INVARIANCE OF INTERACTIVE-STRUCTURE BETWEEN CONVECTION AND DIFFUSION
对流-扩散相互作用结构的不变性

In this paper three invariant theorems of interactive-structure between convection and diffusion for incompressible laminar shear flow and its ten inferences are presented. The invariance of interactive-structure means that the laminar shear flow and its linearized and nonlinear disturbance fields have the same interactive-structure between convection and diffusion and the same physical scales (including the time, spatial and velocity scales). In illustration of the present theoretical application, we derive a generalized Orr-Sommerfeld (GOS) equation, which takes both non-parallel flow effect as well as time-spatial scale effect into account, and find that GOS equation has two viscous solutions corresponding to the retarded layer and the interaction layer, respectively. Special cases of GOS equation with its two viscous solutions include the classical Orr-Sommerfeld equation and the basic equation of Triple-deck stability theory.