DESIGNING AND DETAILING OF BUILDING SYSTEMS. MECHANICS IN CIVIL ENGINEERING

ANALYSIS OF CHANGES IN THE PROFILE OF TANGENTIAL VELOCITIES OF THE FLOW SHAPED UP BY THE LOCAL SWIRLER

Vestnik MGSU 5/2012
  • Zuykov Andrey L'vovich - Moscow State University of Civil Engineering (MGSU) Doctor of Technical Sciences, Professor, Department of Hydraulics and Water Resources, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoye shosse, Moscow, 129337, Russian Federation; +7 (495)287-49-14, ext. 14-18; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 23 - 28

The profile of tangential velocities of a longitudinal turbulent rotational flow (Fig. 1) at the inlet of a cylindrical tube with a local swirler is characterized by radial zoning. The fluid rotation pattern transforms from a forced vortex in the center of the flow alongside the tube axis into a free vortex at the periphery. The boundary between the zones of forced and free rotation represents the radius , where tangential velocity reaches its maximum value . Analysis of the profile approximation in Fig. 1 through the application of the Burgers-Batchelor (1) free and forced vortex methodology makes it possible to identify the following regularities. It is proven that the distribution of the tangential velocity and the change in the number of swirls are described by functions (8) and (9), where 0 and 0 stand for the tangential velocity and the number of swirls at the tube inlet immediately after the local swirler, where is the radius of the tube, is the radial coordinate, h is a constant value equal to 1.256. The author has identified that functions (8) and (9) represented in Fig. 2 depend on parameter2 2 8 = Re , where is the axial coordinate, Reis the turbulent analogue of the Reynolds number, calculated in accordance with formula (12). The author demonstrates that if > 0.0995 Rethe tangential velocity is not maximal, the fluid rotates as a rigid body, and its rotation pattern corresponds to the stage of rotation degeneration, in which the 0 ratio falls below 0.4306. The analysis demonstrates that the result of multiplying the maximal velocity at radius in any section of the tube remains constant and it is equal to 0.7152 0 .

DOI: 10.22227/1997-0935.2012.5.23 - 28

References
  1. Trinh C.M. Turbulence Modeling of Confined Swirling Flows. Roskilde, Riso National Laboratory, 1998, Riso-R-647(EN).
  2. Zuykov A.L. Approksimiruyushchie profili tsirkulyatsionnykh kharakteristik zakruchennogo techeniya [Approximating Profiles of Circulation Charactertistics of a Swirling Flow]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2011, no. 5, pp. 185—190.
  3. Zuykov A.L. Kriterii dinamicheskogo podobiya tsirkulyatsionnykh techeniy [Criteria of Dynamic Similarity of Circulating Flows]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2010, no. 3, pp. 106—112.
  4. Zuykov A.L. Radial’no-prodol’noe raspredelenie azimutal’nykh skorostey v techenii za lokal’nym zavikhritelem [Radial-Longitudinal Distribution of Azimuthal Velocity of the Flow behind the Local Swirler]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2011, no. 2, pр. 119—123.
  5. Zuykov A.L., Volshanik V.V. Analiticheskoe issledovanie struktury potoka vyazkoy neszhimaemoy zhidkosti v tsilindricheskoy trube [Analytical Study of the Structure of the Flow of Viscous Incompressible Fluid in a Cylindrical Tube]. Moscow, Moscow State University of Civil Engineering, 2001.
  6. Spravochnik po gidravlicheskim raschetam [Handbook of Hydraulic Calculations]. Edited by Kiselyov P.G. Moscow, Energiya Publ., 1972.

