Efficient Unsteady Model Estimation Using Computational and Experimental Data

Abstract

Improving aircraft simulations for pilot training in loss-of-control and stalled conditions is one goal of NASA research in the System Wide Safety Program. One part of this effort is to develop appropriate generic aerodynamic models that provide representative responses in simulation for a given class of aircraft. In this part of the flight envelope nonlinear unsteady responses are often present and may require an extended aerodynamic model compared to that used in the conventional flight envelope. In this preliminary study, two objectives are addressed. First, to obtain a representative model for a NASA generic aircraft at an unsteady condition in the flight envelope and second, to evaluate the techniques involved. To meet these objectives, two different generic aircraft configurations are modeled using both experimental and analytical data. With these results, an initial assessment of the efficiency and quality of the tools and test techniques are evaluated to develop guidance for analytical and experimental approaches to unsteady modeling. I. Nomenclature

Investigation of Reduced-Order Modeling for Aircraft Stability and Control Prediction

“…The recent focus vehicle for the Technologies for Airplane State Awareness subproject has been a Generic T-Tail (GTT), aft twin-engine commuter jet. Considerable effort [8,10,11,43] has been directed toward bringing aerodynamic data from CFD sources into the system identification (SysID) process for constructing dynamic stability derivatives for transport aircraft. The most recent attempt is reported in Refs.…”