Influence of the leading-edge bluntness radius of a plate on the response of boundary layer on this plate to an N-wave at Mach number M = 2
A.D. Kosinov, N.V. Semionov, A.A. Yatskikh, V.L. Kocharin, A.V. Shmakova
Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Keywords: supersonic boundary layer, N-wave, weak shock waves, longitudinal vortices, flat plate, hot-wire anemometry
Abstract
An experimental study of the influence of the leading-edge bluntness radius of a plate on the response of boundary layer on this plate to an N-wave at Mach number M=2 was carried out. Three flat-plate models with 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 installed 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 features amplitudes increased both in the low-frequency and in the high-frequency portion of the spectrum compared to the undisturbed free flow. It was shown that, under experimental conditions, the flow non-uniformity generated by the N-wave can exert a greater influence on the laminar-turbulent transition in the boundary layer of a flat plate with an increase in the leading-edge bluntness radius.
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