Baroclinic waves in a rotating fluid subject to internal heating

1970 ◽  
Vol 268 (1186) ◽  
pp. 201-232 ◽  
Keyword(s):  
Axisymmetric Flow ◽  
Side Wall ◽  
The Body ◽  
Radial Dependence ◽  
Outer Side ◽  
Rotating Fluid ◽  
Baroclinic Waves ◽  
Heating And Cooling ◽  
Side Walls ◽  
Periodic Fluctuations

Free thermal convection in a vertical rotating fluid annulus subject to axisymmetric heating and cooling applied at the side-walls has been the subject of extensive previous studies, one of the principal findings of which is that four distinct types of flow are possible, each characteristic of definite ranges of impressed experimental conditions. Three of these flow types are characterized by departures from axial symmetry and arise when the basic axisymmetric flow is ‘ baroclinically unstable ’; they comprise ‘ baroclinic waves ’ of varying degrees of complexity (steady waves, waves subject to periodic fluctuations in form, amplitude and/or wavenumber (‘vacillation’) and waves subject to irregular non-periodic fluctuations). The present paper reports an experimental and theoretical study of effects associated with the introduction of heat throughout the body of the fluid (rather than via one of the side-walls) and removal via the inner side-wall, the outer side-wall, or both side-walls simultaneously. The experiments show that the principal characteristics of the flow are fairly insensitive to the radial dependence of heating and cooling (upon which, for example, the horizontal shear of the basic axisymmetric flow depends), thereby strengthening the basis of the application to large-scale geophysical and astrophysical systems of theoretical ideas stemming from the laboratory work. Just as previous experiments have shown that the presence of an inner wall does not preclude the occurrence of irregular baroclinic waves, one of the present experiments shows that the absence of an inner wall does not preclude the occurrence of steady baroclinic waves (thus refuting a certain conjecture which seems to have gained widespread acceptance among meteorologists). Determinations have been made of the general form of the flow pattern, top-surface flow velocities, total heat transfer and the transition between axisymmetric flow and baroclinic waves, and the results interpreted, where possible, in terms of theoretical ideas. The experiments provide striking support for a simple theoretical model that treats the jet stream associated with the baroclinic waves as a quasigeostrophic detached thermal boundary layer.

On the steady motions produced by a stable stratification in a rapidly rotating fluid

1967 ◽  
Vol 29 (4) ◽  
pp. 673-690 ◽  
Author(s):  
V. Barcilon ◽  
J. Pedlosky
Keyword(s):  
Side Wall ◽  
Fluid Flows ◽  
Stable Stratification ◽  
Rotating Fluid ◽  
Wide Range ◽  
Ekman Layers ◽  
Gradual Disappearance ◽  
Interior Flow ◽  
Side Walls ◽  
Steady Motions

The equilibrium state of a rapidly rotating fluid, heated uniformly from above and cooled uniformly from below while contained in a cylinder with insulated side-walls is studied.The circulations which are produced by the resulting stratification are studied over a wide range of parameters and it is shown that many of the features of the linear theory of rotating stratified fluid flows found in earlier studies reappear in this non-linear problem.These include the gradual disappearance of Ekman layer suction and O(1) Ekman layers as the stratification increases, and the determination of the interior flow by the side-wall boundary layers in conjunction with the Ekman layers.It is suggested therefore, that studies of rotating stratified flows which are unbounded laterally may frequently be defective and lead to solutions which are not the limit of any physically realizable experiment.

Laboratory and numerical studies of baroclinic waves in an internally heated rotating fluid annulus: a case of wave/vortex duality?

1997 ◽  
Vol 337 ◽  
pp. 155-191 ◽  
Author(s):  
P. L. READ ◽  
S. R. LEWIS ◽  
R. HIDE
Keyword(s):  
Numerical Simulations ◽  
Potential Vorticity ◽  
Axisymmetric Flow ◽  
Zonal Flow ◽  
Chaotic Advection ◽  
Rotating Fluid ◽  
Mean Flow ◽  
Baroclinic Waves ◽  
Vortex Merging ◽  
Flow Components