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Transformation model of modified Couette vortex along the channel

Vestnik MGSU 7/2014
  • Zuykov Andrey L'vovich - Moscow State University of Civil Engineering (MGSU) Doctor of Technical Sciences, Professor, Department of Hydraulics and Water Resources, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoye shosse, Moscow, 129337, Russian Federation; +7 (495)287-49-14, ext. 14-18; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 147-155

The article is a further research of a circular-longitudinal flow created in a cylindrical pipe by a continuous swirler called Couette vortex, which the author started to study in his previous works. The key question is how Couette modified vortex is transformed along the channel (pipe). The author regards variation of azimuthal velocities (
u) and the Heeger-Baer’s swirl number (
Sn) in turbulent irregular circular-longitudinal flow, which is described by the model of modified Couette vortex along the cylindrical channel. It is confirmed that the model of the modified Couette vortex and free-forced Burgers - Batchelor vortex show almost similar results in calculations and both vortex models can be equally used in engineering practice in calculations and the analysis of circulating and longitudinal flow operating modes (vortex flows).

DOI: 10.22227/1997-0935.2014.7.147-155

References
  1. Zuykov A.L. Modifitsirovannyy vikhr' Kuetta [Modified Couette Vortex]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2010, no. 4, pp. 66—71.
  2. Chinh M.T. Turbulence Modeling of Confined Swirling Flows. Roskilde. Riso National Laboratory, 1998, Riso-R-647(EN), ð. 32.
  3. Fernandez-Feria R., Fernandez de la Mora J.,Barrero A. Solution Breakdown in a Family of Self-similar Nearly Inviscid Oxisymmetric Vortices. Journal of Fluid Mechanics. 1995, no. 305, ðð. 77—91.
  4. Delery J.M. Aspects of Vortex Breakdown. Progr. Aerospace Sci. 1994, vol. 30, no. 1, ð. 59. DOI: http://dx.doi.org/10.1016/0376-0421(94)90002-7.
  5. Kitoh O. Experimental Study of Turbulent Swirling Flow in a Straight Pipe. Journal of Fluid Mechanics. 1991, vol. 225, pp. 445—479. DOI: http://dx.doi.org/10.1017/S0022112091002124 (About DOI).
  6. Saburov E.N., Karpov S.V., Ostashev S.I. Teploobmen i aerodinamika zakruchennogo potoka v tsiklonnykh ustroystvakh [Heat Transfer and Aerodynamics of Swirling Flow in Cyclone Devices]. Leningrad, Leningrad State University Publ., 1989, 176 p.
  7. Vatistas G.H., Lin S., Kwok C.K. An Analytical and Experimental Study on the Coresize and Pressure Drop across a Vortex Chamber. AIAA Paper, 17th Fluid Dynamics, Plasma Dynamics, and Lasers Conference. 1984, no. 84—1548, 24 p.
  8. Gupta A.K., Lilley D., Syred N. Swirl Flows. London, Abacus Press, 1984, 475 p. DOI: http://dx.doi.org/10.1016/0010-2180(86)90133-1.
  9. Escudier M., Bornstein J., Zehnder N. Observations and LDA Measurements of Confined Turbulent Vortex Flow. Journal of Fluid Mechanics. 1980, vol. 98, no. 1, ðð. 49—64. DOI: http://dx.doi.org/10.1017/S0022112080000031.
  10. Zuykov A.L. Radial'no-prodol'noe raspredelenie azimutal'nykh skorostey v techenii za lokal'nym zavikhritelem [Radially-longitudinal Distribution of Azimuthal Velocities in the Flow Behind Local Swirler]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2011, no. 2, pð. 119—123.
  11. Zuykov A.L. Approksimiruyushchie profili tsirkulyatsionnykh kharakteristik zakruchennogo techeniya [Approximating Profiles of the Circulation Characteristics of a Swirling Flow]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2011, no. 5, pp. 185—190.
  12. Zuykov A.L. Analiz izmeneniya profilya tangentsial'nykh skorostey v techenii za lokal'nym zavikhritelem [Analysis of Changes in the Profile of the Tangential Velocities in the Flow Behind Local Swirler]. Vestnik MGSU [Proceedings of the Moscow State University of Civil Engineering]. 2012, no. 5, pp. 23—28.
  13. Burgers J.M. A Mathematical Model Illustrating Theory of Turbulence. Advances in Applied Mechanics. 1948, no. 1, ðp. 171—199.
  14. Batchelor G.K. An Introduction to Fluid Dynamics. Cambridge University Press. New Ed. 2002, 631 p.
  15. Zuykov A.L. Gidrodinamika tsirkulyatsionnykh techeniy [Hydrodynamics of Circulating Currents]. Moscow. Association of Building Institutions of Higher Education Publ., 2010, 216 p.
  16. Kiselyov P.G., editor. Spravochnik po gidravlicheskim raschetam [Handbook of Hydraulic Calculations]. 4th Edition. Moscow. Energiya Publ., 1972, 312 p.
  17. Zuykov A.L. Kriterii dinamicheskogo podobiya tsirkulyatsionnykh techeniy [Criteria of Dynamic Similarity of Circulating Flow]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2010, no. 3, ðp. 106—112.

