Abstract: A new aerodynamic configuration of unmanned aerial vehicle (UAV) with variable forward-swept wing was investigated, under which the forward-swept angle can be varied to obtain optimal aerodynamic characteristics during low, subsonic, tansonic and supersonic speeds. The basic figuration was designed according to the guidelines and blended wingbody technique, and aerodynamic characteristics of five different configurations were investigated by numerical method based on 3D Navier-Stokes equations. The results show four aspects as follows: (1) when cruising at Ma=0.6, the unswept-wing configuration with wingtip oiltank has maximal lift-drag ratio 14.55, while the delta-wing configuration is only 8.29; (2) when maneuvering at Ma=0.4, the 45° forward-swept-wing configuration has 38° stalling angle and maximal lift coefficient 2.455, which improves by 4.9% than the unswept-wing configuration; (3) when dashing at Ma=1.5, the delta-wing configuration has minimal zero-lift drag coefficient which minishes by 14.4% as compared with the unsweptwing configuration with wingtip oiltank, and the maximal lift-drag ratio improves by 34.6%; (4) the pithcing moment characteristics under all caculated states are fine. Reseach results of this article can validate that the new aerodynamic configuration is reasonable and advanced, and can also provide references for high perfomance UAV design.

Key words: unmanned aerial vehicle, variable forward-swept wing, aerodynamic configuration, blended wing-body, numerical simulation