ZHANG Feng, YI Shihe, WU Yuyang, et al. Ratio of static pressure influence on cooling film of hypersonic optical dome based on NPLS[J]. 2019, 37(5): 762-769.
ZHANG Feng, YI Shihe, WU Yuyang, et al. Ratio of static pressure influence on cooling film of hypersonic optical dome based on NPLS[J]. 2019, 37(5): 762-769.DOI: 10.7638/kqdlxxb-2017.0154.
Ratio of static pressure influence on cooling film of hypersonic optical dome based on NPLS
Supersonic cooling gas film is a key technique applied to hypersonic imaging guided vehicle. For ratio of static pressure (RSP) is a major factor affecting the development of supersonic cooling film
it has great engineering significance to carry out a systematic research on the RSP. In this view
flow visualization tests of supersonic cooling film at different RSP levels based on nano-tracer planar laser scattering (NPLS) were carried out in a M6 hypersonic wind tunnel. Through the analysis of transient flow visualization images
the development process of the shear layer between the hypersonic mainstream and supersonic jet was studied. With the analysis of fractal dimension and intermittency
the distributions were
respectively
obtained of fractal dimension along the flow direction and intermittency factor along the normal direction
and the effect of RSP on turbulence development was analyzed. The evolution of supersonic gas flow field mainly includes four stages which can be characterized by laminar shear layer
disturbance occurrence
mixing of "mainstream-jet" shear layer and jet boundary layer
and formation of "large boundary layer". RSP has obvious influence on the wave structures
the film thickness and the turbulence degree of the flow field. The overall thickness of the gas film is positively related to the static pressure ratio along with the "condense" for a under-match RSP and the "inflation" for a over-match RSP. The film thickness of under-match state and match state increases slow first but then fast
meanwhile it is just opposite under over-match state. The turbulence breaking factor of under-pressure state and match state is generally smaller than that of the over-pressure state in the forepart of flow field
but it increases rapidly along the flow direction. Moreover
the match state has the largest turbulence breaking factor and the highest degree of turbulence level compared with the other states.
关键词
Keywords
references
ECKERT E R G. Gas-to-gas film cooling[J]. Journal of Engineering Physics and Thermophysics, 1970, 19(3):1091-1101. doi:10.1007/BF00826233
GOLDSTEIN R J, ECKERT E R G. Film cooling with air and helium injection through a rearward-facing slot into a supersonic air flow[J]. AIAA Journal, 1966, 4(6):981-985. doi:10.2514/3.3591
ECKERT E R G. Transpiration and film cooling[C]. Heat-Transfer Symposium, 1952: 195-210.
SEBAN R A, BACK L H. Velocity and temperature profiles in turbulent boundary layers with tangential injection[J]. Journal of Heat Transfer, 1962, 84(1):45-54. doi:10.1115/1.3684292
JUHANY K A, HUNT M L. Flowfield measurements in supersonic film cooling including the effect of shock-wave interaction[J]. AIAA Journal, 1994, 32(3):578-585. doi:10.2514/3.12024
TAKESHI K, GORO M, FUMIEI O, et al. Effect of film cooling/regenerative cooling on scramjet engine performances[J]. Propulsion and Power, 1994, 10(5):618-624.
FU J. Study on the supersonic cooling film of the hypersonic optical dome and its mechanism of aero optics[D]. Changsha: National University of Defense Technology, 2017. (in Chinese)
HUANG K, MA H S. Numerical simulation on cooling characteristics of plate film from backward-expanding shoulder armhole[J]. Acta Aerodynamica Sinica, 2017, 35(6):866-869.
YI S H, ZHAO Y X, TIANL F, et al. The application of NPLS on the visualization of supersonic turbulent flow[C]. Modern Experimental Aerodynamic Meeting, 2007. (in Chinese)
YI S H, HE L, ZHAO Y X, et al. A flow control study of a supersonic mixing layer via NPLS[J]. Science in China Series G:Physics, Mechanics Astronomy, 2009, 52(12):2001-2006. doi:10.1007/s11433-009-0301-0
CHEN Z, YI S H, HE L, et al. An experimental study on fine structures of supersonic laminar/turbulent flow over a back-ward-facing step based on NPLS[J]. Chinese Science Bulletin, 2012, 57(6):584-590. doi:10.1007/s11434-011-4888-y
TIAN L F. Mechanism study of fine structures and aero-optiacal effects of supersonic flow around an optical dome[D]. Changsha: National University of Defense Technology, 2011. (in Chinese)
SREENIVASAN K R. Fractals and multifractals in fluid turbulence[J]. Ann Rev Fluid Mech, 1991, 23:539-600. doi:10.1146/annurev.fl.23.010191.002543
PRASAD R R, SREENIVASAN K R. The measurement and interpretation of fractal dimensions of the scalar interface in turbulent flows[J]. Physics of Fluids A:Fluid Dynamics (1989-1993), 1990, 2(5):792-807. doi:10.1063/1.857733
RACHID D. Using Canny's criteria to derive a recursively implemented optimal edge detector[J]. International Journal of Computer Vision, 1987, 1(2):167-187. doi:10.1007/BF00123164
JOHN C. A computational approach to edge detection[J]. Pattern Analysis and Machine Intelligence, IEEE Transactions on, 1986, (6):679-698. doi:10.1109/TPAMI.1986.4767851