Accession Number : AD0663664

Title :   LAMINAR FLOW OF A STABLY STRATIFIED FLUID PAST A FLAT PLATE.

Corporate Author : BOEING SCIENTIFIC RESEARCH LABS SEATTLE WASH FLIGHT SCIENCES LAB

Report Date : SEP 1967

Pagination or Media Count : 84

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)

Descriptors :   (*LAMINAR FLOW, FLOW FIELDS), STABILITY, TOWED BODIES, FLAT PLATE MODELS, DENSITY, FLOW VISUALIZATION, WAKE, BOUNDARY LAYER, ONE DIMENSIONAL FLOW, THEORY, EQUATIONS OF MOTION

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE