ON NEW METHODS FOR BOUNDARY-LAYER FLOW LAMINARIZATION

New methods for the laminarization of the boundary-layer flow on straight wings are offered. The laminar-turbulent transition is assumed to be due to acoustic influence and/or wing-surface vibration. The basis for the methods is in the mutual cancellation of Tollmien-Schlichting waves excited in the vicinity of the leading edge of the wing and over the artificial roughness of the streamlined surface. This cancellation is ensured by the special choice of the roughness form. Calculations are carried out to demonstrate the efficiency of the methods. A finite Reynolds number approach is used to obtain an adequate quantitative description of the phenomena in question.