In-Trim Flight Investigations of a Conceptual Fluidic Thrust-Vectored Unmanned Tail-Sitter Aircraft

The feasibility of using a stand alone fluidic thrust- vectoring (ftv)system for the purpose of longitudinal trim of an unmanned aerial vehicleis the [ocus of the research presented in this paper. since the fluidic thrustvectoring requires high pressure secondary air to deflect the engine exhaustgases, this research also provides an analytical toolset for the preliminary sizingof a suitable secondary air supply. the study is based on a conceptual modelof a vertical take-off and landing (vtol) tail-sitter type unmanned aerialvehicle in three common phases of flight named as hovering, transition andcruise. a relationship is finally presented between the thrust-vectoring angleand the required secondary mass flow rate.it is found that, just by use of ftv system the aircraft trim is possible.in addition. the mathematical model developed in this study can be used alia preliminary tool for overall performance evaluation of such a conceptualaircraft, especially for sensitivity analysi8 of thrust-vectoring control and findingthe optimum values of the parameter's like centre of gravity and engine location.