Efficient Global Aerodynamic Modeling from Flight Data

Abstract

A method for identifying global aerodynamic models from flight data in an efficient manner is explained and demonstrated. A novel experiment design technique was used to obtain dynamic flight data over a range of flight conditions with a single flight maneuver. Multivariate polynomials and polynomial splines were used with orthogonalization techniques and statistical modeling metrics to synthesize global nonlinear aerodynamic models directly and completely from flight data alone. Simulation data and flight data from a subscale twin-engine jet transport aircraft were used to demonstrate the techniques. Results showed that global multivariate nonlinear aerodynamic dependencies could be accurately identified using flight data from a single maneuver. Flight-derived global aerodynamic model structures, model parameter estimates, and associated uncertainties were provided for all six nondimensional force and moment coefficients for the test aircraft. These models were combined with a propulsion model identified from engine ground test data to produce a high-fidelity nonlinear flight simulation very efficiently. Prediction testing using a multi-axis maneuver showed that the identified global model accurately predicted aircraft responses.

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“…A recent paper by Morelli 5 in 2012 produced global aerodynamic models for GTM using flight test data. The results were obtained using automated perturbation inputs and were presented over a large range of angle of attack.…”

Inclusion of the D-optimality in multisine manoeuvre design for aircraft parameter estimation

“…This assignment provides orthogonality in the frequency domain as distinct spectral lines form the frequency content of each input. In the time domain, the mutual orthogonality is achieved due to orthogonality properties of the sine function (Morelli, 2012). It is practicable to omit the first harmonic in this assignment in order to optimize the cost function effectively.…”

“…The multisine input is an excitation that is composed of summed harmonic sinusoids with individual amplitudes A k and phase shifts φ k (Morelli, 2012) …”

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