三角翼大迎角流场结构和气动力特性的数值分析研究

采用数值计算方法对亚音速三角翼纵向及带有小侧滑情况下的流场结构和气动力特性进行了计算。文中给出了三角翼大迎角纵向情况下气动力、机翼前缘分离涡轴线位置和旋涡破裂位置随迎角的变化规律，以及带有横侧小扰动和小侧滑情况下流场结构的非对称性对气动力的影响。计算结果表明与实验结果符合较好。

Numerical Inversigation of Field Structure and Aerodynamic Characteristics of Delta Wings at High Angles of Attack

A numerical investigation of the structure of the vortical flowfield over delta wings at high angles of attack in longitudinal and with small sideslip angle is presented here. Three-dimensional Navier-Strokes numerical simulations are carried out to predict the complex leeward-side flowfield characteristics that are dominated by the effect of the breakdown of the leading-edge vortices. The methods for analyzing the flowfield structure quantitatively are given by using flowfiedld data from the computational results. Besides, the influence of the leading-edge vortices of the aerodynamic coefficients and flight stabilities are researched in the paper. From this work one can find that: (1) In the region before the vortex breakdown, the vortex axes are approximated as being straight line. As the angle of attack increases, the vortex axes are closer to the root chord, and far away from the wing surface; (2) The occurrence of the leading-edge vortex breakdown results in the instability of lateral motion for delta wings under static conditions, and the lateral moment diverges after a small lateral interference occure. However, after a critical angle of attack is reached, the vortices burst completely at the wing apex, and the instability resulting from the vortex breakdown disappears.