Influence of the leading-edge bluntness radius of a plate on the response of flat-plate boundary layer to an N-wave at Mach number M = 2

• Published in: Thermophysics and aeromechanics 2023-03, Vol.30 (2), p.227-237
• Main Authors: Kosinov, A. D., Semionov, N. V., Yatskikh, A. A., Kocharin, V. L., Shmakova, A. V.
• Format: Article
• Language: English
• Subjects: Boundary layer transition; Frequency ranges; Laminar boundary layer; Leading edges; Mach number; Nonuniformity; Physics; Physics and Astronomy; Thermodynamics; Turbulent boundary layer; Wind tunnels
• ISSN: 1531-8699; 0869-8643; 1531-8699
• DOI: 10.1134/S086986432302004X

An experimental study of the influence of the leading-edge radius of a blunt plate on the response of boundary layer on this plate to an N-wave at Mach 2 was carried out. Three flat-plate models with different leading-edge bluntness radii, r = 0.05, 0.5, and 2.5 mm, were used in the experiments. The oncoming-flow disturbances were created using a generator provided on the sidewall of the test section of the T-325 wind tunnel of ITAM SB RAS. It is found that behind the N-wave in the oncoming flow, there forms an extended region with an increased level of flow pulsations whose spectrum contains the amplitudes increased both in low-frequency and high-frequency range of the spectrum compared to the undisturbed freestream. It was shown that, under experimental conditions, the flow non-uniformity generated by the N-wave can exert a greater influence on the flat-plate boundary layer laminar-turbulent transition with increasing leading-edge bluntness radius.