Investigation Of Aerodynamic Characteristics And Flight Stability Simulation Of Tailless UAV

Tailless wing flying layout is a series of unmanned aircraft based on stealth properties.Because the layout is designed as a configuration without the vertical and horizontal control surfaces,there are some birth defects of the dynamic characteristics of the body.This paper presents an approach to avoid these defects.And the rudder placed on the winglet is proposed to enhance the lateral stability of the vehicle.This special tailless configuration is a series of aircraft with the same fuselages and the same rudders and wings.The lateral stability of the winglets of different aspect ratios is compared.Firstly,the lift-drag characteristics of the two configurations and the rudder efficiency of control surfaces are obtained by CFD simulation,and the selection of the wing type is completed.At the same time,the unsteady numerical calculation based on rigid dynamic grid technology is carried out to obtain the dynamic characteristics of the aircraft.Secondly,the small aspect ratio aircraft is selected for test verification.Various error collection methods are used to determine the condition that grid meets the requirements for the numerical calculation of the static and dynamic characteristics of the aircraft.The results of unsteady calculation are used to simulate the dynamic derivatives of the aircraft.At the same time,an engineering estimation method for the dynamic derivatives,which is high-efficiency,is proposed.Thirdly,the fuzzy logic modeling is carried out,whose inputs are angle of attack,sideslip angle,and rudder deflection and outputs are all steady aerodynamic parameters of the aircraft.Finally,the simulation based on the outputs verifies the stability of the aircraft in flight.The conclusion is that this configuration is directive and has the practically applied value.