Research On Flying Wing Aircraft’s Aerodynamics, Flight Control And Flight Quality At Conceptual Designing Phase

The stability and control system design always last through the whole process of the aircraftdesign. Sometimes they even last longer than the aircraft design. After the relaxed static stabilitytechnology is used by novel concepts such as flying wing configuration (FWC), the designing of thestability and control becomes more and more important. If some unexpected stability problems are notfound until the later designing phases, the cost spent on redesigning will be much more. So, predictingthe stability and control characteristics of a new configuration at the conceptual phase tends to beextremely important.In this paper, a tailless flying wing model aircraft is taken as the example. Firstly, by buildingfour models, this essay finds an approach on how to quickly and precisely estimate the aerodynamiccharacteristics of the flying wing aircraft using the aerodynamic evaluating software Datcom. Then，the stable and dynamic features of the pure aircraft are analysis to decide whether the stabilityaugmentation is needed. In order to assess the efficiency of the control effectors, several critical flightconditions are selected to assess the requirements of the three directions’ control efficiencies.Eigenstructure assignment based on state feedback is chosen to design the stability augmentationsystem to resolve the problem that the longitudinal and directional stability are not enough to assurethe flight safety or to meet the requirements of the flight quality criteria. At last, the lateral flightquality of high-order systems is studied by low-order equivalent method.The process and the methods in this paper have certain guiding significance to the conceptualdesign of FWC aircrafts and engineers.