关键词: 浮力不稳定性, 无粘性不稳定性, 粘性不稳定性, 中性曲线, 特征振型

Abstract: The instability in the natural convection boundary layer initiates with the buoyancy eigenmode and develops into non-linear stage with the turbulization of the buoyancy eigenmode. In the mean time, the invisid eigenmode at the inflexion point appears and begins to increase at the outer layer. Experimental results show that the turbulent layer near the maximum velocity point can be detected while the reformed Grashof number G＞100 and after the buoyancy eigenmode crashes down; when G＞170, the invisid eigenmode becomes turbulent and the viscous eigenmode in the high shear layer near the wall appears. All of these characterize the growth and decaying of the instability waves in the natural convection boundary layer with spatial mode.

Key words: buoyancy instability, invisid instability, viscous instability, neutral curve, eigenmode