低背鳍对细长平板三角翼分离涡稳定性影响的研究

对细长锥体分离涡稳定性判据进行了介绍，并应用该判据对细长体平板三角翼和加上两个不同高度背鳍组合体分离涡流场的稳定性进行了分析。为了验证理论分析的有效性，并观察气动力随迎角的变化，根据理论分析模型设计了实验模型，并在低速风洞进行了六分量天平测力实验，三角翼后掠角为82．5°，实验迎角范围12°～32°，侧滑角范围-10°～＋10°，实验雷诺数1．66×106。实验结果表明：在翼面上发生旋涡破裂前，单独细长平板三角翼的横向力／力矩在实验迎角范围内始终为零；加了两个不同高度的背鳍后，在一定迎角下，三角翼的横向力／力矩变得不为零。理论分析结果和实验结果在定性上吻合得很好，初步验证了有关文献关于细长锥体分离涡的稳定性理论。

Effects of low dorsal fin on the stability of vortex flow over slender delta wing

A vortex stability theory for slender conical bodies which was proposed by the pro- fessors of NWPU was reviewed and used to analyze the asymmetric vortices characteristics of a flat-plate delta wing and its combinations. To verify the validity of the theoretical predictions and show the force development versus angle of attack, a wind tunnel test was conducted on a flat- plate delta wing of 82.5 degrees sweep angle and its combinations using a six-component internal strain-gage balance. The angles of attack is at 12°-32° and sideslip within ±10°. Two fins of dif- ferent heights were tested. The ratios of the local fin height to the local wing semi-gpan were 0. 3 and 0.6 respectively. The Reynolds number is 1.66 million. The measurement of the aerodynamic forces and moments clearly indicates that no lateral force occurs over wing-alone model at lower angles, but a steady force-asymmetry occurs over the wing-fin models at certain angles. The experimental results and the theoretical results are in good agreement qualitatively, it provides force measurement evidence of the validity of the vortex stability theory preliminarily.