Mathematical Model of the AgustaWestland AW-109-k2 Helicopter: Numerical Simulation and Validation on Real Flight Data

The use of model-based approaches in aerospace engineering has become increasingly widespread in recent years, as it enables cost reductions in design and improvements in safety. This technique is mainly applied during the preliminary design phase to test different configurations and identify those that meet the system requirements. Furthermore, developing a mathematical model proves particularly useful during aircraft refurbishment or configuration modifications, as changes in system behavior and control characteristics can be easily predicted and evaluated. This is precisely the objective of the present master’s thesis. This work was carried out in collaboration with TPS Aerospace Engineering Srl, a leading company in the aerospace sector specializing in the design and certification of aeronautical products and components. The project is part of a continuous thesis program: the implemented models are derived from a previous study conducted on the AgustaWestland AW109K2, a lightweight, twin-engine, eight-seat multipurpose helicopter designed and manufactured by the Italian rotorcraft company Agusta. The main objective of this thesis is to verify and validate the helicopter model through real flight data, in order to develop an offline simulator entirely implemented in MATLAB. The work is organized into three main sections: 1.??Model implementation and verification: the existing submodules of the model have been thoroughly reviewed and updated. Additional features have also been implemented, such as command mapping, engine power calculation, and linear model formulation. 2.??Trim evaluation: starting from an initial set of guessed parameters — namely, control inputs, attitude, and roll angles — the nonlinear state equations were solved iteratively. Once the state vector norm reached an infinitesimal value (10⁻¹⁵), the trim condition was identified. Trim solutions were computed as a function of airspeed and altitude to explore the entire flight envelope. 3.??Model validation through flight data: the results obtained were compared against flight test data, and the discrepancies between corresponding values were analyzed. The results show good consistency with theoretical expectations. The trends of the parameters obtained from the trim analysis exhibit close agreement with those reported in the literature. Minor discrepancies are observed in the lateral plane, particularly in the lateral cyclic control. Regarding engine power requirements, deviations from flight test data are generally within 5–7%, with a few points in the flight envelope showing larger differences — likely due to initial test conditions not fully consistent with those assumed in the model.