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Hydraulic modeling of the flows with counter-rotating coaxial layers

Vestnik MGSU 6/2014
  • Zuykov Andrey L'vovich - Moscow State University of Civil Engineering (MGSU) Doctor of Technical Sciences, Professor, Department of Hydraulics and Water Resources, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoye shosse, Moscow, 129337, Russian Federation; +7 (495)287-49-14, ext. 14-18; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 114-125

The article is devoted to hydraulic modeling of flows with counter-rotating coaxial layers. Dynamic similarity criteria of such flows were found by the inspection analysis of the Reynolds equations. It was found that the hydrodynamic similarity criteria for physical modeling of unsteady turbulent circular-longitudinal flows with counter-rotating coaxial layers of viscous incompressible fluid are: Strouhal number - the ratio of forces of local and convective inertia, Rossby number characterizes the ratio of the azimuthal and axial velocity, Froude number - the ratio of forces of convective inertia to the forces of gravity, Euler number - the ratio of pressure forces to the convective forces of inertia, Weber number - the ratio of the convective inertia forces to surface tension forces, Reynolds number - the ratio of the convective inertia forces to the forces of molecular viscosity, Karman number - the ratio of dispersion velocity vector of fluid particles to the flow velocity. The limit value of the Reynolds number was found at the lower boundary conditions of automodel zone of such flow. It is shown that Weber and Rossby criteria for physical modeling of such flows are not determinative. It was found out that turbulent circular-longitudinal flow with counter-rotating coaxial layers are not modeled using Karman criterion. In this connection, there is a need to conduct experimental methodological research of turbulent flows with counter-rotating coaxial layers on stands equipped means of three-dimensional laser Doppler anemometry. Integral criteria of dynamic similarity of circular-longitudinal flows was considered - Heeger-Baer number (swirl number) and Abramovich number, characterizing the ratio of the angular momentum and momentum of such flows. In comparison with the swirl number, Heeger-Baer number is more preferable. Abramovich number is equal to the geometric characteristics of the local swirler as similarity criterion of circular-longitudinal incompressible fluid flows, including counter-rotating coaxial layers. Basing on summation of the angular momenta of coaxial counter-rotating layers, integral criterion of dynamic similarity of these flows was obtained. A common system of basic hydrodynamic similarity criteria was defined for physical modeling of unsteady turbulent circular-longitudinal viscous liquid flows with counter-rotating coaxial layers. For this kind of flow criterial equation was compiled.

