The assessment of a rotorcraft simulation model in autorotation by means of flight testing a light gyroplane
The simulation and flight testing of a light gyroplane aircraft is performed obtaining results regarding the flight dynamics attributes of the vehicle. The main aim of the work was to assess the ability of a mathematical model to simulate rotorcraft in the autorotative flight state. Additionally, the results acquired were to enhance the understanding of an aircraft class for which the existing database of knowledge is limited, particularly with regards to its flight mechanics characteristics. An appropriate aircraft configuration file was obtained enabling a platform of simulation results to be generated. Parametric studies were performed primarily focusing on the influence of the vertical centre of gravity position and rotor speed degree of freedom on gyroplane longitudinal stability. A data acquisition system unique in its sophistication for this class of aircraft was developed and installed on board. The software required to drive the system was designed, and rigorous tests verifying the instrumentation functionality were conducted both on ground and in real flight. A flight test programme capable of fulfilling the experimental aims was devised and realised, yielding results both on the steady state flight characteristics of the aircraft and its dynamic response to pilot inputs. Certain trends were established on the properties of gyroplanes by interpreting the results in terms of basic aerodynamic theory, and by comparing them to previous research findings. A comparison of the experimental data to that obtained from the simulation runs, served to fulfil the model validation aim of the work presented. The effect of model and flight discrepancies on the ability of the mathematical model to realistically emulate flight dynamics in autorotation was discussed, and possible suggestions for the reasons of mismatch were presented.