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On streamwise vortical structures in the near-field of axisymmetric shear layers

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Abstract

Pairs of counter-rotating streamwise vortical structures have been observed using the LIF (Laser Induced Fluorescence) flow visualization technique by means of regular, video and high-speed photography in the near-field of an axisymmetric water jet. The temporal evolution of these structures at fixedx/d=1.0, 2.0, 4.0, and 6.0 in planes perpendicular to the flow direction for Reynolds numbersRe=cd/v=6000 has been the focus of attention in this investigation (d = nozzle diameter,c = mean exit velocity). These streamwise vortical structures also appear when the formation of Taylor-Görtler vortices in the nozzle is suppressed. So far basic questions pertaining to the generation and development of these secondary structures remain unanswered. Understanding of instability and interaction mechanisms can be gained by the analysis of these structures. These also contribute to entrainment and mixing due to their dynamics and large interfacial area.

Sommario

Coppie di strutture tubolari controrotanti sono state osservate usando la tecnica di visualizzazione del flusso LIF (Laser Induced Fluorescence), per mezzo di una telecamera ad alta e bassa velocità, nel campo vicino ad un getto d'acqua assialsimmetrico. Lo studio dell'evoluzione temporale di queste strutture, fissatox/d=1.0, 2.0, 4.0 e 6.0 in piani perpendicolari alla direzione del flusso ed in sezioni longitudinali perx/d=0÷6.0, per numeri di Reynolds Re=cd/v=6000, è stato il punto principale della presente indagine. Queste strutture vorticose appaiono persino quando la formazione dei vortici di Taylor-Görtler è soppressa attivamente e passivamente. Si osserva che rimangono senza risposta questioni basilari concernenti la generazione e lo sviluppo di queste strutture secondarie. Attraverso l'analisi di queste strutture è possibile far progressi nella conoscenza dell'instabilità e dei meccanismi d'interazione. Inoltre, tali strutture contribuiscono all'intrappolamento ed al mescolamento dovuti alla loro dinamica ed alla larga area interfacciale.

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References

  1. Yule, A.J. ‘Large-scale structure in the mixing layer of a round jet’,J. Fluid Mech. 89 (1978) 413–432.

    Google Scholar 

  2. Bernal, L.P., ‘The coherent structure in turbulent mixing layers, II: Secondary streamwise vortex structure’. Ph.D Thesis. Caltech, (1981).

  3. Jimenez, J., Cogollos, M. and Bernal, L.P., ‘A perspective view of the plane mixing layer’,J. Fluid Mech. 152 (1985) 125–143.

    Google Scholar 

  4. Lasheras, A., Cho and Maxworthy, ‘Streamwise vorticity in a plane free shear layer’,J. Fluid Mech. 172 (1986) 231–258.

    Google Scholar 

  5. Lin, S.J. and Corcos, G.M., ‘The mixing layer: deterministic model of a turbulent flow. Part 3. The effect of plane strain on the dynamics of streamwise vortices’,J. Fluid Mech. 141 (1984) 139–178.

    Google Scholar 

  6. Widnall, S.E. and Sullivan, J.P., ‘On the stability of vortex rings’,Proc. Roy. Soc. A332 (1973) 335–353.

    Google Scholar 

  7. Martin, J.E. and Meiburg, E., ‘Numerical investigation of three-dimensionally evolving jets’,J. Fluid Mech. 230 (1991) 271–318.

    Google Scholar 

  8. Verzicco, R. and Orlandi, P., ‘Direct simulations of the transitional regime of a circular jet’,Physics of Fluids 6(2) (1994) 751–759.

    Google Scholar 

  9. Liepmann, D. and Gharib, M., ‘The role of streamwise vorticity in the near-field entrainment of round jets’,J. Fluid Mech. 245 (1992) 643–668.

    Google Scholar 

  10. Brancher, P., Chomaz, J.M. and Huerre, P., ‘Direct numerical simulations of round jets: vortex induction and side jets’. 1993 Euromech 305 Dynamics and geometry of vortical structures. Cortona, Italy. June 28 — July 2.

  11. Monkewitz, P. and Pfizenmaier, E., ‘Mixing by “side jets” in strongly forced and self-excited round jets’,Phys. Fluids A3(5), May 1991.

  12. Agui, J.C. and Hesselink, L., ‘Flow visualisation and numerical analysis of a coflowing jet: a three-dimensional approach’,J. Fluid Mech. 191 (1988) 19–45.

    Google Scholar 

  13. Becker, H.A. and Massaro, T.A., ‘Vortex evolution in a round jet’,J. Fluid Mech. 31 (1968) 435–448.

    Google Scholar 

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Suprayan, R., Fiedler, H.E. On streamwise vortical structures in the near-field of axisymmetric shear layers. Meccanica 29, 403–410 (1994). https://doi.org/10.1007/BF00987575

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  • DOI: https://doi.org/10.1007/BF00987575

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