Vortex Loop Dynamics; a Phenomenological Model for Turbulent Boundary Layer Structure.
Abstract
The results of a combined analytic/experimental study of the unsteady development of three dimensional vortex loops in the vicinity of solid surfaces and under the influence of a crossflow is detailed. It is important to understand the factors which influenced the development of this coherent structure, since it has long been recognized that a three-dimensional convecting stretching vortex loop is a major component of turbulent boundary layer flow. The initial development of this structure is examined by numerically and experimentally studying the temporal and spatial interaction between a two dimensional viscous jet and a viscous crossflow. In the cases considered the crossflow caused the ejected fluid from the jet to be rolled up into a vortex structure which appeared to be similar to the loop-like coherent vortex structure found in turbulent boundary layers. To study the long time development of vortex loops, a combined numeric and experimental approach is again used. These synergistic studies indicate that substantial loop growth occurs only due to the presence of an imposed shear, such as that experienced by the loop within the turbulent boundary layer. This interaction between the loop and the imposed crossflow plays the dominant role in the loop deformation process.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1986
- Accession Number
- ADA177838
Entities
People
- Stephen M. Batill
- Thomas L. Doligalski
Organizations
- University of Notre Dame