Accession Number : ADA290272

Title :   Molecular Mixing in Shear Layers Forced by 2-D and 3-D Disturbances.

Descriptive Note : Final technical rept.,

Corporate Author : MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Koochesfahani, Manoochehr M.

PDF Url : ADA290272

Report Date : 26 OCT 1994

Pagination or Media Count : 153

Abstract : Experiments on 2-D forcing of shear layers were completed. Analysis of data from two different forcing techniques have revealed that much of the global aspects of the scalar mixing field appear to exhibit a universal behavior in terms of the non-dimensional downstream distance x * = x Xf/ Uc where X = (U1 -U2)/(U1 +U2) and Uc = (U1 +U2)/2. This universal behavior suggests that the total amount of mixing per unit width of the layer is enhanced in regions where x* > 1.5. Work on 3-D forcing and combined 2-D/3-D forcing has lead to new findings. Results show that high amplitude 2-D forcing of a low Reynolds number wake can lead to a dramatic increase in mixing due to 3-D interaction of the vorticity field with the test section side walls. The possible application of this finding to mixing enhancement at higher Reynolds numbers is being investigated. Experiments on shear layers forced by a localized 3-D perturbation at the splitter plate along with 2-D forcing have shown that it is possible to significantly alter not only the predominant mixed-fluid composition but also the actual pdf structure (e.g. non-marching and marching behavior). Preliminary results suggest that the behavior of the span-averaged total mixing is similar to the case of purely 2-D forcing. (AN)

Descriptors :   *TURBULENT FLOW, *WAKE, *JET MIXING FLOW, SHEAR PROPERTIES, EXPERIMENTAL DATA, OPTIMIZATION, LASER INDUCED FLUORESCENCE, COMPARISON, BOUNDARY LAYER, VORTICES, COMPUTATIONAL FLUID DYNAMICS, FLOW VISUALIZATION, PROBABILITY DENSITY FUNCTIONS, FLOW FIELDS, PERTURBATIONS, SCALAR FUNCTIONS, TWO DIMENSIONAL FLOW, FREE STREAM, REYNOLDS NUMBER, GAS SURFACE INTERACTIONS, THREE DIMENSIONAL FLOW.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE