三角翼动态大迎角气动力特性数值分析研究

Numerical Investigation of Unsteady Aerodynamic Characteristics of Pitching Delta Wings

采用数值计算方法,对三角翼从 0°上仰至 90°的动态流场和气动力特性进行了计算,并对俯仰角速度对三角翼流场和气动力特性的影响进行了计算分析。给出了三角翼纵向动态情况下的气动力系数变化,特别是大迎角横侧力矩系数的变化特征。结果表明,随着机翼俯仰角速度的提高,前缘分离涡破裂位置相对滞后,机翼升力和阻力系数明显增加,机翼抵抗旋涡非对称破裂的能力明显增强。

A numerical investigation of the structure of the vortical flowfield over a delta wing undergoing a pitch-up motion from 0° to 90° is presented. 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 separation vortices. Two cases are considered to investigate the frequency effect on the flowfield structure and aerodynamic loads for the delta wing. As the frequency increases, the location of vortex breakdown delays, and the lift and drag coefficients increase. For lower frequency case, the location of vortex breakdown attains the wing apex early, and the lateral moments are more evident resulting from the earlier occurrence of the asymmetric flowfield over the delta wing at high angles of attack.