Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-16T23:24:28.315Z Has data issue: false hasContentIssue false
  • English
  • Français

Significance of the strain-dominated region around a vortex on induced aerodynamic loads

Published online by Cambridge University Press:  14 May 2021

Karthik Menon Open the ORCID record for Karthik Menon [Opens in a new window]  and
Rajat Mittal Open the ORCID record for Rajat Mittal [Opens in a new window]
Karthik Menon*
Affiliation:
Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD21218, USA
Rajat Mittal*
Affiliation:
Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD21218, USA
*
†Email addresses for correspondence: [email protected], [email protected]
†Email addresses for correspondence: [email protected], [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

The ability of vortices to induce aerodynamic loads on proximal surfaces plays a significant role in a wide variety of flows. However, most studies of vortex-induced effects primarily focus on analysing the influence of the rotation-dominated cores of vortices. In this work, we show that not only are vortices in viscous flows surrounded by strain-dominated regions, but these regions are dynamically important and can sometimes even dictate the induced aerodynamic loads. We demonstrate this for a pitching airfoil, which exhibits dynamic stall and generates several force-inducing vortices. Using a data-driven force partitioning method (FPM), we quantify the influence of vortices as well as vortex-associated strain to show that our current understanding of vortex-dominated phenomena, such as dynamic stall, is incomplete without considering the substantial effect of strain-dominated regions that are associated with vortices.

JFM classification

Vortex Flows: Vortex shedding Vortex Flows: Vortex dynamics Wakes/Jets: Separated flows
Type
JFM Rapids
Information
Journal of Fluid Mechanics , Volume 918 , 10 July 2021 , R3
Check for updates
Copyright
© The Author(s), 2021. 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

REFERENCES

Acheson, D.J. 1990 Elementary Fluid Dynamics. Oxford University Press.Google Scholar
Batchelor, G.K. 1967 An Introduction to Fluid Dynamics. Cambridge University Press.Google Scholar
Carr, L.W. 1988 Progress in analysis and prediction of dynamic stall. J. Aircraft 25 (1), 6–17.CrossRefGoogle Scholar
Chen, K.K., Colonius, T. & Taira, K. 2010 The leading-edge vortex and quasisteady vortex shedding on an accelerating plate. Phys. Fluids 22 (3), 1–11.CrossRefGoogle Scholar
Dickinson, M.H. & Götz, K.G. 1993 Unsteady aerodynamic performance of model wings at low Reynolds numbers. J. Expl Biol. 174 (1), 45–64.CrossRefGoogle Scholar
Eldredge, J.D. & Jones, A.R. 2019 Leading-edge vortices: mechanics and modeling. Annu. Rev. Fluid Mech. 51, 75–104.CrossRefGoogle Scholar
Ellington, C.P., van den Berg, C., Willmott, A.P. & Thomas, A.L.R. 1996 Leading-edge vortices in insect flight. Nature 384 (6610), 626–630.CrossRefGoogle Scholar
Ester, M., Kriegel, H., Sander, J. & Xu, X. 1996 A density-based algorithm for discovering clusters in large spatial databases with noise. In Proceedings of the 2nd International Conference on Knowledge Discovery and Data Mining, pp. 226–231. AAAI.Google Scholar
Gharali, K. & Johnson, D.A. 2013 Dynamic stall simulation of a pitching airfoil under unsteady freestream velocity. J. Fluids Struct. 42, 228–244.CrossRefGoogle Scholar
Haller, G. 2015 Lagrangian coherent structures. Annu. Rev. Fluid Mech. 47 (1), 137–162.CrossRefGoogle Scholar
Hunt, J.C.R., Wray, A.A. & Moin, P. 1988 Eddies, stream, and convergence zones in turbulent flows. Center for Turbulence Research Report CTR-S88, pp. 193–208.Google Scholar
Jeong, J. & Hussain, F. 1995 On the identification of a vortex. J. Fluid Mech. 285, 69–94.CrossRefGoogle Scholar
Lamb, H. 1993 Hydrodynamics. Cambridge University Press.Google Scholar
Li, J., Zhao, X. & Graham, M. 2020 Vortex force maps for three-dimensional unsteady flows with application to a delta wing. J. Fluid Mech. 900, A36.CrossRefGoogle Scholar
Menon, K. & Mittal, R. 2019 Flow physics and dynamics of flow-induced pitch oscillations of an airfoil. J. Fluid Mech. 877, 582–613.CrossRefGoogle Scholar
Menon, K. & Mittal, R. 2020 a Aerodynamic characteristics of canonical airfoils at low Reynolds numbers. AIAA J. 58 (2), 977–980.CrossRefGoogle Scholar
Menon, K. & Mittal, R. 2020 b On the initiation and sustenance of flow-induced vibration of cylinders: insights from force partitioning. J. Fluid Mech. 907, A37.CrossRefGoogle Scholar
Menon, K. & Mittal, R. 2020 c Quantitative analysis of the kinematics and induced aerodynamic loading of individual vortices in vortex-dominated flows: a computation and data-driven approach. arXiv:2011.04632.Google Scholar
Mittal, R., Dong, H., Bozkurttas, M., Najjar, F.M., Vargas, A. & von Loebbecke, A. 2008 A versatile sharp interface immersed boundary method for incompressible flows with complex boundaries. J. Comput. Phys. 227 (10), 4825–4852.CrossRefGoogle ScholarPubMed
Mulleners, K. & Raffel, M. 2013 Dynamic stall development. Exp. Fluids 54, 1469.CrossRefGoogle Scholar
Onoue, K. & Breuer, K.S. 2016 Vortex formation and shedding from a cyber-physical pitching plate. J. Fluid Mech. 793, 229–247.CrossRefGoogle Scholar
Pitt Ford, C.W. & Babinsky, H. 2013 Lift and the leading-edge vortex. J. Fluid Mech. 720, 280–313.CrossRefGoogle Scholar
Sane, S.P. 2003 The aerodynamics of insect flight. J. Expl Biol. 206 (23), 4191–4208.CrossRefGoogle ScholarPubMed
Seo, J.H. & Mittal, R. 2011 A sharp-interface immersed boundary method with improved mass conservation and reduced spurious pressure oscillations. J. Comput. Phys. 230 (19), 7347–7363.CrossRefGoogle ScholarPubMed
Shyy, W. & Liu, H. 2007 Flapping wings and aerodynamic lift: the role of leading-edge vortices. AIAA J. 45 (12), 2817–2819.CrossRefGoogle Scholar
Triantafyllou, M.S., Triantafyllou, G.S. & Yue, D.K.P. 2000 Hydrodynamics of fishlike swimming. Annu. Rev. Fluid Mech. 32 (1), 33–53.CrossRefGoogle Scholar
Wang, C. & Eldredge, J.D. 2013 Low-order phenomenological modeling of leading-edge vortex formation. Theor. Comput. Fluid Dyn. 27 (5), 577–598.CrossRefGoogle Scholar
Xia, X. & Mohseni, K. 2013 Lift evaluation of a two-dimensional pitching flat plate. Phys. Fluids 25 (9), 91901.CrossRefGoogle Scholar
Zhang, C., Hedrick, T.L. & Mittal, R. 2015 Centripetal acceleration reaction: an effective and robust mechanism for flapping flight in insects. PLoS ONE 10 (8), 1–16.Google ScholarPubMed