A short theoretical study of aircraft aerodynamic model equations with unsteady effects is presented. The aerodynamic forces and moments are expressed in terms of indicial functions or internal state variables. The first representation leads to aircraft integro-differential equations of motion; the second preserves the state-space form of the model equations. The formulations of unsteady aerodynamics is applied in two examples. The first example deals with a one-degree-of-freedom harmonic motion about one of the aircraft body axes. In the second example, the equations for longitudinal short-period motion are developed. In these examples, only linear aerodynamic terms are considered. The indicial functions are postulated as simple exponentials and the internal state variables are governed by linear, time-invariant, first-order differential equations. It is shown that both approaches to the modeling of unsteady aerodynamics lead to identical models.
Modeling of Aircraft Unsteady Aerodynamic Characteristics. Part 1: Postulated Models
1994
26 pages
Report
No indication
English
Aerodynamics , Aerodynamic characteristics , Aircraft configurations , Flight mechanics , Mathematical models , Unsteady aerodynamics , Aerodynamic forces , Differential equations , Equations of motion , Harmonic motion , Integral equations , Longitudinal stability , Parameter identification , Stability derivatives
Unsteady aerodynamic models for maneuvering aircraft
AIAA | 1993
|Unsteady Aerodynamic Models for Maneuvering Aircraft
British Library Conference Proceedings | 1993
|