characterized in terms of the wake pattern, shape deformation and kinetic energy of the hairy coating. The effect of a non-uniform bending rigidity of the hairy coating on drag reduction was explored. A stable streamline shape of the hairy coating was found to delay the vortex formation and stabilize the recirculation zone, resulting in decreased form drag. Active flapping of the hairy coating with enhanced vortex shedding is adverse to drag reduction. A hairy coating with a stiff base and flexible trailing edge is beneficial to maintaining a stable shape.

JFM classification

Flow Control: Drag reduction
Type
JFM Papers
Information
Journal of Fluid Mechanics , Volume 946 , 10 September 2022 , A5
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Copyright
© The Author(s), 2022. Published by Cambridge University Press

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References

Abdi, R., Rezazadeh, N. & Abdi, M. 2019 Investigation of passive oscillations of flexible splitter plates attached to a circular cylinder. J. Fluid Struct. 84, 302–317.CrossRefGoogle Scholar
Assi, G.R., Bearman, P.W. & Kitney, N. 2009 Low drag solutions for suppressing vortex-induced vibration of circular cylinders. J. Fluid Struct. 25, 666–675.CrossRefGoogle Scholar
Bagheri, S., Mazzino, A. & Bottaro, A. 2012 Spontaneous symmetry breaking of a hinged flapping filament generates lift. Phys. Rev. Lett. 109, 154502.CrossRefGoogle ScholarPubMed
Banerjee, A., Gurugubelli, P.S., Kumar, N. & Jaiman, R.K. 2021 Influence of flexible fins on vortex-induced load over a circular cylinder at low Reynolds number. Phys. Fluids 33, 113602.CrossRefGoogle Scholar
Bechert, D.W., Bruse, M., Hage, W. & Meyer, R. 2000 Fluid mechanics of biological surfaces and their technological application. Naturwissenschaften 87, 157–171.CrossRefGoogle ScholarPubMed
Chen, Y., Ryu, J., Liu, Y. & Sung, H.J. 2020 Flapping dynamics of vertically clamped three-dimensional flexible flags in a Poiseuille flow. Phys. Fluids 32, 071905.CrossRefGoogle Scholar
De Langre, E. 2008 Effects of wind on plants. Annu. Rev. Fluid Mech. 40, 141–168.CrossRefGoogle Scholar
Deng, J., Mao, X. & Xie, F. 2019 Dynamics of two-dimensional flow around a circular cylinder with flexible filaments attached. Phys. Rev. E 100, 053107.CrossRefGoogle ScholarPubMed
Fage, A. & Johansen, F.C. 1928 XLII. The structure of vortex sheets. Lond. Edin. Dublin Phil. Mag. J. Sci. 5, 417–441.CrossRefGoogle Scholar
Favier, J., Dauptain, A., Basso, D. & Bottaro, A. 2009 Passive separation control using a self-adaptive hairy coating. J. Fluid Mech. 627, 451–483.CrossRefGoogle Scholar
García-Baena, C., Jiménez-González, J.I., Gutiérrez-Montes, C. & Martínez-Bazán, C. 2021 Numerical analysis of the flow-induced vibrations in the laminar wake behind a blunt body with rear flexible cavities. J. Fluid Struct. 100, 103194.CrossRefGoogle Scholar
Goldstein, D., Handler, R. & Sirovich, L. 1993 Modeling a no-slip flow boundary with an external force field. J. Comput. Phys. 105, 354–366.CrossRefGoogle Scholar
Glowinski, R., Pan, T.W., Hesla, T.I. & Joseph, D.D. 1999 A distributed Lagrange multiplier/fictitious domain method for particulate flows. Intl J. Multiphase Flow 25, 755–794.CrossRefGoogle Scholar
Huang, W.X., Shin, S.J. & Sung, H.J. 2007 Simulation of flexible filaments in a uniform flow by the immersed boundary method. J. Comput. Phys. 226, 2206–2228.CrossRefGoogle Scholar
Huang, W.X. & Sung, H.J. 2010 Three-dimensional simulation of a flapping flag in a uniform flow. J. Fluid Mech. 653, 301–336.CrossRefGoogle Scholar
