1 Laminar Flow Control: TsAGI Experience and Investigations

The represented paper is a brief overview of some activities in laminar flow control area being performed in Central Aerohydrodynamic Institute named after prof. N.E. Zhukovsky (TsAGI) in Russia. These efforts are focused on the improvement of the existing laminar flow control methods and on the development the new ones. The investigations have demonstrated effectiveness of aircraft surface laminarization application with the aim of friction drag re-duction. The opportunity of considerable delaying of laminar-turbulent transition due to special wing profile geometry (natural laminar flow – NLF) and using boundary layer suc-tion and surface cooling (forced laminar flow control – FLFC) has been verified at sub- and supersonic speeds through various wind tunnels testing in TsAGI and during flying labora-tory experiments in Flight Research Institute (LII). The investigations on using of hybrid laminar flow control (HLFC) system for friction drag reduction were carried out. The new techniques of laminar flow control were developed, in particular the method of local heating of the wing leading edge, boundary layer laminarization by means of receptivity control, electrohydrodynamic control of laminar-turbulent transition. Nomenclatur