The structure, transport properties and regimes of flow exhibited in a rotating fluid annulus, subject to internal heating and sidewall cooling, are studied both in the laboratory and in numerical simulations. The performance of the numerical model is verified quantitatively to within a few per cent in several cases by direct comparison with measurements in the laboratory of temperature and horizontal velocity fields in the axisymmetric and regular wave regimes. The basic azimuthal mean flow produced by this distribution of heat sources and sinks leads to strips of potential vorticity in which the radial gradient of potential vorticity changes sign in both the vertical and horizontal directions. From diagnosis of the energy budget of numerical simulations, the principal instability of the flow is shown to be predominantly baroclinic in nature, though with a non-negligible contribution towards the maintenance of the non-axisymmetric flow components from the barotropic wave–zonal flow interaction. The structure of the regime diagram for the internally heated baroclinic waves is shown to have some aspects in common with conventional wall-heated annulus waves, but the former shows no evidence for time-dependence in the form of ‘amplitude vacillation’. Internally heated flows instead evidently prefer to make transitions between wavenumbers in the regular regime via a form of vortex merging and/or splitting, indicating a mixed vortex/wave character to the non-axisymmetric flows in this system. The transition towards irregular flow occurs via a form of wavenumber vacillation, also involving vortex splitting and merging events. Baroclinic eddies are shown to develop from an initial axisymmetric flow via a mixed sinuous/varicose instability, leading to the formation of detached vortices of the same sign as the ambient axisymmetric potential vorticity at that level, in a manner which resembles recent simulations of atmospheric baroclinic frontal instability and varicose barotropic instabilities. Dye tracer experiments confirm the mixed wave/vortex character of the equilibrated instabilities, and exhibit chaotic advection in time-dependent flows.

The axisymmetric convective regime for a rigidly bounded rotating annulus

1968 ◽  
Vol 32 (4) ◽  
pp. 625-655 ◽  
Author(s):  
Michael E. Mcintyre
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Axisymmetric Flow ◽  
Side Wall ◽  
Boundary Layer Equations ◽  
Wall Boundary Layer ◽  
Ekman Layers ◽  
Interior Flow ◽  
Side Walls ◽  
Annular Container

The axisymmetric flow of liquid in a rigidly bounded annular container of heightH, rotating with angular velocity Ω and subjected to a temperature difference ΔTbetween its vertical cylindrical perfectly conducting side walls, whose distance apart isL, is analysed in the boundary-layer approximation for small Ekman numberv/2ΩL2, withgαΔTHv/4Ω2L2K∼ 1. The heat transfer across the annulus is then convection-dominated, as is characteristic of the experimentally observed ‘upper symmetric regime’. The Prandtl numberv/kis assumed large, andHis restricted to be less than about 2L. The side wall boundary-layer equations are the same as in (non-rotating) convection in a rectangular cavity. The horizontal boundary layers are Ekman layers and the four boundary layers, together with certain spatialaveragesin the interior, are determined independently of the interior flow details. The determination of the latter comprises a ‘secondary’ problem in which viscosity and heat conduction are important throughout the interior; the meridional streamlines are not necessarily parallel to the isotherms. The secondary problem is discussed qualitatively but not solved. The theory agrees fairly well with an available numerical experiment in the upper symmetric regime, forv/k[bumpe ] 7, after finite-Ekmannumber effects such as finite boundary-layer thickness are allowed for heuris-tically.

The symmetric state of a rotating fluid differentially heated in the horizonal

1959 ◽  
Vol 6 (4) ◽  
pp. 599-620 ◽  
Author(s):  
Allan R. Robinson
Keyword(s):  
Boundary Layers ◽  
Cross Section ◽  
Side Wall ◽  
Hadley Cell ◽  
Main Body ◽  
Rotating Fluid ◽  
Independent State ◽  
Convective Processes ◽  
A Cell ◽  
Side Walls

The motion of a fluid inside a rotating annulus of square cross-section, whose dimensions are small compared with the distance from the axis of rotation, is considered. The rigid side walls are held at different constant temperatures and the fluid motions that occur are strongly influenced by Coriolis accelerations. A detailed study is made of the azimuthally independent state, a Hadley cell, in the limit of small thermal Rossby number. It is convenient to employ a boundary layer type analysis, essentially with respect to the Taylor number and all the imposed boundary conditions are rigorously satisfied.An entirely geostrophic thermal wind is found to obtain over the main body of the fluid. The circulation in the plane of the annular cross-section is entirely confined within narrow boundary layers and consists of a superposition of three cellular motions: a cell occupying the cross-section and two additional cells confined to the side-wall boundary layers. These motions are intimately related to the rotational constraint. The temperature distribution and its relation to the conductive and convective processes are determined.

