Laminar Incompressible Leading and Trailing Edge Flows and the Near Wake Rear Stagnation Point

摘要

The paper investigates the behavior of a viscous incompressible fluid in the vicinity of various two-dimensional separation and stagnation points. Locally valid series solutions to the Navier Stokes vorticity equation are developed to study the pressure-viscous force balance in the neighborhood of the singularity and the transition to the flow region where inertial effects are important. Solutions are presented for an arbitrary symmetric leading or trailing edge except for an arbitrary constant that depends on the wall shear. The solution for the near wake rear stagnation point shows that the wake cannot close in an arbitrary manner, but that the asymptotic direction of the dividing streamline prior to stagnation is a single valued function of the ratio of the velocity on the dividing streamline to that on the wake centerline. The blunt based trailing edge is examined from two viewpoints. One is analogous to Goldstein's development for the flat plate trailing edge in that it assumes a Blasius profile at separation. The other is a parametric study to explore the effect of upstream influence on the point of separation and the initial shape of the dividing streamline. (Author)