LAMINAR FLOW OF A STABLY STRATIFIED FLUID PAST A FLAT PLATE.
Abstract
Laminar flow of a stably stratified fluid with uniform upstream velocity and density gradient past a flat plate is investigated experimentally and theoretically. In the experimental study, the flat plate, parallel to the direction of motion, is towed horizontally at various constant speeds in a tank of stratified salt water at various density gradients. The density before each run is measured with a single electrode conductivity probe. The horizontal velocity in front of, above, and behind the flat plate are measured with a flow visualization technique. One of the striking phenomena is the strong upstream influence (the upstream wake) of an obstacle in a flow of stably stratified fluid when the gravity effect is comparable to, or more than the inertial effect. The velocity profiles of the upstream wake and boundary layer above the flat plate are wavy and found to be strongly governed by the ratio of Reynolds number Re to Richardson number Ri. The problem is also analyzed theoretically with Boussinesq's approximation and two-parameter asymptotic expansions for the far and near fields. The solution of the far-field first-order expansion is compared with the measured upstream wake. The near-field zeroth order solution (boundary layer solution) is compared with measurements above the plate. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1967
- Accession Number
- AD0663664
Entities
Organizations
- Boeing