000004687 001__ 4687
000004687 005__ 20141119144545.0
000004687 04107 $$aeng
000004687 046__ $$k2002-06-02
000004687 100__ $$aJackson, P. Ryan
000004687 24500 $$aEFFECTS OF DIFFERENTIAL DIFFUSION ON MIXING EFFICIENCY IN A DIFFUSIVELY-STABLE, TURBULENT FLOW

000004687 24630 $$n15.$$pProceedings of the 15th ASCE Engineering Mechanics Division Conference
000004687 260__ $$bColumbia University in the City of New York
000004687 506__ $$arestricted
000004687 520__ $$2eng$$aLaboratory experiments are used to evaluate the conditions under which differential diffusion exists and its effect on the mixing efficiency. Experiments are conducted using a linearly stratified system, which is stably stratified with both heat and salt to ensure equal Richardson numbers RiT = (NLT/u) and Reynolds numbers ReT = uLT/ν are seen for both scalars as the system is stirred using horizontally oscillating vertical rods. Both the work done on the system and the potential energy change of the system are directly measured to compute the mixing efficiency—defined as the ratio of the potential energy change to the work done. The eddy diffusivities of heat and salt are presented as a function of εa/νN , where εa is a volume and time averaged dissipation. The results of this study suggest that differential diffusion exists below εa/νN = 300 and above a turbulent Richardson number of 0.1. For relatively strong stratification and weak turbulence (RiT > 0.1, εa/νN < 300) the high density ratio experiments have a significant increase in the mixing efficiency over their low density ratio counterparts. These experiments verify that the density ratio can have as large an influence on the mixing efficiency as the stratification strength and the process generating the turbulence.

000004687 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000004687 653__ $$aDifferential diffusion, stratified flows, mixing efficiency

000004687 7112_ $$a15th ASCE Engineering Mechanics Division Conference$$cNew York (US)$$d2002-06-02 / 2002-06-05$$gEM2002
000004687 720__ $$aJackson, P. Ryan$$iRehmann, Chris R.
000004687 8560_ $$ffischerc@itam.cas.cz
000004687 8564_ $$s173664$$uhttps://invenio.itam.cas.cz/record/4687/files/176.pdf$$yOriginal version of the author's contribution as presented on CD, .
000004687 962__ $$r4594
000004687 980__ $$aPAPER