Babenko A. Diagnostics of the Aircraft's External Contour in Flight by its Thermal Fields

The thesis is devoted to the problems of increasing safety, namely the: diagnosis aerodynamic condition of the external contour of the aircraft in flight. A thermal method of diagnostics for diagnosis the state of the aircraft's external contour has been adapted for use in real-time during flight of the aircraft. New mathematical models for proposed method have been developed. The parameters that affect the behavior of temperature gradient which occurs behind the damage have been studied. These parameters are: the speed and angle of attack of the aircraft, the shape of the wing profile, the shape of damage, the place of appearance of damage. General requirements for diagnostic system have been justified. Structural design and construction thermocouple sensors "skin-rivet" have been developed for use in the system. Thermal Reynolds number, which relates the temperature difference between the undisturbed airflow with the temperature difference between the damaged and undamaged areas of the external contour has been proposed. The angle of attack dependence which linked the lift change with the change of the wing area as a result of damage with and temperature difference has been obtained. The choice of the airfoils' types and the initial conditions for the simulation of flow around the external contour have been grounded. Through computer simulation and wind tunnel experiment was found that temperature difference in the boundary layer between the damaged and undamaged areas of the external contour has been developed. By placing temperature measurement sensors on the surface of the aircraft's external contour, we can get data about the moment and location of the damage. Knowing the information of the current flight altitude and flight speed, as well as the angle of attack it is possible to obtain information on the extent of damage. Based on wind tunnel experiment the potential possibility of real-time diagnostics the state of the external contour of the aircraft in flight in based on monitoring changes in the external contour of thermal fields has been proved. Real-time diagnostics of external contour of aircraft and its wings, in particular, makes it possible to warn or prevent emergency situations and thus improve the flight safety. The obtained information about the state of the external contour can be used in control system for the reconstruction of control actions to warn or prevent emergency situations and, thus improve the flight safety.