Hwang, J., Lee, J., Sung, H.J. & Zaki, T.A. 2016 Inner–outer interactions of large-scale structures in turbulent channel flow. J. Fluid Mech. 790, 128–157.CrossRefGoogle Scholar
Hwang, J. & Sung, H.J. 2018 Wall-attached structures of velocity fluctuations in a turbulent boundary layer. J. Fluid Mech. 856, 958–983.CrossRefGoogle Scholar
Koehl, M.A.R. 1984 How do benthic organisms withstand moving water? Am. Zool. 24, 57–70.CrossRefGoogle Scholar
Kunze, S. & Brücker, C. 2012 Control of vortex shedding on a circular cylinder using self-adaptive hairy-flaps. C. R. Méc. 340, 41–56.CrossRefGoogle Scholar
Lee, J., Lee, J.H., Choi, J.-I. & Sung, H.J. 2014 Spatial organization of large- and very-large-scale motions in a turbulent channel flow. J. Fluid Mech. 749, 818–840.CrossRefGoogle Scholar
Lee, J. & You, D. 2013 Study of vortex-shedding-induced vibration of a flexible splitter plate behind a cylinder. Phys. Fluids 25, 110811.CrossRefGoogle Scholar
Mao, Q.A., Zhao, J., Liu, Y. & Sung, H.J. 2021 a Drag reduction by a flexible afterbody. Phys. Fluids 33, 122009.CrossRefGoogle Scholar
Mao, Q.A., Wang, P., He, C. & Liu, Y. 2021 b Unsteady flow structures behind a shark denticle replica on the wall: Time-resolved particle image velocimetry measurements. Phys. Fluids 33, 075109.CrossRefGoogle Scholar
Niu, J. & Hu, D.L. 2011 Drag reduction of a hairy disk. Phys. Fluids 23, 101701.CrossRefGoogle Scholar
Park, T.S. & Sung, H.J. 2001 Development of a near-wall turbulence model and application to jet impinging heat transfer. Intl J. Heat Fluid Flow 22 (10), 18.CrossRefGoogle Scholar
Pastoor, M., Henning, L., Noack, B.R., King, R. & Tadmor, G. 2008 Feedback shear layer control for bluff body drag reduction. J. Fluid Mech. 608, 161–196.CrossRefGoogle Scholar
Peskin, C.S. 2002 The immersed boundary method. Acta Numerica 11, 479–517.CrossRefGoogle Scholar
Roshko, A. 1955 On the wake and drag of bluff bodies. J. Aeronaut. Sci. 22, 124–132.CrossRefGoogle Scholar
Shen, P., Lin, L., Wei, Y., Dou, H. & Tu, C. 2019 Vortex shedding characteristics around a circular cylinder with flexible film. Eur. J. Mech. (B/Fluid) 77, 201–210.CrossRefGoogle Scholar
Shin, S.J., Huang, W.X. & Sung, H.J. 2008 Assessment of regularized delta functions and feedback forcing schemes for an immersed boundary method. Intl J. Numer. Meth. Fluids 58, 263–286.CrossRefGoogle Scholar
Shukla, S., Govardhan, R.N. & Arakeri, J.H. 2013 Dynamics of a flexible splitter plate in the wake of a circular cylinder. J. Fluid Struct. 41, 127–134.CrossRefGoogle Scholar
Teksin, S. & Yayla, S. 2016 Effects of flexible splitter plate in the wake of a cylindrical body. J. Appl. Fluid Mech. 9, 3053–3059.Google Scholar
Williamson, C.H. & Govardhan, R. 2004 Vortex-induced vibrations. Annu. Rev. Fluid Mech. 36, 413–455.CrossRefGoogle Scholar
Wu, J., Qiu, Y.L., Shu, C. & Zhao, N. 2014 Flow control of a circular cylinder by using an attached flexible filament. Phys. Fluids 26, 103601.CrossRefGoogle Scholar
Wu, J., Wu, J. & Zhan, J. 2016 Characteristics of flow over a circular cylinder with two attached filaments. J. Fluid Struct. 66, 269–281.CrossRefGoogle Scholar
Xu, S. & Wang, Z.J. 2006 An immersed interface method for simulating the interaction of a fluid with moving boundaries. J. Comput. Phys. 216, 454–493.CrossRefGoogle Scholar
Yuan, H.Z., Niu, X.D., Shu, S., Li, M. & Yamaguchi, H. 2014 A momentum exchange-based immersed boundary-lattice Boltzmann method for simulating a flexible filament in an incompressible flow. Comput. Maths Applics. 67, 1039–1056.CrossRefGoogle Scholar