{"title":"Particle-Laden Turbulence: Progress and Perspectives","authors":"L. Brandt, F. Coletti","doi":"10.1146/annurev-fluid-030121-021103","DOIUrl":"https://doi.org/10.1146/annurev-fluid-030121-021103","url":null,"abstract":"This review is motivated by the fast progress in our understanding of the physics of particle-laden turbulence in the last decade, partly due to the tremendous advances of measurement and simulation capabilities. The focus is on spherical particles in homogeneous and canonical wall-bounded flows. The analysis of recent data indicates that conclusions drawn in zero gravity should not be extrapolated outside of this condition, and that the particle response time alone cannot completely define the dynamics of finite-size particles. Several breakthroughs have been reported, mostly separately, on the dynamics and turbulence modifications of small inertial particles in dilute conditions and of large weakly buoyant spheres. Measurements at higher concentrations, simulations fully resolving smaller particles, and theoretical tools accounting for both phases are needed to bridge this gap and allow for the exploration of the fluid dynamics of suspensions, from laminar rheology and granular media to particulate turbulence. Expected final online publication date for the Annual Review of Fluid Mechanics, Volume 54 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":50754,"journal":{"name":"Annual Review of Fluid Mechanics","volume":null,"pages":null},"PeriodicalIF":27.7,"publicationDate":"2021-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46518813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Rotating Horizontal Convection","authors":"B. Gayen, R. W. Griffiths","doi":"10.1146/annurev-fluid-030121-115729","DOIUrl":"https://doi.org/10.1146/annurev-fluid-030121-115729","url":null,"abstract":"Global differences of temperature and buoyancy flux at the ocean surface are responsible for small-scale convection at high latitudes, global overturning, and the top-to-bottom density difference in the oceans. With planetary rotation the convection also contributes to the large-scale horizontal, geostrophic circulation, and it crucially involves a 3D linkage between the geostrophic circulation and vertical overturning. The governing dynamics of such a surface-forced convective flow are fundamentally different from Rayleigh–Bénard convection, and the role of buoyancy forcing in the oceans is poorly understood. Geostrophic balance adds to the constraints on transport in horizontal convection, as illustrated by experiments, theoretical scaling, and turbulence-resolving simulations for closed (mid-latitude) basins and an annulus or reentrant zonal (circumpolar) channel. In these geometries, buoyancy drives either horizontal mid-latitude gyre recirculations or a strong Antarctic Circumpolar Current, respectively, in addition to overturning. At large Rayleigh numbers the release of available potential energy by convection leads to turbulent mixing with a mixing efficiency approaching unity. Turbulence-resolving models are also revealing the relative roles of wind stress and buoyancy when there is mixed forcing, and in future work they need to include the effects of turbulent mixing due to energy input from tides. Expected final online publication date for the Annual Review of Fluid Mechanics, Volume 54 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":50754,"journal":{"name":"Annual Review of Fluid Mechanics","volume":null,"pages":null},"PeriodicalIF":27.7,"publicationDate":"2021-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46893529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Drop Impact Dynamics: Impact Force and Stress Distributions","authors":"Xiang Cheng, Ting-Pi Sun, L. Gordillo","doi":"10.1146/annurev-fluid-030321-103941","DOIUrl":"https://doi.org/10.1146/annurev-fluid-030321-103941","url":null,"abstract":"Dynamic variables of drop impact such as force, drag, pressure, and stress distributions are key to understanding a wide range of natural and industrial processes. While the study of drop impact kinematics has been in constant progress for decades thanks to high-speed photography and computational fluid dynamics, research on drop impact dynamics has only peaked in the last 10 years. Here, we review how recent coordinated efforts of experiments, simulations, and theories have led to new insights on drop impact dynamics. Particularly, we consider the temporal evolution of the impact force in the early- and late-impact regimes, as well as spatiotemporal features of the pressure and shear-stress distributions on solid surfaces. We also discuss other factors, including the presence of water layers, air cushioning, and nonspherical drop geometry, and briefly review granular impact cratering by liquid drops as an example demonstrating the distinct consequences of the stress distributions of drop impact. Expected final online publication date for the Annual Review of Fluid Mechanics, Volume 54 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":50754,"journal":{"name":"Annual Review of Fluid Mechanics","volume":null,"pages":null},"PeriodicalIF":27.7,"publicationDate":"2021-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43762275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Muller, D. Yang, G. Craig, T. Cronin, B. Fildier, J. Haerter, C. Hohenegger, B. Mapes, D. Randall, S. Shamekh, S. Sherwood
{"title":"Spontaneous Aggregation of Convective Storms","authors":"C. Muller, D. Yang, G. Craig, T. Cronin, B. Fildier, J. Haerter, C. Hohenegger, B. Mapes, D. Randall, S. Shamekh, S. Sherwood","doi":"10.1146/annurev-fluid-022421-011319","DOIUrl":"https://doi.org/10.1146/annurev-fluid-022421-011319","url":null,"abstract":"Idealized simulations of the tropical atmosphere have predicted that clouds can spontaneously clump together in space, despite perfectly homogeneous settings. This phenomenon has been called self-aggregation, and it results in a state where a moist cloudy region with intense deep convective storms is surrounded by extremely dry subsiding air devoid of deep clouds. We review here the main findings from theoretical work and idealized models of this phenomenon, highlighting the physical processes believed to play a key role in convective self-aggregation. We also review the growing literature on the importance and implications of this phenomenon for the tropical atmosphere, notably, for the hydrological cycle and for precipitation extremes, in our current and in a warming