Search

A method based on unstructured overset grid and global sub-iteration is developed, which is used to investigate the virtual flight of a vehicle with closed-loop control by synchronously simulating the coupled aerodynamics and flight dynamics. A static instable hypersonic configuration is pulled up with an increasing attack angle and then trimmed at a certain attack angle according to the designed control law, which is performed by the elevator deflection. The numerical virtual flight presents such integrative evolvement of unsteady flow, rigid body movement and aerodynamic control surfaces vividly. The numerical virtual flight agrees well with the traditional flight simulation based on aerodynamic database in terms of control effects, while there exits some difference during the whole process. [ABSTRACT FROM AUTHOR]

In order to explore the methods of morphing aircraft variable-sweep and their aerodynamic characteristics, numerical simulation of the flow fields of a rotating variable-sweep wing-body and a shearing variable-sweep wing-body was conducted, and the aerodynamic characteristics and its mechanism were analyzed. Numerical simulation method of viscous compressible flow and hybrid grid of prism-hexahedron were used. The results demonstrate that: shearing variable-sweep has better characteristics than rotating variable-sweep in that the former has better lift-to-drag ratio and drag when flying at a speed in the range from M∞, 0.3 to M∞ 0.8, and the main reason is distinct flow field structure caused by the different variable-sweep methods. [ABSTRACT FROM AUTHOR]

There are many fundamental problems in the process of morphing of aircraft with large-scale shape change. In order to explore these problems, this paper constructed a research platform and conducted an experimental study. Based on computation of the aerodynamic characteristics of "rotating variable-sweep" and "shearing variable sweep", a variable sweep style of large-scale shearing which has relatively higher aerodynamic efficiency was designed; ex-periment model based on controllable morphing structure and continuous morphing method was constructed; and the wind tunnel experiment was conducted. The results demonstrate that: the skin, structure, actuation and control of this variable-sweep morphing aircraft with outboard wing section large-scale shearing are suitable for aerodynamic research; the quasi-steady aerodynamic characteristics curve show big aerodynamic benefit of variable sweep; the unsteady aerodynamic characteristics curve exhibit hysteresis circle, and the reasons may be wing additional velocity effect and flow-field structure hysteresis effect. [ABSTRACT FROM AUTHOR]