TY - GEN
T1 - Repid growth of unsteady finite-amplitude perturbations in a supersonic boundary-layer flow
AU - Watanabe, Daisuke
AU - Maekawa, Hiroshi
N1 - Funding Information:
This study was partly supported by Grants-in-Aid for scientific research (21560165, 24656518) from Japanese Ministry of Education, Culture, Sports, Science and Technology.
PY - 2015
Y1 - 2015
N2 - Spatial numerical simulations (SNS) are performed to study transition to turbulence in a supersonic flat plate boundary layer forced by finite amplitude perturbations, where the freestream Mach numbers is 2.5 with the isothermal wall condition. Three-dimensional isotropic disturbances are superimposed on the laminar profile for Reynolds number based on the displacement thickness δ∗ of 1000 at the inlet plane of the computational domain. The effects of the peak location of the disturbance spectrum and the magnitude distribution in the wall normal direction are analyzed. Numerical results indicate that energy spectra with a peak located at around the wavenumber of kmax=1.0 play an important role to induce transition to turbulence. The disturbance at lower wavenumbers with concomitant turbulence in the free stream shows an early appearance of hairpin-like structure in the transition region. The vortical structures on set of transition to turbulence rapid evolving to a hairpin packet with fine secondary structures downstream are shown in this paper, which is an inherent structure induces transition to turbulence in the supersonic boundary layer.
AB - Spatial numerical simulations (SNS) are performed to study transition to turbulence in a supersonic flat plate boundary layer forced by finite amplitude perturbations, where the freestream Mach numbers is 2.5 with the isothermal wall condition. Three-dimensional isotropic disturbances are superimposed on the laminar profile for Reynolds number based on the displacement thickness δ∗ of 1000 at the inlet plane of the computational domain. The effects of the peak location of the disturbance spectrum and the magnitude distribution in the wall normal direction are analyzed. Numerical results indicate that energy spectra with a peak located at around the wavenumber of kmax=1.0 play an important role to induce transition to turbulence. The disturbance at lower wavenumbers with concomitant turbulence in the free stream shows an early appearance of hairpin-like structure in the transition region. The vortical structures on set of transition to turbulence rapid evolving to a hairpin packet with fine secondary structures downstream are shown in this paper, which is an inherent structure induces transition to turbulence in the supersonic boundary layer.
UR - http://www.scopus.com/inward/record.url?scp=85034455206&partnerID=8YFLogxK
M3 - 会議への寄与
AN - SCOPUS:85034455206
T3 - 9th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2015
BT - 9th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2015
PB - TSFP-9
T2 - 9th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2015
Y2 - 30 June 2015 through 3 July 2015
ER -