Skip to main content
SpringerLink
Log in

Schlieren techniques for the visualization of an expansion fan/shock wave interaction

  • Regular Paper
  • Published:
Journal of Visualization Aims and scope Submit manuscript

Abstract

The interaction between an expansion fan and a shock wave and the resulting flow field are of importance both from a research and an applied perspective. Interesting flow phenomena arise from this interaction which are significant in supersonic engine inlet design and aircraft store carriage and release. This paper focuses on the use of various schlieren techniques to experimentally visualize an expansion fan/shock wave interaction. The expansion fan was generated by a single wedge and the shock wave by another, at various Mach numbers. Three cut-off techniques were investigated: a knife edge, a tri-colour mask and a band lattice mask. Each of these cut-offs was placed in three orientations, parallel to the freestream flow direction, at −45° and perpendicular to the flow, to determine the effects of the directional sensitivity of the system. The different cut-off techniques and respective orientations were evaluated on the efficacy of visualizing flow features of interest, namely the expansion fan and deflection thereof, shock curvature and sliplines formed as a result of the interaction. Each technique produced visualization with varying degrees of clarity. There was a dependence on the system’s directional sensitivity when visualizing both the expansion fan deflection and the shock curvature. The visualization of the expansion fan/shock wave interaction using the band lattice mask parallel to the freestream was particularly effective as it showed all the features of interest (excepting the sliplines as these formed a region of varying entropy rather than occurring as discrete lines). Consequently, it was shown that schlieren is a valuable tool in the experimental visualization of an expansion fan/shock wave interaction.

Graphical Abstract

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11

Similar content being viewed by others

References

  • Anderson JD (2002) Modern compressible flow with historical perspective, 3rd edn. McGraw-Hill, New York

    Google Scholar 

  • Kleine H (2001) Flow Visualization. In: Ben-Dor G, Igra O, Elperin T (eds) Handbook of shock waves, vol 1. Academic Press, San Diego, pp 683–740

    Google Scholar 

  • Li H, Ben-Dor G (1996) Oblique-shock/expansion-fan interaction—analytical solution. AIAA J 34(2):418–421

    Article  Google Scholar 

  • Merzkirch W (1974) Flow visualization, 1st edn. Academic Press, New York

    Google Scholar 

  • North RJ (1954) A colour schlieren system using multicolor filters of a simple construction. NPL Aero Report 266, British National Physical Laboratory

  • Schardin H (1942) Die Schlierenverfahren und ihre Anwendungen. Ergebnisse der Exakten Naturwissenschaften 20:303–439. English translation available as NASA TT F12731, April 1970 (N70–25586)

  • Settles GS (2001) Schlieren and shadowgraph techniques: visualizing phenomena in transparent media 1st edn, corrected 2nd printing. Springer, Berlin

    Book  Google Scholar 

  • Yao Y, Li SG, Wu ZN (2013) Shock reflection in the presence of an upstream expansion wave and a downstream shock wave. J Fluid Mech 735:61–90

    Article  MathSciNet  Google Scholar 

Download references

Acknowledgments

The photographers of the aircraft photographs upon which the expansion fan/shock wave interaction was superimposed (in Fig. 1) are acknowledged in this section. The photographs used for the illustration were taken from the public domain. Store carriage photograph (Fig. 1a): Tech. Sgt. Kit Thomson, http://www.defenseimagery.mil/imagery.html?&guid=cba0c554e73a5f382306e789f6754cbd7b4f921f, accessed on 9 September 2014; Store release photograph (Fig. 1b): Staff Sgt. Michael B. Keller, http://www.flickr.com/photos/39955793@N07/4148070166/, accessed on 9 September 2014; Formation flying photograph (Fig. 1c): photographer unknown, http://www.af.mil/News/Photos.aspx?igphoto=2000593274, accessed on 9 September 2014; Engine inlet design photograph (Fig. 1d): Senior Airman DeAndre Curtiss, http://www.flickr.com/photos/usairforce/6192171330/in/photostream/, accessed on 9 September 2014.

Author information

Authors and Affiliations

  1. Aeronautic Systems Competency, Defence Peace Safety and Security, Council for Scientific and Industrial Research, Pretoria, 0001, South Africa

    Lara Nel & Kavendra Naidoo

  2. Flow Research Unit, School of Mechanical, Industrial and Aeronautical Engineering, University of the Witwatersrand, Johannesburg, 2050, South Africa

    Lara Nel & Beric Skews

Authors
  1. Lara Nel
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Beric Skews
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Kavendra Naidoo
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Lara Nel.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Nel, L., Skews, B. & Naidoo, K. Schlieren techniques for the visualization of an expansion fan/shock wave interaction. J Vis 18, 469–479 (2015). https://doi.org/10.1007/s12650-014-0253-y

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12650-014-0253-y

Keywords

Search

Navigation