Simulating actuator energy demands of an aircraft in flight

This thesis contributes towards the discipline of whole aircraft simula- tion; modelling ight dynamics and airframe systems simultaneously. The objective is to produce estimates of the dynamic power consumption char- acteristics of the primary ight control actuation system when executing manoeuvres. Three technologies are studied; the classic hydraulic actuators and the electromechanical and electro-hydrostatic types that are commonly associated with the more electric aircraft. Models are produced which represent the ight dynamics of an aircraft; these are then combined with low frequency dynamic functional models of the three actuator technologies and ight controllers. The result is a model, capable of faster than real time simulation, which produces estimates of ac- tuator power consumption as the aircraft follows prede ned trajectories. The model is used to quantify the energy consumption as a result of di erent manoeuvre rates when executing banked turns. The result from an actuation system point of view alone is that the lower the turn rate, the lower the overall energy used. The tradeo is that the turn radius becomes larger. The use of the model can be extended to assist with additional design challenges such as actuator design and speci cation. Using methods to size actuators based on stall force and no load speed properties leads to oversizing of the control system. Performing dynamic analyses is usually a combined task of laboratory based actuator test rigs stimulated by input data gathered during ight tests. The model in this work provides a method of generating data for preliminary design; therefore reducing the amount of ight testing required in a design and certi cation programme. The major results discovered using the tools developed in this thesis are that a hydraulically powered aileron uses 4.23% more energy to achieve a turn at a heading rate of 0.03 rad/s compared to a 0.005 rad/s manoeuvre in the same conditions. The electromechanical actuator (EMA) uses 1.67% more and the electrohydrostatic actuator (EHA) uses 1.54% more to achieve the same turns. It implies reduced turn rate turns would have the largest bene t for reducing energy consumption in current hydraulically powered actuation systems, compared to electrical actuators.