CALCULATIONS OF UNSTEADY TURBULENT BOUNDARY LAYERS WITH FLOW REVERSAL

The present studies relate to incompressible time-dependent flow over a two-dimensional surface which is flat or of large radius. The paper reports the results of a series of computational experiments aimed at studying the characteristics of time-dependent turbulent boundary layers with embedded reversed-flow regions. A calculation method, developed earlier by the authors and their co-workers, was extended to boundary layers with reversed flows for this purpose. The calculations were performed for an idealized family of external velocity distributions, and covered a range of degress of unsteadiness. The results confirmed those of previous studies in demonstrating that the point of flow reversal is nonsingular in a time-dependent boundary layer. However, a singularity was observed to develop downstream of reversal, under certain conditions, accompanied by the breakdown of the boundary-layer approximations.

• Corporate Authors:

  National Aeronautics and Space Administration

  400 Maryland Avenue, SW
  Washington, DC  United States  20546
• Authors:
  • Nash, J F
  • Patel, V C
• Publication Date: 1975-5

Media Info

• Features: References;
• Pagination: 46 p.

Subject/Index Terms

• TRT Terms: Boundary layer; Boundary layer flow; Boundary layer separation; Turbulence; Turbulent boundary layer; Unsteady flow
• Subject Areas: Design; Marine Transportation;

Filing Info

• Accession Number: 00127015
• Record Type: Publication
• Source Agency: Engineering Index
• Report/Paper Numbers: CR-2546 Contra Rpt
• Files: TRIS
• Created Date: Nov 5 1975 12:00AM