On the Oscillations of Free Convection Boundary Layers
Abstract
An extensive, definitive study was conducted of forced oscillations of the free convection boundary layer. Various disturbances were introduced at different positions in the laminar boundary layer of a vertical flat plate, heated to approximately 40 deg F above ambient temperature. The resulting wave motion was studied from initial formation to the onset of turbulence. Wave length, amplitude, speed and frequency were found to vary with distance from the plate surface, as well as with the distance from the plate's leading edge. No apparent relation existed among the various parameters which could be applied to the general flow conditions. No correlation between actual wave frequency and disturbance pulse frequency was found to exist. Empirical relations developed in a previous study (AD0140652) for a defined natural boundary layer frequency and wave length with a Grashof-Prandtl Number product were found to be applicable only to the conditions under which they were developed. Therefore, it was concluded that at the present time there is no known relation or empirical equation which will predict the nature of oscillations of general boundary layer flow.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1959
- Accession Number
- AD0228295
Entities
People
- Harold E. Gartrell
Organizations
- Air Force Institute of Technology