climate. Expected final online publication date for the Annual Review of Fluid Mechanics, Volume 54 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":50754,"journal":{"name":"Annual Review of Fluid Mechanics","volume":null,"pages":null},"PeriodicalIF":27.7,"publicationDate":"2021-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46545809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Flow and Drop Transport Along Liquid-Infused Surfaces","authors":"S. Hardt, G. McHale","doi":"10.1146/annurev-fluid-030121-113156","DOIUrl":"https://doi.org/10.1146/annurev-fluid-030121-113156","url":null,"abstract":"Liquid-infused surfaces (LISs) are composite solid–liquid surfaces with remarkable features such as liquid repellency, self-healing, and the suppression of fouling. This review focuses on the fluid mechanics on LISs, that is, the interaction of surfaces with a flow field and the behavior of drops on such surfaces. LISs can be characterized by an effective slip length that is closely related to their drag reduction property, which makes them suitable for several applications, especially for turbulent flows. Drag reduction, however, is compromised by failure mechanisms such as the drainage of lubricant from surface textures. The flow field can also sculpt the lubricant layer in a coupled self-organization process. For drops, the lubricant reduces drop pinning and increases drop mobility, but also results in a wetting ridge and the associated concept of an apparent contact angle. Design of LIS wettability and topography can induce low-friction drop motion, and drops can dynamically shape the lubricant ridges and film thickness. Expected final online publication date for the Annual Review of Fluid Mechanics, Volume 54 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":50754,"journal":{"name":"Annual Review of Fluid Mechanics","volume":null,"pages":null},"PeriodicalIF":27.7,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47737538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Experiments in Surface Gravity–Capillary Wave Turbulence","authors":"E. Falcon, N. Mordant","doi":"10.1146/annurev-fluid-021021-102043","DOIUrl":"https://doi.org/10.1146/annurev-fluid-021021-102043","url":null,"abstract":"The last decade has seen a significant increase in the number of studies devoted to wave turbulence. Many deal with water waves, as modeling of ocean waves has historically motivated the development of weak turbulence theory, which addresses the dynamics of a random ensemble of weakly nonlinear waves in interaction. Recent advances in experiments have shown that this theoretical picture is too idealized to capture experimental observations. While gravity dominates much of the oceanic spectrum, waves observed in the laboratory are in fact gravity–capillary waves, due to the restricted size of wave basins. This richer physics induces many interleaved physical effects far beyond the theoretical framework, notably in the vicinity of the gravity–capillary crossover. These include dissipation, finite–system size effects, and finite nonlinearity effects. Simultaneous space-and-time-resolved techniques, now available, open the way for a much more advanced analysis of these effects. Expected final online publication date for the Annual Review of Fluid Mechanics, Volume 54 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":50754,"journal":{"name":"Annual Review of Fluid Mechanics","volume":null,"pages":null},"PeriodicalIF":27.7,"publicationDate":"2021-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46164465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Predicting the Drag of Rough Surfaces","authors":"D. Chung, N. Hutchins, M. Schultz, K. Flack","doi":"10.1146/annurev-fluid-062520-115127","DOIUrl":"https://doi.org/10.1146/annurev-fluid-062520-115127","url":null,"abstract":"Reliable full-scale prediction of drag due to rough wall-bounded turbulent fluid flow remains a challenge. Currently, the uncertainty is at least 10%, with consequences, for example, on energy and ...","PeriodicalId":50754,"journal":{"name":"Annual Review of Fluid Mechanics","volume":null,"pages":null},"PeriodicalIF":27.7,"publicationDate":"2021-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45772698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Levitation and Self-Organization of Droplets","authors":"V. Ajaev, O. Kabov","doi":"10.1146/annurev-fluid-030620-094158","DOIUrl":"https://doi.org/10.1146/annurev-fluid-030620-094158","url":null,"abstract":"We review studies of levitating droplets over liquid–gas interfaces and dry solid surfaces with a focus on the physical mechanisms of levitation under different conditions. A fascinating physical p...","PeriodicalId":50754,"journal":{"name":"Annual Review of Fluid Mechanics","volume":null,"pages":null},"PeriodicalIF":27.7,"publicationDate":"2021-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46910739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Layering, Instabilities, and Mixing in Turbulent Stratified Flows","authors":"Colm‐cille P. Caulfield","doi":"10.1146/annurev-fluid-042320-100458","DOIUrl":"https://doi.org/10.1146/annurev-fluid-042320-100458","url":null,"abstract":"Understanding how turbulence leads to the enhanced irreversible transport of heat and other scalars such as salt and pollutants in density-stratified fluids is a fundamental and central problem in ...","PeriodicalId":50754,"journal":{"name":"Annual Review of Fluid Mechanics","volume":null,"pages":null},"PeriodicalIF":27.7,"publicationDate":"2021-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-fluid-042320-100458","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45859189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Fluid Mechanics of Tidal Stream Energy Conversion","authors":"T. Adcock, S. Draper, R. Willden, C. Vogel","doi":"10.1146/ANNUREV-FLUID-010719-060207","DOIUrl":"https://doi.org/10.1146/ANNUREV-FLUID-010719-060207","url":null,"abstract":"Placing mechanical devices into fast-moving tidal streams to generate clean and predictable electricity is a developing technology. This review covers the fundamental fluid mechanics of this applic...","PeriodicalId":50754,"journal":{"name":"Annual Review of Fluid Mechanics","volume":null,"pages":null},"PeriodicalIF":27.7,"publicationDate":"2021-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/ANNUREV-FLUID-010719-060207","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45541531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}