MODEL OF THE UNSTEADY AERODYNAMIC CHARACTERISTICS AT HIGH AOA WITH NONLINEAR DEPENDENCY IN ANGULAR RATE

摘要

Experimental study of unsteady aerodynamic characteristics of a passenger aircraft over an extended angle-of-attack range was carried out using a series of forcedoscillation tests. Strong nonlinear effects, namely, an influence of oscillation frequency on aerodynamic derivatives and hysteresises with multiple self-intersections, were observed. The experimental results enable an influence of a pitch rate on unsteady pitch moment to be analyzed. A model of unsteady aerodynamic characteristics with Nonlinear Dependency in Angular Rate (NDAR) describing the main dynamic effects observed in the experiment was developed. The proposed model is compared with linear, state-space and neural network models.