Abstract
Planar laser Rayleigh scattering (PLRS) from condensed CO2 particles is used to visualize flow structure in a Mach 5 wind tunnel undergoing unstart. Detailed flow features such as laminar/turbulent boundary layers and shockwaves are readily illustrated by the technique. A downstream transverse air jet, inducing flow unchoking downstream of the jet, is injected into the free stream flow of the tunnel, resulting in tunnel unstart. Time sequential PLRS images reveal that the boundary layer growth/separation on a surface with a thick turbulent boundary layer, initiated by the jet injection, propagates upstream and produces an oblique unstart shock. The tunnel unstarts upon the arrival of the shock at the inlet. In contrast, earlier flow separation on the opposite surface, initially supporting a thin laminar boundary layer, is observed when a jet induced bow shock strikes that surface. The resulting disturbance to this boundary layer also propagates upstream and precedes the formation of an unstart shock.
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References
Curran ET, Heiser WH, Pratt DT (1996) Fluid phenomena in scramjet combustion systems. Annu Rev Fluid Mech 28:323–360
Hawkins WR, Marquart EJ (1995) Two-dimensional generic inlet unstart detection at Mach 2.5–5.0. In: 6th international aerospace planes and hypersonics technologies conference, Chattanooga
Heiser WH, Pratt DT (1993) Hypersonic air breathing propulsion. In: AIAA education series, Washington
Humble RA, Scarano F, van Oudheusden BW (2006) Experimental study of an incident shock wave/turbulent boundary layer interaction using PIV. In: 36th AIAA fluid dynamics conference and exhibit, San Francisco
Kodera M, Tomioka S, Kanda T, Mitani T, Kobayashi K (2003) Mach 6 test of a scramjet engine with boundary-layer bleeding and two-staged fuel injection. In: 12th AIAA international space planes and hypersonic systems and technologies, Norfolk
Mashio S, Kurashina K, Bamba T, Okimoto S, Kaji S (2001) Unstart phenomenon due to thermal choke in scramjet module. In: AIAA/NAL-NASDA-ISAS 10th international space planes and hypersonic systems and technologies conference, Kyoto
McDaniel KS, Edwards JR (2001) Three-dimensional simulation of thermal choking in a model scramjet combustor. In: 39th aerospace sciences meeting and exhibit, Reno
Miles RB, Lempert WR (1997) Quantitative flow visualization in unseeded flows. Annu Rev Fluid Mech 29:285–326
O’Byrne S, Doolan M, Olsen SR, Houwing AFP (2000) Analysis of transient thermal choking processes in a model scramjet engine. J Propuls Power 16:808–814
Pagella A, Rist U (2005) Direct numerical simulations of shock-boundary layer interaction at Ma = 6. Comput Sci High Perform Comput 88:123–140
Poggie J, Erbland PJ, Smits AJ, Miles RB (2004) Quantitative visualization of compressible turbulent shear flows using condensate-enhanced Rayleigh scattering. Exp Fluids 37:438–454
Rodi PE, Emami S, Trexler CA (1996) Unsteady pressure behavior in a ramjet/scramjet inlet. J Propuls Power 12:486–493
Sato S, Izumikawa M, Tomioka S. Mitani T (1997) Scramjet engine test at Mach 6 flight condition. In: 33rd AIAA/ASME/SAE/ASEE joint propulsion conference and exhibit, Seattle
Shimura T, Mitani T, Sakuranaka N, Izumikawa M (1998) Load oscillations caused by unstart of hypersonic wind tunnels and engines. J Propuls Power 14:348–353
Tam C, Eklund D, Behdadnia R (2008) Influence of downstream boundary conditions on scramjet-isolator simulations. In: 26th AIAA applied aerodynamics conference, Honolulu
Valdivia A, Yuceil KB, Wagner JL, Clemens NT, Dolling DS (2009) Active control of supersonic inlet unstart using vortex generator jets. In: 39th fluid dynamics conference and exhibit, San Antonio
Wagner JL, Yuceil KB, Valdivia A, Clemens NT, Dolling DS (2008) PIV measurements of the unstart process in a supersonic inlet/isolator. In: 38th fluid dynamics conference and exhibit, Seattle
Wagner JL, Yuceil KB, Valdivia A, Clemens NT, Dolling DS (2009a) Experimental investigation of unstart in an inlet/isolator model in Mach 5 flow. AIAA J 47:1528–1542
Wagner JL, Yuceil KB, Clemens NT (2009b) PIV measurements of unstart of an inlet-isolator model in a Mach 5 flow. In: 39th fluid dynamics conference and exhibit, San Antonio
Wang X, Le J (2000) Computations of inlet/isolator for SCRAMjet engine. J Thermal Sci 9:334–338
Wieting AR (1976) Exploratory study of transient unstart phenomena in a three-dimensional fixed-geometry scramjet engine. NASA technical note: TN D-8156
Wu P, Lempert WR, Miles RB (2000) Megahertz pulse-burst laser and visualization of shock-wave/boundary-layer interaction. AIAA J 38:672–679
Wutson EC, Murphy JD, Rose WC (1969) Investigation of laminar and turbulent boundary layers interacting with externally generated shock waves. NASA technical note, NASA TN D-5512
Acknowledgments
This work is sponsored by the Department of Energy sponsored Predictive Science Academic Alliance Program (PSAAP) at Stanford University. We thank Dr. Mirko Gamba for useful discussions.
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Do, H., Im, Sk., Mungal, M.G. et al. Visualizing supersonic inlet duct unstart using planar laser Rayleigh scattering. Exp Fluids 50, 1651–1657 (2011). https://doi.org/10.1007/s00348-010-1028-4
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DOI: https://doi.org/10.1007/s00348-010-1028-4