{"id":2901,"date":"2016-05-23T17:06:53","date_gmt":"2016-05-23T17:06:53","guid":{"rendered":""},"modified":"2016-05-23T17:20:38","modified_gmt":"2016-05-23T17:20:38","slug":"large-eddy-simulation-and-parameterization-of-buoyant-plume-dynamics-in-stratified-flow","status":"publish","type":"post","link":"https:\/\/www.marine.usf.edu\/c-image\/large-eddy-simulation-and-parameterization-of-buoyant-plume-dynamics-in-stratified-flow\/","title":{"rendered":"Large-eddy simulation and parameterization of buoyant plume dynamics in stratified flow"},"content":{"rendered":"<p>Abstract:<\/p>\n<p>Characteristics of laboratory-scale bubble-driven buoyant plumes in a stably stratified\u00a0quiescent fluid are studied using large-eddy simulation (LES). As a bubble plume\u00a0entrains stratified ambient water, its net buoyancy decreases due to the increasing\u00a0density difference between the entrained and ambient fluids. A large fraction of\u00a0the entrained fluid eventually detrains and falls along an annular outer plume from\u00a0a height of maximum rise (peel height) to a neutral buoyancy level (trap height),\u00a0during which less buoyant scalars (e.g. small droplets) are trapped and dispersed\u00a0horizontally, forming quasi-horizontal intrusion layers. The inner\/outer double-plume\u00a0structure and the peel\/intrusion process are found to be more distinct for cases with\u00a0small bubble rise velocity, while weak and unstable when the slip velocity is large.\u00a0LES results are averaged to generate distributions of mean velocity and turbulent\u00a0fluxes. These distributions provide data for assessing the performance of previously\u00a0developed closures used in one-dimensional integral plume models. In particular,\u00a0the various LES cases considered in this study yield consistent behaviour for the\u00a0entrainment coefficients for various plume cases. Furthermore, a new continuous\u00a0peeling model is derived based on the insights obtained from LES results. Comparing\u00a0to previous peeling models, the new model behaves in a more self-consistent manner,\u00a0and it is expected to provide more reliable performance when applied in integral\u00a0plume models.<\/p>\n<p>Source: <a href=\"https:\/\/www.researchgate.net\/publication\/300002141_Large-eddy_simulation_and_parameterization_of_buoyant_plume_dynamics_in_stratified_flow\" target=\"_blank\">Yang, D., Chen, B., Socolofsky, S., Chamecki, M., Meneveau, C., \u201cLarge-eddy simulation and parameterization of buoyant plume dynamics in stratified flow,\u201d J. Fluid Mech. (2016), vol. 794, pp. 798\u2013833<\/a><\/p>\n<p>\u00a0<\/p>\n<figure style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" style=\"display: block; margin-left: auto; margin-right: auto;\" src=\"https:\/\/www.marine.usf.edu\/c-image\/wp-content\/uploads\/2019\/09\/YangPlumeTurbulence.JPG\" alt=\"\" width=\"747\" height=\"819\" \/><figcaption>Fig 2. &#8211; Instantaneous velocity and scalar fields for case WR6 at t = 90 s: (a) air concentration Ceb (kg m\u22123); (b) dye concentration Cedye (kg m\u22123); (c) vertical velocity we (m s\u22121); and (d) density \u03c1e (kg m\u22123). Here the (x,z)-plane across the centre of the plume source is shown. The averaged peel and trap heights from the laboratory measurement (Seol et al. 2009) are indicated in (b) by the dashed and dash-dot lines, respectively<\/figcaption><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Abstract: Characteristics of laboratory-scale bubble-driven buoyant plumes in a stably stratified\u00a0quiescent fluid are studied using large-eddy simulation (LES). As a bubble plume\u00a0entrains stratified ambient water, its net buoyancy decreases due to the increasing\u00a0density difference between the entrained and ambient fluids.&hellip;<\/p>\n","protected":false},"author":0,"featured_media":2902,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[186],"tags":[],"class_list":["post-2901","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-task-1-publications","entry","has-media"],"_links":{"self":[{"href":"https:\/\/www.marine.usf.edu\/c-image\/wp-json\/wp\/v2\/posts\/2901","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.marine.usf.edu\/c-image\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.marine.usf.edu\/c-image\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/www.marine.usf.edu\/c-image\/wp-json\/wp\/v2\/comments?post=2901"}],"version-history":[{"count":0,"href":"https:\/\/www.marine.usf.edu\/c-image\/wp-json\/wp\/v2\/posts\/2901\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.marine.usf.edu\/c-image\/wp-json\/wp\/v2\/media\/2902"}],"wp:attachment":[{"href":"https:\/\/www.marine.usf.edu\/c-image\/wp-json\/wp\/v2\/media?parent=2901"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.marine.usf.edu\/c-image\/wp-json\/wp\/v2\/categories?post=2901"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.marine.usf.edu\/c-image\/wp-json\/wp\/v2\/tags?post=2901"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}