Yung-Huai Kuo

Steady two-dimensional potential flows involving imbedded supercritical regions adjacent to a body have been calculated, but their existence has not yet been established experimentally. To further experimentation, the question of stability of such flow is examined.

Following the standard procedure, a theoretically possible flow is disturbed at a certain instant, and the behavior of the subsequent disturbance motion is investigated. By means of the transonic approximations, a simple solution valid in the neighborhood of the sonic line has been obtained. This study leads to the conclusion that (1) smooth decelerating transonic flows over bodies at negative curvature are unstable to compression pulses; (2) smooth accelerating transonic flows over any surface are stable; and (3) smooth transonic flows with local supersonic region are unstable.

论二元光滑跨声速流的稳定性

郭永怀

我们已经计算了物面附近有局部超声速区的二元定常势流，但是，实验还未证实这种流动确实能够存在。为了进一步开展实验工作，现在来研究其稳定性问题。

按照通常的步骤，我们在某一时刻先给理论上可能发生的流动以一个小扰动，再来研究该扰动随后发生演化的行为。用跨声速近似，我们得到了在声速线附近有效的简单解。本文的结论是：

(1) 负曲率物体光滑减速跨声速绕流对于压缩脉冲是不稳定的；

(2) 任意形状物体光滑加速跨声速绕流是稳定的；

(3) 具有局部超声速区的光滑跨声速流是不稳定的。

______________________________________________________

原文发表于Journal of the Aeronautical Sciences,1951,18(1)1-6, 见《郭永怀文集》北京：科学出版社出版，pp.313-338, 2009.