Accession Number : ADA264226


Title :   Laboratory Studies of Gravity Wave/Mean Flow Interactions


Descriptive Note : Annual rept. 15 Nov 91-14 Nov 92,


Corporate Author : NORTHWEST RESEARCH ASSOCIATES INC BELLEVUE WA


Personal Author(s) : Delisi, Donald P


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a264226.pdf


Report Date : 04 Mar 1993


Pagination or Media Count : 32


Abstract : Progress is reported on laboratory measurements of gravity wave/ critical layer interactions. Previous results have been reported for the interactions of single monochromatic waves propagating in a stratified fluid with a vertical velocity shear. The new results presented here are for two monochromatic forcing waves, each propagating with a different phase speed. Thus, the critical layer for each wave is distinct in the vertical. The results for the two-wave case are compared to similar results for the one-wave case. In the one-wave case, only weak overturning appeared in the upper part of the tank for interaction times longer than about 13 minutes, and regular, periodic turbulence was observed in the lower part of the tank. In contrast, in the two- wave case, sustained overturning was observed in the upper part of the tank and packets of turbulence were seen in the lower part of the tank. Velocity profiles are currently being examined to attempt to understand these observed differences. Other improvements in the hardware and software of the facility are also reported, and plans for the coming year are discussed. Gravity wave, Critical layer, Internal wave, Stratification, Shear, Turbulence.


Descriptors :   *TURBULENT FLOW , *FLOW VISUALIZATION , *GRAVITY WAVES , VELOCITY , SOFTWARE ENGINEERING , MEASUREMENT , SHEAR STRESSES , HYDRAULIC MODELS , FLUID FLOW , INTERNAL WAVES , STRATIFICATION , PACKETS , INTERACTIONS , LAYERS , TURBULENCE


Subject Categories : Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE