粘流-无粘干扰流动(IF)理论

VISCOUSrINVISCID INTERACTION FLOW THEORY

对不可压缩层流二维干扰流动,本文提出一个干扰流动(IF)理论。IF理论要点为:1)干扰流动沿主流的法向被分为三层即粘性层、干扰层和无粘层,引进了法向动量交换为主导过程的干扰层概念。2)利用力学守恒律、三层匹配关系及文中引进的干扰模型,把三层的空间尺度及惯性-粘性诸力的数置级表示为单参数m的函数,m<1/2·3)导出描述各层流动的控制方程、导出描述全城流动的控制方程为简化Navie-Stokes(SNS)方程。IF理论适用于不存在分离的附着干扰流动以及存在分离的大范围干扰流动,经典边界层(CBL)理论和流动分离局部区域Triple-Deck(TD)理论分别是本文理论在参数m=O和1/4时的两个特例,本文理论容易推广到可压缩、三维及湍流流动。

A theory of viscous-inviscid interaction flow for incompressible, laminar, two-dimensional case is presented in this paper. Main points of this theory are as follows. 1) the interaction flow can be divided into three layers, in the normal direction perpendicular to the main streamwise direction. The three layers are viscous layer, interaction layer and inviscid layer, respectively. A concept of interaction layer where the momentum transferring in the normal direction plays a leading role is introduced. 2) With the use of the laws of mass, the matching relation between three layers and an interaction model which is introduced in this paper, the length scales in the coordinate directions of the three layers and the orders of magnitude of various terms in the Navier-Stokes equations are expressed as the functions of asingle real parameter m which is less than 1/2. 3) The basic equations governingthe flow in each of the three layers as well as the flow in the whole field are deduced. The basic equations governing the whole-field flow is the simplified Navier-Stokes equations. The theory is applicable to the viscous-inviscid interaction flow without separation and also to the separation-reverse flow-reattachment flow region.Por the special cases of m= 0 and 1/4, the theory is reduced to the classical boundarylayer theory and the triple-deck theory of self-induced separation, respectively. The theory can be extended to compressible, three-dimensional flows. It can also be extended to the turbulent flows.