1 IDENTIFICATION OF THE AERODYNAMIC COEFFICIENTS OF THE MULTIROLE MANEUVERABLE AIRCRAFT BASED ON UNSTEADY FLIGHT

The article describes the identification of the aerodynamic characteristics of the longitudinal motion of the maneuverable aircraft on the time domain by analysis of the data recorded in. The aerodynamic coefficients are represented as the sum of the components. The method permits to estimate each component of lift coefficient or pitching moment coefficient by itself. The aerodynamic wind tunnel database chosen as initial approximation of components. For analysis of algorithm, convergence it is used some arbitrary values as initial approximation of components the aerodynamic. The algorithm belongs to a class of Kaczmarz’s projection algorithms. It enables to compute points of nonlinear coefficient avoiding additional parameterization. It is presented results is processing of series of flights. Flight simulation with the estimation aerodynamic coefficient and the aerodynamic wind tunnel database was compared. 1. Nomenclature  – angle of attack M – Mach number . a  – aileron deflection, H  – horizontal stabilator deflection, F  – leading edge flap deflection A b – aerodynamic mean chord q – pitch rate V – air speed L C – lift coefficient m C – pitching moment coefficient 2. Introduction Modern aircraft of all kinds is a complex dynamic system with interaction between all of its subcomponents that is why final adjustment is possible only in actual operating condition. Experiments for determination of aerodynamic coefficients based on wind tunnel of scale model do not fit entirely natural flight condition. Tunnel data contamination can be significant, flight tests validation of aerodynamic coefficients is indispensable part of flighttesting experiment. It is rational to take into account characteristics of airplane exploitation (transonic or hypersonic flights, high angle of attack flights, etc.). The choose of the data processing methodology is critical for reduce number of experiment flights and to rise informative value significance of flight test. Issue of identification of aerodynamic coefficients of airplane is actual in development of new aerial vehicle, flight simulators and control algorithms. So identification of aerodynamic coefficients and parameters of airplane methodology consists of following steps:  Development of mathematical motion model of aircraft  Flight test planning  Validity check of mathematical model  Selection or development of estimation algorithm  Result validity check At the present moment, issue of non-linear identification is of current concern. 3. Aircraft and longitudinal model There is a flight model of multi-role maneuverable plane integrated circuit with an adaptive wing. A large range of operating altitudes and speeds the test aircraft leads to a OVCHARENKO VALERY, EGOROVA EVGENIA 2 number of significant features in the longitudinal channel characteristic of supersonic aircraft in general[1]:  Non-linear nature of pitching moment from angle of attack with intervals of static instability  Decrease pitch control power when Mach number is more than 1 and on high-angle-of-attack  Longitudinal static speed instability in transonic velocity  Reduce of damping in pitch in high angle of attack and high altitude. Modern integrated flight control systems bring significant influence in dynamic and flying qualities of aircraft. Research of aerodynamic coefficients complicates having of feedbacks in flight control system, ambiguous link between control stick, rudder pedals and control surfaces. There is affiliation of additional functions to flight controls (aileron droop, elevator for roll axis control on high angle of attack etc.). All this particularities conduct to non-linear aerodynamic coefficients significantly. In general terms, coefficients are functional relationship from kinematic parameters, similarity parameters and airplane configuration. The aerodynamic coefficients appear in the airplane equation of motion as the sum of components. The lift coefficient is       М C М C M C M C C M C