Method of estimating the number M of occurrence of transonic flutter of aerodynamic control surfaces of supersonic aircraft and aerospace systems

Evaluation of the characteristics of aerodynamic surfaces in transonic air flow by theoretical methods remains an actual scientific and applied problem that must be solved to ensure the safety of flights of supersonic aircraft and aerospace systems at transonic flight speeds. Difficulties in solving the problem are due to the need to take into account the effect of air compressibility on the change in the characteristics of the aerodynamic profiles of supersonic aircraft in the transonic range of flight speeds. In some works, the influence of air compressibility on the change in the characteristics of aerodynamic profiles is estimated using various corrections.Additional difficulties in evaluating the characteristics of the aerodynamic surfaces of supersonic aircraft at transonic flight speeds arise in the formation of compression jumps on the surface of the aerodynamic profile, the effect of which cannot be determined by these corrections.The article proposes a method for estimating the M number, in which the occurrence of transonic flutter of the aerodynamic control surfaces of supersonic aircraft and aerospace systems is possible.The method is based on the analysis of the characteristics of the interaction of the oscillations of the sealing jumps with the oscillations of the aerodynamic control surfaces and on the basis of the analysis of the patterns of expansion of the local supersonic air flow on the surface of the aerodynamic profile.The possibility of using this method for preliminary estimation of the number M of transonic flutter of aerodynamic control surfaces is substantiated by comparing the results obtained using the proposed method with the results obtained in a laboratory experiment during blowing of a wing model with a control surface.The obtained results can be used to carry out a preliminary approximate assessment of the M number, in which transonic flutter of the aerodynamic control surfaces of supersonic aircraft and aerospace systems is possible, and in the preparation of recommendations to the flight crew regarding the features of controlling supersonic aircraft in the transonic range of M flight numbers.