带背鳍平板三角翼分离涡流场的显示与测量

对后掠角82.5°的平板三角翼和在其对称面分别加低、高背鳍后的组合体在低速风洞进行了烟粒子/激光片光流场显示与测量实验,实验迎角29°,侧滑角为0°.结果表明:对于单独平板三角翼和加高背鳍组合体,其流场是对称、锥型和稳定的;而加上低高度背鳍后,涡变得非对称、非锥型和不稳定.实验结果直接验证了前人关于细长锥体分离涡的稳定性理论,并给出了旋涡失稳后流场的具体表现特性.

Visualization and measurement study of vortex flow over delta wing with dorsal fins

A smoke/laser-sheet visualization and measurement experimental study was performed on a flat-plate delta wing of 82.5°sweep angle and combinations of the identical delta wing with a low and high dorsal fins respectively, which were mounted vertically in the symmetric incidence plane of the wing. Test was conducted at angles of attack of 29° and 0° sideslip. The test results clearly indicate that the vortices over the wing alone model are conical, symmetric and steady; the vortices become asymmetric and non-conical over the model with the low fin and recover symmetry and conicity over the model with the high fin for the same flow conditions, providing first time experimental evidence of the theoretical predictions and depicting the flow behavior after the onset of the vortex instability.