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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2020, Vol. 41 ›› Issue (12): 124098-124098.doi: 10.7527/S1000-6893.2020.24098

• Fluid Mechanics and Flight Mechanics • Previous Articles     Next Articles

Hypersonic boundary layer transition over bodies with blunt nosetip

CHEN Suyu, JIANG Tao, CHANG Yu, HU Shouchao, LI Qiang, ZHANG Kouli   

  1. Hypervelocity Aerodynamics Institute, China Aerodynamics Research and Development Center, Mianyang 621000, China
  • Received:2020-04-15 Revised:2020-04-25 Published:2020-05-21
  • Supported by:
    National Key Research and Development Program of China (2016YFA0401201)

Abstract: To investigate hypersonic boundary layer transition and the effect of nosetip bluntness on transition, this study carries out experiments in both FD-14 and FD-14A shock tunnels. Integrated measurements including heat flux measurement, pressure disturbances measurement, and high-speed schlieren visualization are conducted. Results show that the transition Reynolds number as a function of Reynolds number based on nosetip bluntness exhibits a trend of transition-reversal. Power Spectral Density (PSD) analysis of pressure disturbances in the boundary layer is shown in the form of discrete contour maps in a streamwise direction. Development of second-mode waves, generation of turbulence and effect of the entropy layer on the boundary layer structure are visualized in images of high-speed schlieren. The entropy layer with an intense entropy gradient derived from large nosetip bluntness shows significant influence on the frequency spectral of pressure disturbances and flow structures of the boundary layer, playing an important role in the mechanism of transition-reversal. In addition, the effect of the Mach number should not be ignored.

Key words: hypersonic boundary layer transition, pressure disturbances, nosetip bluntness, transition-reversal, entropy layer

CLC Number: