Bulletin of the American Physical Society最新文献_第8页

Open questions in turbulent stratified mixing: Do we even know what we do not know? 湍流分层混合中的开放问题:我们知道我们不知道的吗?

Bulletin of the American Physical Society Pub Date : 2019-11-24 DOI: 10.1103/physrevfluids.5.110518

Colm‐cille P. Caulfield

引用次数: 27

Coalescence dynamics of a droplet on a sessile droplet 液滴在无基液滴上的聚结动力学

Bulletin of the American Physical Society Pub Date : 2019-11-23 DOI: 10.1063/1.5129901

Manish Kumar, R. Bhardwaj, K. Sahu

引用次数: 33

Effect of viscosity and density ratios on two drops rising side by side 粘度和密度比对两滴并排上升的影响

Bulletin of the American Physical Society Pub Date : 2019-11-23 DOI: 10.1103/physrevfluids.5.013601

Sivanandan Kavuri, Mounika Balla, M. Tripathi, K. Sahu, R. Govindarajan

{"title":"Effect of viscosity and density ratios on two drops rising side by side","authors":"Sivanandan Kavuri, Mounika Balla, M. Tripathi, K. Sahu, R. Govindarajan","doi":"10.1103/physrevfluids.5.013601","DOIUrl":"https://doi.org/10.1103/physrevfluids.5.013601","url":null,"abstract":"In most of the industrial processes today we might have to deal with bubbly flows. The starting point to this problem is to find the interactions between a pair of bubbles. In this thesis the effect of viscosity and density ratios on a pair of rising bubbles is examined. The ranges of the viscosity and the density ratios are chosen such that they represent pairs of fluids which are commonly used in industries and households. To understand the dynamics of pair of bubbles rising inside quiescent liquid we compared them with the dynamics of a of single bubble rising in a liquid. Tripathi et al. [20] identified five different regimes which describe the dynamics of a rising bubble in a quiescent liquid. The region I corresponds to low inertial regime where an air bubble rises maintaining its azimuthal symmetry and the region III corresponds to high inertial regime where the motion of a rising air bubble is chaotic. In this thesis the effect of the viscosity ratio and the density ratios on two bubbles rising side by side are found in region I and region III corresponding to the rise dynamics of a single bubble. Further to completely analyze the dynamics of pair of bubbles we plotted shapes, trajectories, aspect ratios, velocity contours and voricity of the two-bubbles over a wide range of the viscosity and density ratios(ranging from gas-liquid to liquid-liquid systems).","PeriodicalId":9375,"journal":{"name":"Bulletin of the American Physical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86594020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Viscoelastic flow instabilities in static mixers: Onset and effect on the mixing efficiency 静态混合器的粘弹性流动不稳定性:开始及对混合效率的影响

Bulletin of the American Physical Society Pub Date : 2019-11-23 DOI: 10.1063/5.0038602

S. Migliozzi, L. Mazzei, P. Angeli

{"title":"Viscoelastic flow instabilities in static mixers: Onset and effect on the mixing efficiency","authors":"S. Migliozzi, L. Mazzei, P. Angeli","doi":"10.1063/5.0038602","DOIUrl":"https://doi.org/10.1063/5.0038602","url":null,"abstract":"Elastic instabilities are identified as flow instabilities occurring in the presence of low inertial effects, induced by the combination of strong elastic forces with nonlinearities of the flow. In continuous flow laminar mixing applications, the onset of these instabilities is likely to occur in the window of applied flow rates; therefore, it is important to understand the effects of their onset on the process efficiency. In this work, we investigated experimentally the onset of elastic instabilities in two tubular static mixers with different geometric features, i.e., the Kenics helical mixer and the SMB-R mixer, the latter characterized by a double X-shaped bar geometry. We obtained concentration maps at various mixer lengths by means of planar laser induced fluorescence techniques. To deduce a generalized effect of the fluid elasticity on the mixing patterns, we tested three fluids with different rheological behavior—a Boger fluid and two shear-thinning fluids. For all cases, we observed deviations from the Newtonian benchmark as soon as the Deborah number exceeded unity, even though different transitions occurred as the mean flow rate increased. The effect of the instability on the mixing patterns strongly depended on the different kinematics induced by the two geometries: for the helical mixer, the typical lamellar structure is not recovered and the two liquid streams remain unmixed, while for the SMB-R, the concentration maps are strongly unsteady, showing temporally and spatially chaotic fluctuations of the mass fraction. In both cases, the instabilities worsen the mixing efficiency compared to the Newtonian case.","PeriodicalId":9375,"journal":{"name":"Bulletin of the American Physical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91127054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Rayleigh-B'{e}nard Convection in Liquid Metal under Influence of Vertical Magnetic Fields 垂直磁场影响下液态金属的Rayleigh-B {e}nard对流

