Effect of Small Angles of Attack on Turbulence Generation in Supersonic Boundary Layers on Swept Wings

• Published in: Fluid dynamics Vol. 58; no. 3; pp. 371 - 380
• Main Authors: Kosinov, A. D., Kocharin, V. L., Liverko, A. V., Semenov, A. N., Semionov, N. V., Smorodsky, B. V., Tolkachev, S. N., Yatskikh, A. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.06.2023; Springer; Springer Nature B.V
• Subjects: Analysis; Angle of attack; Boundary layer; Boundary layer transition; Classical and Continuum Physics; Classical Mechanics; Cross flow; Engineering Fluid Dynamics; Fluid flow; Fluid- and Aerodynamics; Leading edges; Mach number; Physics; Physics and Astronomy; Reynolds number; Supersonic boundary layers; Swept wings; Turbulence; Turbulent boundary layer; supersonic boundary layer; angle of slip; experiments; angle of attack; swept wing; transition Reynolds number; linear stability theory; laminar-turbulent transition
• ISSN: 0015-4628; 1573-8507
• DOI: 10.1134/S0015462823600165

We present the new (for Mach numbers М = 3 and 3.5) and generalizing (for Mach numbers from 2 to 4) results of experimental investigations on the effect of small angles of attack on laminar-turbulent transition in the supersonic boundary layer on a swept wing with the leading-edge slip angle of 72°. The angle-of-attack variation has a strong effect on the transition Reynolds number. The transition Reynolds number decreases with increase in the Mach number. The measurements were carried out by means of a constant-temperature hot-wire anemometer using the proven procedure of determining the transition location. The e N method is used for the first time for numerically estimating the transition Reynolds numbers in the supersonic boundary layer on a swept wing with the leading-edge slip angle of 72°. The growth of the amplitudes of the steady and unsteady modes of the boundary layer crossflow are calculated in accordance with the linear stability theory, within the framework of the Lees–Lin system of equations. The numerical results indicate that, in accordance with the experimental results, laminar-turbulent transition in the boundary layer on the model swept wing is governed by the growth of stationary modes of the crossflow instability.