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Flow visualization of supersonic laminar flow over a backward-facing step via NPLS

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Abstract

An experimental study on a supersonic laminar flow over a backward-facing step of 5 mm height was undertaken in a low-noise indraft wind tunnel. To investigate the fine structures of Ma = 3.0 and 3.8 laminar flow over a backward-facing step, nanotracer planar laser scattering was adopted for flow visualization. Flow structures, including supersonic laminar boundary layer, separation, reattachment, redeveloping turbulent boundary layer, expansion wave fan and reattachment shock, were revealed in the transient flow fields. In the Ma = 3.0 BFS (backward-facing step) flow, by measuring four typical regions, it could be found that the emergence of weak shock waves was related to the K–H (Kelvin–Helmholtz) vortex which appeared in the free shear layer and that the convergence of these waves into a reattachment shock was distinct. Based on large numbers of measurements, the structure of time-averaging flow field could be gained. Reattachment occurred at the location downstream from the step, about 7–7.5 h distance. After reattachment, the recovery boundary layer developed into turbulence quickly and its thickness increased at an angle of 4.6°. At the location of X = 14h, the redeveloping boundary layer was about ten times thicker than its original thickness, but it still had not changed into fully developed turbulence. However, in the Ma = 3.8 flow, the emergence of weak shock waves could be seen seldom, due to the decrease of expansion. The reattachment point was thought to be near X = 15h according to the averaging result. The reattachment shock was not legible, which meant the expansion and compression effects were not intensive.

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References

  1. Hall S.D., Behnia M., Fletcher C.A.J., Morrisonl G.L.: Investigation of the secondary corner vortex in a benchmark turbulent backward-facing step using cross-correlation particle imaging velocimetry. Exp. Fluids 35(2), 139–151 (2003)

    Article  Google Scholar 

  2. Shen G.X., Ma G.Y.: The investigation on the properties and structures of starting vortex flow past a back-ward facing step by WBIV technique. Exp. Fluids 21(1), 57–65 (1996)

    Article  MathSciNet  Google Scholar 

  3. Akiko, M., Masahiko, M.: Flow structure of supersonic flow past backward-facing step with perpendicular injector. AIAA-98-0939

  4. Schram C., Rambaud P., Riethmuller M.L.: Wavelet based eddy structure eduction from a backward facing step flow investigated using particle image velocimetry. Exp. Fluids 36(2), 233–245 (2004)

    Article  Google Scholar 

  5. Fadai-Ghotbi A., Manceau R., Boree J.: Revisiting URANS computations of the backward-facing step flow using second moment closures. Influence of the numerics. Flow Turbulence Combust 81, 395–414 (2008)

    Article  MATH  Google Scholar 

  6. Zhao Y.X., Yi S.H., Tian L.F., Cheng Z.Y.: Supersonic flow imaging via nanoparticles. Sci. China E: Technol. Sci. J. 52(12), 3640–3648 (2009)

    Article  MATH  Google Scholar 

  7. Zhao Y.X., Yi S.H., Tian L.F., Cheng Z.Y.: Density field measurement and approximate reconstruction of supersonic mixing layer. Chin. Sci. Bull. J. 55(19), 2004–2009 (2010)

    Article  Google Scholar 

  8. Yi S.H., He L., Zhao Y.X., Tian L.F., Cheng Z.Y.: A flow control study of a supersonic mixing layer via NPLS. Sci. China G: Phys. Mech. Astron. J. 52(12), 2001–2006 (2009)

    Article  Google Scholar 

  9. Tian L.F., Yi S.H., Zhao Y.X., He L., Cheng Z.Y.: Study of density field measurement based on NPLS technique in supersonic flow. Sci. China G: J. 52(9), 1357–1363 (2009)

    Article  Google Scholar 

  10. He L., Yi S.H., Zhao Y.X., Tian L.F., Chen Z.: Visualization of coherent structures in a supersonic flat-plate boundary layer. Chin. Sci. Bull. J. 56(6), 489–494 (2011)

    Article  Google Scholar 

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Correspondence to Z. Chen.

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Communicated by K. Kontis.

The paper was based on work that was presented at the 28th International Symposium on Shock Waves, 17–22 July 2011, Manchester, UK.

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Chen, Z., Yi, S., Tian, L. et al. Flow visualization of supersonic laminar flow over a backward-facing step via NPLS. Shock Waves 23, 299–306 (2013). https://doi.org/10.1007/s00193-012-0378-7

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  • DOI: https://doi.org/10.1007/s00193-012-0378-7

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