VORTICITY FORMATION INSIDE AND NEAR CROSS-STREAMLINED SEMI-CYLINDRICAL TRENCH ON FLAT SURFACE

Authors

  • Володимир Миколайович Турик National Technical University of Ukraine "Kyiv Polytechnic Institute", Kyiv, Ukraine http://orcid.org/0000-0002-2357-4483
  • Віктор Віталійович Бабенко Institute of Hydromechanics of NAS of Ukraine, Kyiv, Ukraine
  • Володимир Анатолійович Воскобійник Institute of Hydromechanics of NAS of Ukraine, Kyiv, Ukraine
  • Андрій Володимирович Воскобійник Institute of Hydromechanics of NAS of Ukraine, Kyiv, Ukraine

DOI:

https://doi.org/10.20535/2305-9001.2015.74.47956

Keywords:

mean vorticity, voticity fluctuations, semi-cylindrical trench, hot-wire anemometer, coherent vortical structures, boundary layer

Abstract

The article are devoted to elucidation of current  macro- and microstructure inside of semi-cylindrical trench and near its in boundary layer on flat plate by means of investigation of vorticity distributions. Vorticity defines rotational components and physics of any liquid and gas motion, but in turbulent flows on working surfaces with geometric large-scale irregularities by indentations type and in currents with coherent vortical structures the vorticity takes the most important part in processes of mass, momentum and energy transfer. For better understanding of mechanism of indicated phenomenon  this paper offers some new scientific results on experimental research of vorticity and its fluctuations fields in the region of the cross-streamlined semi-cylindrical trench on a flat surface for different flow regimes according to Reynolds numbers range (by trench diameter) . The experimental investigation was carried out on open-circuit wind tunnell equipped by constant temperature anemometer with hot-wire probes, laser instrumentation, vibration and acoustic analyzer. The measurements of local time-averaged velocities and velocity fluctuations discovered that the most levels of mean vorticity take place near by the streamlined surfaces and in the angular areas of trench where boundary layer is separated and vortex structures of the shear blending layer are interacted with back wall of the trench. Zones of increased voticity fluctuation levels are disposed mainly between maximum mean vorticity regions and in area formed by interaction of coherent vortical structures of shear blending layer with quasi-stable large-scale eddy generated owing to impact interaction of blending layer with trench back wall. Results of investigation may be used for efficiency estimations of transfer processes on streamlined elements of heat exchangers, engines, ships, aircrafts etc.


Author Biographies

Володимир Миколайович Турик, National Technical University of Ukraine "Kyiv Polytechnic Institute", Kyiv

Кандидат технічних наук, доцент

Кафедра прикладної гідроаеромеханіки і механотроніки

Віктор Віталійович Бабенко, Institute of Hydromechanics of NAS of Ukraine, Kyiv

Доктор технічних наук, професор, Лауреат премій ім. О.М. Динніка та О.К. Антонова,

провідний науковий співробітник Відділу інформаційних систем в гідроаеромеханіці та екології Інституту гідромеханіки НАН України

Володимир Анатолійович Воскобійник, Institute of Hydromechanics of NAS of Ukraine, Kyiv

Доктор технічних наук, старший науковий співробітник Відділу гідробіоніки та управління примежовим шаром Інституту гідромеханіки НАН України

Андрій Володимирович Воскобійник, Institute of Hydromechanics of NAS of Ukraine, Kyiv

Кандидат технічних наук, старший науковий співробітник Відділу гідробіоніки та управління примежовим шаром Інституту гідромеханіки НАН України

References

Khalatov A.A., Heat transfer and fluid mechanics over surface indentations (dimples). A.A. Khalatov. Kyiv: National Academy of Sciences of Ukraine, Institute of Engineering Thermophysics, 2005. 64 p.

Comte P., Lesieur M., Lamballais E., Physics of Fluids, 1992, Vol. 4, No. 12, pp. 2761–2778.

Rogers M.M., Moin P., Journal of Fluid Mechanics, 1987, Vol. 176, pp. 33–66.

Shah D.A., Antonia R.A., Physics of Fluids, 1986, Vol. 29, No. 12, pp. 4016 – 4024.

Lighthill M.J., Introduction. Boundary layer theory. M.J. Lighthill. In Laminar boundary layers. Ed. L. Rosenhead. Oxford: Oxford University Press, 1963. P. 46–113.

Andreopoulos J., Agui J.H., Journal of Fluid Mechanics, 1996, Vol. 309, pp. 45–84.

Moin P., Kim J., Journal of Fluid Mechanics, 1985, Vol. 155, pp. 441–464.

Shafi H.S., Zhu Y., Antonia R.A., Physics of Fluids, 1996, Vol. 8, No. 8, pp. 2245–2247.

Rajagopalan S., Antonia R.A., Physics of Fluids, 1993, Vol. 5, No. 10, pp. 2502–2510.

Klewicki J.C., Gendrich C.P., Foss J.F., Falco R.E., Physics of Fluids, 1990, Vol. 2, No. 6, pp. 1497–1503.

Dyban E.P., Epik E.Ya., Teplomassoobmen i gidrodynamika turbulizirovannyh potokov (Heat and mass transfer and hydrodynamics of turbulent flows), Кyiv: Naukova dumka, 1985, 296 p.

Povh I.L., Aerodinamicheskij eksperiment v mashinostroenii (Aerodynamic experiment in mechanical engineering), Leningrad: Mashinostroenije, 1974, 480 p.

Balitskij F.Ya., Ivanova M.А., Sokolova Е.V., Khomjakov Е.I., Vibroakusticheskaja diagnostika zarozhdajuschihsja defektov (Vibration-acoustic diagnosis of incipient defects), Мoscow: Nauka, 1984. 120 p.

Ivovich V.A., Оnischenko V.Ya., Zaschita ot vibratsij v mashinostroenii (Protection against vibrations in engineering industry), Мoscow: Mashinostroenije, 1990, 272 p.

Alemasov V.E., Glebov G.А., Коzlov А.P., Termoanemometricheskije metody issledovanija otryvnyh techenij (Thermoanemometrical methods of stalled flows study), Kazan: Kazanskij filial AN SSSR, 1990, 178 p.

Turick V.M., Babenko V.V., Voskoboinick V.А., Voskoboinick А.V., Research Bulletin of the National Technical University of Ukraine “Kyiv Politechnic Institute”, 2008, No. 4, pp. 46–54.

Turick V.M., Babenko V.V., Voskoboinick V.А., Voskoboinick А.V., Journal of Mechanical Engineering of the National Technical University of Ukraine “Kyiv Politechnic Institute”, 2010, No. 59, pp. 110–117.

Bradshaw P. Vvedenie v turbulentnost i ee izmerenie (An Introduction to Turbulence and its Measurement), Per. s engl. Мoscow: Мir, 1974, 278 p.

Cantwell B.J., Annual Review of Fluid Mechanics, 1981, Vol. 13, pp. 457–515.

Neves J.C., Moin P., Moser R.D. Journal of Fluid Mechanics, 1994, Vol. 272, pp. 349–381.

Published

2015-10-20

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