Hydrodynamic characteristics of vortex motion inside the hemispherical dimple

Authors

DOI:

https://doi.org/10.20535/2521-1943.2018.84.144219

Keywords:

space-time characteristics, cross spectrum and correlation, coherent vortex structure, hemispherical dimple, velocity and pressure fluctuations

Abstract

Experimental researches of the features of the generation and evolution mechanism of coherent vortex structures, which are formed inside the hemispherical cavity, and space-time characteristics of the fields of velocity and pressure fluctuations that they create, both within the cavity, and in its wake, were conducted. Experiments were carried out in hydrodynamic flume on the hydraulically smooth plate with hemispherical dimple. The symmetric and asymmetric large-scale vortical systems inside a dimple are found out depending on the flow regime, and location and periodicity of their ejections are shown. The evolution of tornado-like vortices subjected to a switch mechanism that is result in appearance of low-frequency modulating transversal oscillations of vortex motion inside the hemispherical dimple. The fields of velocity, dynamic and wall pressure fluctuations by a group of hot-films, miniature piezoelectric sensors of pressure fluctuations are studied. Space-time correlations of velocity and pressure fluctuations, which generate the coherent large-scale vortex structures, the circulation flow and the vortex structure of the shear layer, which are formed inside the hemispherical dimple and ejected out into the boundary layer, are obtained. It was determined that the largest values of the coefficient of the space-time correlations of the wall pressure fluctuations observed on the aft and side walls of the hemispherical dimple, and the lowest – in its forward bottom part. It was established that the cross-correlations of the longitudinal velocity fluctuations are higher than the cross-correlations of the velocity and wall pressure fluctuations, and the cross-correlations of the dynamic and wall pressure fluctuations. On the basis of short-time spectrum and correlation analyses, the non-stationary in tame and non-uniform in space characteristics of the coherent vortical systems inside and past the open dimple have been found. Temporal periodicity of cross-correlation characteristics of the wall pressure fluctuations between two sensors, located on the fixed distance corresponds to frequencies of the shear and wake modes of resonance oscillations in the dimple. Registration of the time lag, at which the cross-correlation or anticorrelation has maximum, enables to determine the group convective velocity of the coherent vortical structures during their formation and evolution, as well as the phase of development and direction of vortex motion inside the dimple.

Author Biographies

V. Turik, Igor Sikorsky Kyiv Polytechnic Institute, Kyiv

PhD, professor

Applied hydroaeromechanics and mechatronic department

V. Voskoboinick, Institute of Hydromechanics of NAS of Ukraine, Kyiv

Відділ гідробіоніки і керування примежовим шаром,  Інститут гідромеханіки НАН України, д.т.н., провідний науковий співробітник.

A. Voskoboinick, Institute of Hydromechanics of NAS of Ukraine, Kyiv

Відділ гідробіоніки і керування примежовим шаром,  Інститут гідромеханіки НАН України, к.т.н., старший науковий співробітник

