Cancellation of Tollmien–Schlichting waves with surface heating

Abstract

Two-dimensional boundary layer flows in quiet disturbance environments are known to become unstable to Tollmien–Schlichting waves. The experimental work of Liepmann et al. (J Fluid Mech 118:187–200, 1982), Liepmann and Nosenchuck (J Fluid Mech 118:201–204, 1982) showed how it is possible to control and reduce unstable Tollmien–Schlichting wave amplitudes using unsteady surface heating. We consider the problem of an oncoming planar compressible subsonic boundary layer flow with a three-dimensional vibrator mounted on a flat plate, and with surface heating present. It is shown using asymptotic methods based on triple-deck theory that it is possible to choose an unsteady surface heating distribution to cancel out the response due to the vibrator. An approximation based on the exact formula is used successfully in numerical computations to confirm the findings. The results presented here are a generalisation of the analogous results for the two-dimensional problem in Brennan et al. (J Fluid Mech 909:A16-1, 2020).

Optimizing control of stationary cross-flow vortices excited by surface roughness

“…Surface temperature 14,15,46,47 , plasma actuators [48][49][50] and surface compliance 51,52 are just some of the methods that have been utilised as a means of controlling transition in boundary layers. Dynamic wall modification was utilised experimentally by Amitay et al 53 to excite and control TS disturbances on a flat plate.…”

A CFD Tutorial in Julia: Introduction to Laminar Boundary-Layer Theory

“…Since the focus of the present paper is the fundamentals of laminar boundary-layer theory, the details will not be provided about advanced researches. However, readers who are interested in details may check [9][10][11][12] for subsonic boundary-layer transition, Ref. [13][14][15][16][17][18][19][20][21] for supersonic/hypersonic boundary-layer transition, and Ref.…”

A CFD Tutorial in Julia: Introduction to Compressible Laminar Boundary-Layer Flows

“…We provide the GitHub link of the codes, installation instructions, and required packages in Appendix A. Advanced boundary-layer topics are beyond the scope of this paper, interested readers are referred to additional references [22][23][24][25] for subsonic boundary-layer transition, references [26][27][28][29][30][31][32][33][34] for supersonic/hypersonic boundary-layer transition, and references [35][36][37] for flow separation. The other research studies where boundary-layer flow is involved are presented in the references [38][39][40][41][42][43].…”