Air Flow in the Boundary Layer of an Elliptic Cylinder,
Abstract
The boundary layer of an elliptic cylinder of major and minor axes 11.78 and 3.98 inches, respectively, was investigated in an air stream in which the turbulence could be varied. Conditions were arranged so that the flow was two-dimensional with the major axis of the ellipse parallel to the undisturbed stream. Speed distributions across the boundary layer were determined with a hot-wire anemometer at a number of positions about the surface for the lowest and highest intensities of turbulence, with the air speed in both cases sufficiently high to produce a turbulent boundary layer over the downstream part of the surface. The magnitude and the frequency of the speed fluctuations in the boundary layer were also measured by the use of the conventional type of hot-wire turbulence apparatus. Stream turbulence was found to affect both the nature of transition from to turbulent flow in the layer and the position on the surface at which transition occurred. Transition was then investigated in detail with stream turbulence of several different scales and intensities. It was found that the position of transition could be expressed as a function of the intensity divided by the fifth root of the scale. (KAR) P.5
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1939
- Accession Number
- ADA297391
Entities
People
- G. B. Schubauer
Organizations
- National Institute of Standards and Technology