DOI: 10.22227/1997-0935.2014.6.114-125

References
  1. Sviridenkov A.A., Tret'yakov V.V., Yagodkin V.I. Ob effektivnosti smesheniya koaksial'nykh potokov, zakruchennykh v protivopolozhnye storony [On the Effectiveness of Mixing Coaxial Flows Twisted in Opposite Directions]. Inzhenerno-fizicheskiy zhurnal [Journal of Engineering Physics]. Minsk, Belarus, 1981, vol. 41, no. 3, pp. 407—413.
  2. Sviridenkov A.A., Tret'yakov V.V. Eksperimental'noe issledovanie smesheniya turbulentnykh protivopolozhno zakruchennykh struy na nachal'nom uchastke v kol'tsevom kanale [Experimental Study of Turbulent Mixing of Oppositely Swirled Jets in the Initial Section in Annular Channel]. Inzhenerno-fizicheskiy zhurnal [Journal of Engineering Physics]. Minsk, Belarus, 1983, vol. 44, no. 2, pp. 205—210.
  3. Vu B.T., Gouldin F.C. Flow Measurements in a Model Swirl Combustor. AIAA Journal. 1982, vol. 20, no. 5, pp. 642—651. DOI: http://dx.doi.org/10.2514/3.51122.
  4. Mattingly J.D., Oates G.S. An Investigation of the Mixing of Co-annular Swirling Flows. AIAA paper. 1985, no. 85-0186, 15 p.
  5. Chen Y.S. Numerical Methods for Three-Dimensional Incompressible Flow Using Nonorthogonal Body-Fitter Coordinate Systems. AIAA paper. 1986, no. 86—1654, 9 р.
  6. Chao Y.C. Recirculation Structure of the Co-annular Swirling Jets in a Combustor. AIAA Journal. 1988, vol. 26, no. 5, pp. 623—625. DOI: http://dx.doi.org/10.2514/3.9944.
  7. Akhmetov V.K., Shkadov V.Ya. Chislennoe modelirovanie vyazkikh vikhrevykh techeniy dlya tekhnicheskikh prilozheniy [Numerical Simulation of Viscous Vortex Flows for Technical Applications]. Moscow, ASV Publ., 2009, 176 p.
  8. Akhmetov V.K., Volshanik V.V., Zuykov A.L., Orekhov G.V. Modelirovanie i raschet kontrvikhrevykh techeniy [Modeling and Calculation of Counter-Vortex Flows]. Ed. By A.L. Zuykov. Мoscow, ASV Publ., 2012, 252 p.
  9. Gupta A.K., Lilley D., Syred N. Swirl Flows. London, Abacus Press, 1984, 475 p.
  10. Zuykov A.L. Kriterii dinamicheskogo podobiya tsirkulyatsionnykh techeniy [Criteria Dynamic Similarity of Circulating Flows]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2010, no. 3, рp. 106—112.
  11. Zuykov A.L. Gidrodinamika tsirkulyatsionnykh techeniy [Hydrodynamics of Circulating Currents]. Moscow, ASV Publ., 2010, 216 p.
  12. Wilcox D.C. Turbulence Modeling for CFD. DCW Industries, 2nd ed.1998, 537 p.
  13. Volshanik V.V., Zuykov A.L., Mordasov A.P. Zakruchennye potoki v gidrotekhnicheskikh sooruzheniyakh [Swirling Flows in Hydraulic Structures]. Мoscow, Energoatomizdat Publ., 1990, 280 p.
  14. Kiselyov P.G., editor. Spravochnik po gidravlicheskim raschetam [Handbook of Hydraulic Calculations]. 4th Ed., revised and expanded. Moscow. Energiya Publ., 1972, 382 р.
  15. Batchelor G.K. An Introduction to Fluid Dynamics. Cambridge University Press, New ed., 2002, 631 p.
  16. Zuykov A.L. Povyshenie turbulentnosti tsirkulyatsionnykh techeniy [Increased Turbulence of Circulating Currents]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2009, no. 2, pp. 80—95.
  17. Orekhov G.V. Modelirovanie kontrvikhrevykh sistem. Masshtabnaya seriya issledovaniy [Modeling Counter Vortex Systems. Large-scale Series of Studies]. Internet-zhurnal «Naukovedenie» [Internet Journal "Science Studies"]. 2013, no. 4-54TBH413, 11 p.
  18. Knauss J., Rotterdam. A.A., editors. Swirling Flow Problems at Intakes. Balkema Publ., 1987, 165 p.
  19. Kapustin S.A., Orekhov G.V., Churin P.S. Eksperimental'nye model'nye issledovaniya kontrvikhrevykh techeniy [Experimental Studies of the Counter Vortex Currents’ Models]. Internet-zhurnal «Naukovedenie» [Internet Journal "Science Studies"]. 2013, no. 4—53TBH413, 16 p.

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