Innovative approaches in the organization of closed waste-free production of organic pork using cultural and natural agricultural land

2020 ◽  
pp. 15-25
Author(s):  
Volodymyr Ivanov ◽  
Andrii Onyshchenko ◽  
Liudmyla Ivanova ◽  
Liudmyla Zasukha ◽  
Valerii Hryhorenko
Keyword(s):  
Agricultural Land ◽  
Side Wall ◽  
Front Wall ◽  
Lower Edge ◽  
Metal Mesh ◽  
Two Phase ◽  
Transparent Plastic ◽  
Pork Production ◽  
Young Pigs ◽  
Side Walls

The mobile house for two-phase litter rearing piglets was developed in the conditions of pasture their housing, the feature of which is that its side walls and roof are made in the form of two similar in shape and length of arched panels. In the back wall of the inner shield is a litter box, a self-feeder for piglets, a feed unit for a sow and a wicket, and in the front wall of the outer shield are doors with a wicket. Along with this, all walls and the roof of the litter box are made of transparent plastic, and the wall located near the self-feeding trough is also made perforated. In addition, the lower edge of the side wall of the inner arch-shaped shield has slides in which the lower edge of the side wall of the outer arc-shaped shield is inserted. A house with transformable fences has been developed to rear the young pigs. The structural feature of the house is the presence on the outside of the walls of the bobbins with a metal mesh edged at the bottom with a flexible sleeve. In order to ensure the conditions of gentle etching of the vegetation cover and to prevent damage to the turf of the pasture, the house can be completed with another type of hedge consisting of two hinged sections with doors on each side of the fence. In addition, the horizontal wings are rigidly attached to the hedge and connected by a metal mesh around the perimeter, the size of the cells of which ensures that the grass is eaten but prevents the turf of the pasture from being undermined. The developed devices for camp-pasture and feeding of maternal stock, suckling pigs, weaning pigs, repair and fattening pigs are well suited for year-round closed non-waste organic pork production using cultural and natural agricultural land. Key words: housing, feeding, devices, sows, piglets, young animals, pasture, organic pork.

Drinking Tubes on Archaeological Vessels from Western South America

1954 ◽  
Vol 20 (2) ◽  
pp. 149-153
Author(s):  
Stig Rydén
Keyword(s):  
South America ◽  
The Body ◽  
Outer Side ◽  
Human Face ◽  
La Paz

In 1952 I had the opportunity of investigating about 70 slab cists in the province of Munecas, Bolivia. Among the vessels found in the graves there were a few goblets provided with a tubular protuberance on one side. As my collections and personal outfit are still detained by the Bolivian authorities, the appearance of these vessels is illustrated here only by a drawing of a vessel taken over by the Museo Nacional “Tihuanacu,” La Paz (Fig. 50). A similar but undecorated vessel from the same region, Tacacacoma, is published by Schmidt (1929: 256, and Fig. 2). On the latter vessel the tubular protuberance is joined to the body of the goblet by two bare. Other minor variations in vessels of this type appear in the shape of the goblets and in the shape and placing of the tubular protuberance. Sometimes, for instance, the tube is longer than on the vessels depicted here and very often a raised human face is found on the outer side opposite the tube.

Designing a detachable body with sliding side walls and a roof

2021 ◽  
Vol 18 (1) ◽  
pp. 62-71
Author(s):  
O. I. Zaynitdinov ◽  
Keyword(s):  
Practical Importance ◽  
Atmospheric Precipitation ◽  
Middle Part ◽  
The Body ◽  
3D Design ◽  
Car Body ◽  
Simultaneous Loading ◽  
Side Walls ◽  
Loading And Unloading ◽  
Technical Solutions

Objective: Selection of technical solutions for designing a covered detachable body fence with sliding side walls and a roof. Methods: A detachable body with sliding side walls and a roof was designed in accordance with several technical and regulatory documents using the KOMPAS-3D design software. Results: The covered detachable body with sliding side walls and a roof designed for the carriage of goods that require protection from atmospheric precipitation has been proposed. A scheme of a lock for side sliding doors and a linkage scheme of the doors’ middle part have been developed. Drawings of the main load-bearing elements of the car body are presented, including the underframe with three longitudinal and several transverse and auxiliary beams. The diagram of fastening the sliding door roller assemblies on the car body to the lower longitudinal beams and to the upper beam is given. Practical importance: The covered detachable body with sliding side walls and a roof allows reducing the time and human effort of loading and unloading the car, provides simultaneous loading and unloading of goods both from the side and from the top of the body using various hoisting devices.

