Abstract
Experiments are conducted on a planar ramp in high-enthalpy flow, with gaseous hydrogen injected through a porthole at the ramp surface. The ramp is covered in a thin layer of temperature-sensitive luminescent paint, originally intended to allow surface heat-flux measurements; however, anomalous transient features are identified in high-speed recorded images of the paint emission, which are postulated as originating from excitation by OH* chemiluminescence produced during hydrogen combustion. By assuming the OH*-induced emission to occur on much shorter timescales than surface temperature changes, it is possible to extract this pseudo-OH* signal, allowing time-resolved combustion features to be investigated. Two cases are examined, the first exhibiting marginal combustion and the second with more robust ignition. For the first, the weak OH* excitation allows concurrent temperature and heat-flux distributions to be derived. In both cases, the time-averaged combustion distribution shows intense ignition in the immediate vicinity of the injection hole, with extended fingers of weaker combustion extending downstream; the latter are assumed to be associated with the main counter-rotating vortex pair produced by the injection. By examining shorter timescales, however, it is revealed that these combustion fingers are not steady features but rather the time-integrated result of more localized ignition streaks convecting downstream. Overall, the presence of combustion is associated with higher surface heat fluxes. The pseudo-OH* visualization method is a possible alternative to conventional OH* chemiluminescence for wall-bounded combusting flows, allowing a conventional visible-wavelength camera to be employed in place of a UV-sensitive imaging system.
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References
Ames Research Staff (1953) Equations, tables, and charts for compressible flow. NACA Report 1135
Colket MB, Spadaccini LJ (2001) Scramjet fuels autoignition study. J Prop Power 17(2):315–323
Cook W, Felderman E (1966) Reduction of data from thin-film heat-transfer gages: a concise numerical technique. AIAA J 4(3):561–562
De Leo M, Saveliev A, Kennedy LA, Zelepouga SA (2007) OH and CH chemiluminescence in opposed flow methane oxy-flames. Comb Flame 149:435–447
Gamba M, Mungal MG (2015) Ignition, flame structure and near-wall burning in transverse hydrogen jets in supersonic crossflow. J Fluid Mech 780:226–273
Gerhold T, Friedrich O, Evans J, Galle M (1997) Calculation of complex three-dimensional configurations employing the DLR TAU-code. AIAA Paper No. 97-0167
Gruber MR, Nejad AS, Chen TH, Dutton JC (1995) Mixing and penetration studies of sonic jets in a mach 2 freestream. J Prop Power 11(2):264–273
Hannemann K (2003) High enthalpy flows in the HEG shock tunnel: Experiment and numerical rebuilding. In: 41st AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nevada
Hardalupas Y, Orain M (2007) Local measurements of the time-dependent heat release rate and equivalence ratio using chemiluminescent emission from a flame. Comb Flame 139:188–207
Kawai S, Lele SK (2010) Large-eddy simulation of jet mixing in supersonic crossflows. AIAA J 48(9):2063–2083
Krek RM, Jacobs P (1993) STN, shock tube and nozzle calculations for equilibrium air. Department of Mechanical Engineering Report 2/93, The University of Queensland
Laurence S, Lieber D, Schramm JM, Hannemann K, Larsson J (2015) Incipient thermal choking and stable shock-train formation in the heat-release region of a scramjet combustor. Part I: Shock-tunnel experiments. Comb Flame 162(4):921–931
Laurence SJ, Karl S, Hannemann K (2013a) Experimental and numerical investigation of the HyShot II flight experiment. In: Proceedings of the 29th International Symposium on Shock Waves (ISSW 29), Madison, WI, USA
Laurence SJ, Karl S, Schramm JM, Hannemann K (2013b) Transient fluid-combustion phenomena in a model scramjet. J Fluid Mech 722:85–120
Laurence SJ, Ozawa H, Schramm JM, Hannemann K (2019) Heat-flux measurements on a hypersonic inlet ramp using fast-response temperature sensitive paint. Exp Fluids 60:70
Liu Q, Baccarella D, McGann B, Lee T (2019) Cavity-enhanced combustion stability in an axisymmetric scramjet model. AIAA J 57(9):3898–3909
Mahesh K (2013) The interaction of jets with crossflow. Ann Rev Fluid Mech 45(1):379–407
Micka DJ, Torrez SM, Driscoll JF (2009) Heat release distribution in a dual-mode scramjet combustor - measurements and modeling. AIAA Paper 2009-7362
Najm HB, Paul PH, Mueller CJ, Wyckoff PS (1998) On the adequacy of certain experimental observables as measurements of flame burning rate. Comb Flame 113:312–332
Ozawa H, Laurence SJ, Schramm JM, Wagner A, Hannemann K (2015) Fast-response temperature-sensitive-paint measurements on a hypersonic transition cone. Exp Fluids 56(1):1853
Schefer R, Kulatilaka W, Patterson B, Settersten T (2009) Visible emission of hydrogen flames. Comb Flame 156:1234–1241
Snavely BB, Peterson OG, Reithel RF (1967) Blue laser emission from a flashlamp-excited organic dye solution. Appl Phys Lett 11(9):275–276
Sun M, Hu Z (2018) Formation of surface trailing counter-rotating vortex pairs downstream of a sonic jet in a supersonic crossflow. J Fluid Mech 850:551–583
Acknowledgements
The authors gratefully acknowledge the HEG technical staff, particularly Ingo Schwendtke and Bartek Klaskala, for support and assistance during this experimental campaign.
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Laurence, S.J., Ozawa, H., Martinez Schramm, J. et al. Combined combustion and heat-flux measurements on a supersonic jet-in-crossflow configuration using luminescent paint. Exp Fluids 62, 154 (2021). https://doi.org/10.1007/s00348-021-03246-z
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DOI: https://doi.org/10.1007/s00348-021-03246-z