Development of High-Fidelity Saab 340B Aerodynamic Model

Accurate aerodynamic characteristics are key components for high-fidelity modelling and simulation. Modern CFD and wind tunnel testing can generate the aerodynamic database, but their accuracy is less accurate compared to those generated through flight tests. This paper applies system identification methods to extract the aerodynamic parameters of Saab 340B aircraft in the time domain from the flight test data. The flight tests are carried out using the Saab 340B aircraft using different excitations on the control surfaces. The flight test data is collected in predefined trim points. Thrust forces and moments are obtained using the propeller efficiency map obtained from the manufacturer. The equation and output error methods are employed to analyze flight test data to estimate aerodynamic parameters in the time domain. The equation-error method is used firstly to identify aerodynamic parameters, and the results are then utilized as a starting point in the output-error process for fine-tuning. The validation of the resulting model is accomplished by comparing the measured flight data to the model’s predictions for identical control inputs, as specified by the Federal Aviation Administration (FAA). The key contribution of this study is the development of a systematic approach to identifying the aerodynamic characteristics of a Saab 340B aircraft using flight test data from the UK’s National Flying Laboratory Centre. The identified aerodynamic parameters can be used for high-fidelity simulation in future research purposes, for example, the development of flight control laws and integration with novel powertrain systems.