Bulletin of the American Physical Society Pub Date : 2019-11-23 DOI: 10.14278/RODARE.232

Felix Schindler, Till Zuerner, T. Vogt, Sven Eckertz, J. Schumacher

引用次数: 0

Direct Simulation of Fluid–Structure Interaction in a Hypersonic Compression-Ramp Flow 高超声速压缩斜流流固耦合直接模拟

Bulletin of the American Physical Society Pub Date : 2019-11-23 DOI: 10.2514/1.J059072

Bryson T. Sullivan, T. Whalen, S. Laurence, D. Bodony

引用次数: 3

Measurements of Photonuclear Reaction Pathways towards Promising Medical Radioisotopes 有前途的医用放射性同位素的光核反应途径的测量

Bulletin of the American Physical Society Pub Date : 2019-11-09 DOI: 10.2172/1830308

Mohammad Ahmed, C. Howell, D. Rotsch, J. Nolen, F. Krishichayan, Noiki Fumnilola Risalah

{"title":"Measurements of Photonuclear Reaction Pathways towards Promising Medical Radioisotopes","authors":"Mohammad Ahmed, C. Howell, D. Rotsch, J. Nolen, F. Krishichayan, Noiki Fumnilola Risalah","doi":"10.2172/1830308","DOIUrl":"https://doi.org/10.2172/1830308","url":null,"abstract":"Radioisotopes play important roles in numerous areas ranging from medical treatments to national security and basic re-search. Some examples include investigations of structures and reactions involving atomic nuclei, Mossbauer spectroscopy, radio- thermoelectric generation, nuclear device detection, and the mitigation of nuclear proliferation. The high speci(cid:12)c activity beta emitters such as 47 Sc, 67 Cu, 77 As, and 186 Re are of extreme interest to the community as they have ideal nuclear properties for medical applications. The present ongoing work is dedicated to develop methodologies for the determination of photonuclear cross sections over multiple energies in a single irradiation and simultaneously determine the feasibility of production of these in-demand radioisotopes using electron linear accelerator. By using activation techniques, cross sectional data is being obtained for these radioisotopes. The present talk will be focused on the technology development for medical radioisotope production using monoenergetic photon beams provided by the HIGS facility at TUNL. Work supported in part by the U.S. DOE Isotope Program","PeriodicalId":9375,"journal":{"name":"Bulletin of the American Physical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90122230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Two Component Electric Field Dynamics of a ns-SDBD Plasma with Sub-Nanosecond Resolution by Femtosecond EFISH 用飞秒鱼研究亚纳秒分辨率ns-SDBD等离子体的双分量电场动力学

Bulletin of the American Physical Society Pub Date : 2019-10-31 DOI: 10.2514/6.2020-1747

Kristofer Meehan, A. Starikovskiy, A. Dogariu, R. Miles

引用次数: 2

Modeling of streamer interaction with dense and rarefied flat gaseous layers 流光与致密稀薄扁平气体层相互作用的模拟

Bulletin of the American Physical Society Pub Date : 2019-10-30 DOI: 10.2514/6.2020-1663

A. Starikovskiy, N. Aleksandrov

引用次数: 0

Electrical Characterization of an Atmospheric Pressure Plasma Jet 大气压等离子体射流的电特性

Bulletin of the American Physical Society Pub Date : 2019-10-29 DOI: 10.3126/jnphyssoc.v5i1.26935

Sushil Kc, D. Subedi, R. Shrestha

引用次数: 3