Sensitivity of Thermal Conductivity of Carbon Nanotubes to Defect Concentrations and Heat-Treatment

2012 ◽  
Author(s):  
Michael F. P. Bifano ◽  
Jungkyu Park ◽  
Vikas Prakash
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Interatomic Potential ◽  
Side Wall ◽  
Chemical Vapor ◽  
Md Simulations ◽  
Heat Treated ◽  
Side Walls ◽  
Non Equilibrium Molecular Dynamics ◽  
Vacancy Concentrations

In the present study, classical MD simulations using reverse non-equilibrium molecular dynamics with the AIREBO interatomic potential are used to investigate the sensitivity of thermal conductivity in SWCNTs to side-wall defect concentration and heat-treatment. Two types of defects are investigated. First, the thermal conductivity of (6,6) SWCNTs is obtained as a function of concentration of chemisorbed hydrogen adatoms. Secondly, the thermal conductivity is obtained as a function of point-vacancy concentrations. The results of the studies show that 2 atom% of hydrogenation and 1.5–2% vacancy concentrations have very similar detrimental effects on the thermal conductivity of SWCNT. Vacancy repair is evident with heat treatment, and heat-treatments at 3000°C for up to 22 ns are found to transform point vacancies into various types of non-hexagonal side-wall defects; this vacancy repair is accompanied by a ca. 10% increase in thermal conductivity. Thermal conductivity measurements in both heat-treated and non-heat treated chemical vapor deposition grown MWCNTs are also reviewed. The results suggest that CNT thermal conductivity can be drastically increased if measures are taken to remove common defects from the SWCNT side-walls.

scholarly journals A Triggering Mechanism for Rapid Intensification of Tropical Cyclones

2015 ◽  
Vol 72 (7) ◽  
pp. 2666-2681 ◽  
Author(s):  
Yoshiaki Miyamoto ◽  
Tetsuya Takemi
Keyword(s):  
Boundary Layer ◽  
Numerical Experiments ◽  
Axisymmetric Flow ◽  
Three Dimensional ◽  
Tangential Velocity ◽  
Convective Cell ◽  
Rapid Intensification ◽  
Rotating Fluid ◽  
Coriolis Parameter ◽  
Maximum Tangential Velocity

Triggering processes for the rapidly intensifying phase of a tropical cyclone (TC) were investigated on the basis of numerical experiments using a three-dimensional nonhydrostatic model. The results revealed that the rapid intensification of the simulated TC commenced following the formation of a circular cloud, which occurred about 12 h after the TC became essentially axisymmetric. The circular cloud (eyewall) evolved from a cloudy convective cell that was originally generated near the radius of maximum wind speed (RMW). The development of the convective cell in the eyewall was closely related to the radial location of the strong boundary layer convergence of axisymmetric flow. The radius of maximum convergence (RMC) was small relative to the RMW when the TC vortex was weak, which is consistent with the boundary layer theory for a rotating fluid system on a frictional surface. As the TC intensified, the RMC approached the RMW. An eyewall was very likely to form in the simulated TC when the RMC approached the RMW. Because the RMC is theoretically determined by a Rossby number defined by the maximum tangential velocity, RMW, and Coriolis parameter, a series of numerical experiments was conducted by changing the three parameters. The results were consistent with the hypothesis that intensification occurs earlier for larger Rossby numbers. This finding indicates that initial TC vortices with larger Rossby numbers are more likely to experience rapid intensification and, hence, to evolve into strong hurricanes.

scholarly journals The current distribution in an electrochemical cell. Part VII. Concluding remarks

2002 ◽  
Vol 67 (4) ◽  
pp. 273-278 ◽  
Author(s):  
Konstantin Popov ◽  
S.M. Pesic ◽  
Predrag Zivkovic
Keyword(s):  
Process Parameters ◽  
Current Distribution ◽  
Current Density ◽  
Electrochemical Cell ◽  
Side Wall ◽  
Cell Geometry ◽  
Electrode Edge ◽  
Side Walls ◽  
In Cells

Anew method for the determination of the ability of an electrolyte to distribute uniformly current density in an electrochemical cell is proposed. It is based on the comparison of the current in cells in which the electrode edges touch the cell side walls with the current in cells with different electrode edge ? cell side wall distances. The effects of cell geometry process parameters and current density are discussed and illustrated using the results presented in the previous papers from this series.

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