Control of Nonlinear Stage of the Laminar-Turbulent Transition on an Airfoil by Dis-tributed Suction through a Finely Perforated Surface

Read more Abstract
The results of experimental investigations of the influence of distributed suction through a finely perforated surface on the spatial development of perturbations of the straight wing boundary layer at the nonlinear stage of its evolution are presented in this article. It was found that distributed suction reduces the intensity of integral pulsations for natural disturbances by 90 times. A spectral analysis of disturbances showed a decrease in the intensity of high-frequency fluctuations in a narrow frequency band by two orders of magnitude for natural and forced disturbances generated by an external acoustic field. It was found that the distributed suction affects the average flow, namely, when the suction is on, the turbulent state of the boundary layer is eliminated, its separation near the trailing edge of the wing and the laminar flow is defined in the boundary layer.

Keywords
boundary layer, nonlinear stage, stability, Tollmien – Schlichting waves, distributed suction, disturbance spectrum
Funding
The work was partially carried out within the framework Of the program of fundamental scientific research of the state academies of Sciences for 2013–2020 (project AAAA17-117030610128-8), within the framework of providing distributed suction and with state support for research conducted under the leadership of leading scientists in Russian universities, agreement No. 075-15-2019-1923
УДК 532.526

Control of Nonlinear Stage of the Laminar-Turbulent Transition on an Airfoil by Dis-tributed Suction through a Finely Perforated Surface (RUS)