References

  1. Gortyshov, Yu.F., Popov, I.A., Olimpiev, V.V. and dr. (2009), Teplohydravlicheskaya effektivnost’ perspektivnykh sposobov intensifikacii teplootdachi v kanalakh teploobmennogo oborudovaniya, Centr innovacionnykh tekhnologii, Kazan, Russia.
  2. Kiknadze, G.I., Gachechiladze, I.A. and Gorodkov, A.Yu. (2009), “Self-organization of tornado-like jets in flows of gases and liquids and the technologies utilizing this phenomenon”, ASME 2009 Heat Transfer Summer Conference HT 2009, proc. conf. San Francisco, California, USA, HT2009-88644, pp. 1–14.
  3. Isaev, S.A., Kornev, N.V., Leontiev, A.I. and Hassel, E.(2010), “Influence of the Reynolds number and the spherical dimple depth on turbulent heat transfer and hydraulic loss in a narrow channel”, Int. J. Heat Mass Transfer, no. 53, pp. 178–197.
  4. Kovalenko, G.V., Terekhov, V.I. and Khalatov, A.A. (2010), Flow regimes in a single dimple on the channel surface, J. Appl. Mech. Techn. Physics, vol. 51, no. 6, pp. 839–848.
  5. Сharwat, A.F., Roos, J.N., Dewey, C.F. and Hiltz, J.A. (1961), “An investigation of separated flows – Part II Flow in the cavity and heat transfer”, J. Aerospace Sci., vol. 28, no.6. pp. 457–470.
  6. Voskoboinick, V.A. Voskoboinick, A.V. Voskoboinick, A.A. and Turiсk V.N. (2014), “Velocity field in median section of the semispherical dimple”, Applied Hydromechanics, vol. 16, no. 4. pp. 17–27.
  7. Voropaev, G.A., Voskoboinick, V.A., Rozumnyuk, N.V. and Voskoboinick, A.V.(2009), “Vortical flow features in a hemispherical cavity on a flat plate”, Sixth International Symposium on Turbulence and Shear Flow Phenomena, TSFP-6, 22-24 June 2009, Seoul, Korea, vol. 2, pp. 563–568.
  8. Voskoboinick, V., Voskoboinick, A. and Stepanovich, V. (2015), “Generation of vortex structures by pair oval dimples on flat surface”, Abstract European Drag Reduction and Flow Control Meeting, EDRFCM15, 22-23 March 2015, Cambridge, UK, pp. 43–44.
  9. Voskoboinick, V., Voskoboinick, V., Kornev, N. and Turnow, J. (2013), “Study of near wall coherent flow structures on dimpled surfaces using unsteady pressure measurements”, Flow Turbulence Combust, vol. 90, no. 2, pp. 86–99.
  10. Terekhov,V.I., Kalinina, S.V. and Mschvidobadze, Yu.M. (1992), “Eksperimental’noe issledovanie razvitiya techeniya v kanale s polysfericheskoi kavernoi”, Sib. fiz.-tekh. Journal, no. 1., pp. 77–85.
  11. Abo Amsha K., Craft, T.J. and Iacovides, H. (2017), “Computational modelling of the flow and heat transfer in dimpled channels”, Aeronautical journal, vol. 121, no. 1242, pp. 1066–1086.
  12. Voskoboinick, А.V., Voskoboinick, V.А., Isaev, S.А. (and dr.) (2011), Bifurkaciya vikhrevogo techeniya vnutri sfericheskoi lunki v uzkom kanale, Applied Hydromechanics, vol. 13, no. 4, pp. 3–21.
  13. Metzger, M.M. and Klewicki, J.C. (2001), “A comparative study of near-wall turbulence in high and low Reynolds number boundary layers”, Phys. Fluids, vol. 13, no. 3, pp. 692–701.
  14. Voskoboinick, V.A. and Makarenkov, A.P. (2004), “Spectral characteristics of the hydrodynamical noise in a longitudinal flow around a flexible cylinder”, Intern. J. Fluid Mech., vol. 31, no. 1. pp. 87–100.
  15. Bres, G.A. Colonius, T. (2008), “Three-dimensional instabilities in compressible flow over open cavities”, J. Fluid Mech., vol. 599, pp. 309–339.
  16. Voskoboinick, V.А. (2015), “Prostorovo-chasovi korrelacii pulsacii schvudkosti i tysku vsereduni pivsferuchnogo zaglublenniya”, Acoustic bulletin, vol. 17, no. 3, pp. 3–12.
  17. Voskoboinick, A.V., Voropaev, G.A., Voskoboinick, A.A. and Voskoboinick, V.A. (2008), “Cross correlations between velocity and pressure fluctuations in the open cavity flow”, EFMC7: 7th EUROMECH Fluid Mechanics Conf., 14-18 Sept. 2008, Manchester, UK. pp. 356.
  18. Basley, J., Pastur, L.R., Lusseyran, F. and dr. (2011), “Experimental investigation of global structures in an incompressible cavity flow using time-resolved PIV”, Exp Fluids, Vol. 50, pp. 905–918.
  19. Bendat J. and Pirsol, A. (1974), Izmerenie i analiz slychainykh processov, Mir, Moscow, Russia.
  20. Marpl-ju, S.L. (1990), Cifrovoi spectral’nyi analiz i ego prilozheniya, Mir, Moscow, Russia.

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Published

2018-12-26

How to Cite

[1]
V. Turik, V. Voskoboinick, and A. Voskoboinick, “Hydrodynamic characteristics of vortex motion inside the hemispherical dimple”, Mech. Adv. Technol., vol. 84, no. 3(84), pp. 23–32, Dec. 2018.

Issue

No. 3(84) (2018)

Section

Original study

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