Experimental study of the effect of a passive porous coating on disturbances in a hypersonic boundary layer 2. Effect of the porous coating location

• Published in: Journal of applied mechanics and technical physics 2016-09, Vol.57 (5), p.873-878
• Main Authors: Lukashevich, S. V., Morozov, S. O., Shiplyuk, A. N.
• Format: Article
• Language: English
• Subjects: Amplitudes; Angle of attack; Applications of Mathematics; Boundary layer; Boundary layer stability; Classical and Continuum Physics; Classical Mechanics; Coating; Coating effects; Disturbances; Flow stability; Fluid flow; Fluid- and Aerodynamics; Hypersonic boundary layer; Mach number; Mathematical Modeling and Industrial Mathematics; Mechanical Engineering; Physics; Physics and Astronomy; Reduction; Reynolds number; Stagnation temperature; Zero angle of attack
• ISSN: 0021-8944; 1573-8620
• DOI: 10.1134/S002189441605014X

The effect of the location of a passive porous coating on natural disturbances in a hypersonic boundary layer is studied experimentally. The experiments are performed in the flow around a sharp cone aligned at a zero angle of attack with the free-stream Mach number M ∞ = 5.8, stagnation temperature T 0 = 370 ± 5 K, and unit Reynolds numbers Re 1∞ = 2.6 · 10 6 , 4.6 · 10 6 , 6.6 · 10 6 , and 10 7 m −1 . The wave characteristics of the boundary layer are calculated with the use of the linear stability theory for flow parameters corresponding to experimental values. A comparison of experimental and predicted results shows that the presence of a porous coating in the region where the second mode is unstable leads to reduction of its amplitude at the measurement point, whereas the presence of a porous coating in the region of second mode stability leads to enhancement of the amplitude.