Abstract
The interactions of multiple streamwise vortices have the potential to enhance the fuel/air mixing process in the supersonic flowfields intrinsic of scramjet combustors. As part of an ongoing experimental study on the mixing enhancement capabilities of imposed streamwise vortex interactions, high quality visualizations of the resulting turbulent vortical flowfields have been obtained with the filtered Rayleigh scattering technique. By visualizing the structure and organization of the studied flowfields, which are generated by a ramped strut injector in a Mach 2.5 flow, insight into the relevant flow physics governing the vortex interactions is obtained. Filtered Rayleigh scattering is a non-intrusive laser-based diagnostic technique that images the light scattered from the constituent gas molecules of a flow, thus providing a distinct advantage over other flow visualization techniques, in that it is not required to seed the flow with gaseous or particulate flow tracers. However, because the Rayleigh scattered signal is relatively weak, it is easily obscured by light scattered from other sources, necessitating the implementation of a molecular notch filter. This fact, combined with the complex supersonic turbulent vortical flows that are of interest, makes the application of the filtered Rayleigh scattering technique challenging and non-trivial. This work will highlight the experimental considerations necessary to achieve successful visualization of the flows of interest by presenting the methods used to image a single downstream station of a non-merging vortex interaction mode. The resulting flow visualizations illustrate the highly turbulent nature of the probed flowfield while confirming the behavior observed in previous experiments.
Graphical abstract
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Boguszko M, Elliott GS (2005) On the use of filtered Rayleigh scattering measurements in compressible flows and thermal fields. Exp Fluids 38:33–49
Boguszko M, Elliott GS (2005) Property measurement utilizing atomic/molecuar filter-based diagnostics. Prog Aerosp Sci 41:93–142
Doster JC, King PI, Gruber MR, Carter CD, Ryan MD, Hsu KY (2009) In-stream hypermixer fueling pylons in supersonic flow. J Propul Power 25:885–901
Elliott GS, Glumac N, Carter C (2001) Molecular filtered Rayleigh scattering applied to combustion. Meas Sci Technol 12:452–466
Forkey JN, Lempert WR, Miles RB (1997) Corrected and calibrated \(I_2\) absorption model at frequency-doubled Nd:YAG laser wavelengths. Appl Optics 36:6729–6738
George J, Jenkins T, Miles RB (2014) Diagnosis of high speed flows using filtered Rayleigh scattering. 30th AIAA Aerodynamic Measurement Technology and Ground Testing Conference, Atlanta, Georgia, AIAA 2014-2231
Ground C, Thumiah D, Maddalena L (2015) Design and application of filtered Rayleigh scattering experiments for mixing studies of new strut injectors for scramjets. 31st AIAA Aerodynamic Measurement Technology and Ground Testing Conference, Dallas, Texas, AIAA 2015-2567
Kutschenreuter P (2000) Supersonic flow combustors. In: Curran ET (ed), Murthy SNB (ed) Scramjet propulsion, Progress in astronautics and aeronautics, Vol. 189, American Institute of Aeronautics and Astronautics, Reston, Virginia
Maddalena L (2007) Investigations of injectors for scramjet engines. Dissertation, Virginia Polytechnic Institute and State University
Maddalena L, Vergine F, Crisanti M (2014) Vortex dynamics studies in supersonic flow: merging of co-rotating streamwise vortices. Phys Fluids 26:046101
Miles RB, Lempert W, Forkey J (1991) Instantaneous velocity fields and background suppression by filtered Rayleigh scattering. 19th Aerospace Sciences Meeting, Reno Nevada, AIAA 91-0357
Poggie J, Erbland PJ, Smits AJ, Miles RB (2004) Quantitative visualation of compressible turbulent shear flows using condensate-enhanced Rayleigh scattering. Exp in Fluids. 37:438–454
Sunami T, Wendt M, Nishioka M (1998) Supersonic mixing and combustion control using streamwise vortices. 34th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, Cleveland, Ohio, AIAA 1998-3271
Vergine F (2014) Vortex dynamics studies in supersonic flow. Dissertation, The University of Texas at Arlington
Vergine F, Ground C, Maddalena L (2015) Experimental study of strut injectors for scramjet combustors: Total pressure losses in a selected supersonic streamwise vortex interaction mode. 20th AIAA International Space Planes and Hypersonic Systems and Technologies Conference, Glasgow, Scotland, AIAA 2015-3589
Vergine F, Maddalena L (2015) Study of two supersonic streamwise vortex interactions in a Mach 2.5 flow: merging and no merging configurations. Phys Fluids 27:076102
Waitz IA, Qiu YJ, Manning TA, Fung AKS, Elliot JK, Kerwin JM, Krasnodebski JK, O’Sullivan MN, Tew DE, Greitzer EM, Marble FE, Tan CS, Tillman TG (1997) Enhanced mixing with streamwise vorticity. Prog Aerospace Sci 33:323–351
Yalin AP, Miles RB (1999) Ultraviolet filtered Rayleigh scattering temperature measurements with a mercury filter. Opt Lett 24:590–592
Acknowledgments
This research has been sponsored [in part] by the NASA Langley Research Center through the NASA Research Announcement Grant No. NNX12AG4A with Dr. Tomasz G. Drozda as the technical monitor.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ground, C., Maddalena, L. Visualization of supersonic turbulent vortical flows with filtered Rayleigh scattering. J Vis 20, 75–86 (2017). https://doi.org/10.1007/s12650-016-0382-6
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12650-016-0382-6