摘要:

A new method for solution of thermal fields.around arrays of large pipes is described. It is shown that increased interaction between members of the array can be matched by appropriate splitting and variation of intensities of sources, sinks and dipoles with a view to maintain boundary conditions. Rapidly converging series of elementary analytic functions provide high accuracy for a wide range of array packing. In this context a specific example of a system comprising a wall heated on one side and cooled by array of pipes is considered

ISSN:0098-6445    

DOI:10.1080/00986448308940271

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0098-6445    

DOI:10.1080/00986448308940272

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The effective viscosity of elastic and inelastic liquids has been determined from the power consumption in stirred tanks

ISSN:0098-6445    

DOI:10.1080/00986448308940273

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

An explicit method for evaluating the kinetics of data obtained in an integral tubular reactor has been developed. The method is demonstrated for n:th order irreversible reactions by using experimental data. The reaction order is obtained from the slope and the rate constant is calculated from the intercept in a straight line plot

ISSN:0098-6445    

DOI:10.1080/00986448308940274

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The laminar dispersion of a solute in a capillary tube is used to measure diffusion coefficient of oxygen in liquids. A Polarographic type oxygen microelectrode is used to detect the pulse. Such a procedure overcomes the problems of measuring dissolved gases and makes it possible to apply this well known technique to oxygen-liquid systems. The results are in agreement with literature values

ISSN:0098-6445    

DOI:10.1080/00986448308940275

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Leaching or extraction by supercritical fluids (SCF) is a relatively new technology which offers several key advantages over traditional methods, especially enhanced solubility and rapid diffusion. Because the molecular properties are somewhere in between those of either liquid or gas, the design of SCF systems does not fit the classical mold based on intuitive or well-known rules of thumb. In the present work, transient transport for dissolution of solutes filling granulated porous media is studied for SCF leaching in spinning basket or slurry reactors. We present an approximate model based on taking the intraparticle composition profile to be always parabolic. This leads to a simple one-term expression (transportable on the back of a postage stamp) which is shown to compare very favorably with the more tedious exact solution. The approximate solution thus allows designers to quickly delineate those conditions, such as sampling times, which are realizable in the experimental sense. Moreover, it is shown that parameters such as diffusivity can be estimated directly, using only time-to-peak information. The specific results presented are directly applicable to SCF systems, but the analysis can be used for any extraction system

ISSN:0098-6445    

DOI:10.1080/00986448308940276

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The sorption rate of swelling penetrants in glassy polymers has been considered as controlled both by the swelling kinetics and the penetrant diffusion through the swollen layer. The stress exerted on the glassy core at the moving boundary is the driving force for the swelling, and results from an osmotic stress and a differential swelling stress contribution. During the sorption process, the osmotic stress at the moving boundary decreases, due to the increasing diffusion resistance; the differential swelling stress, on the contrary, increases giving rise to an acceleration of the front velocity (Super Case II).

ISSN:0098-6445    

DOI:10.1080/00986448308940277

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0098-6445    

DOI:10.1080/00986448308940278

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Equations have been written, and a computational scheme developed, for predicting flow fields and heat transfer phenomena associated with asymmetric gas-driven flows in systems of cylindrical geometry. Cases considered include axisymmetric gas injection wherein the gas-liquid plume is either of constant radius, or expands in a cone-like manner towards the surface. It is, thereby, shown that the model compares reliably with existing axisymmetric computations. Non-central gas flows are then considered and resulting 3-D liquid flow patterns computed. Finally, the temperature fields in an initially stagnant and thermally stratified liquid resulting from the local introduction of gas on the bottom surface is illustrated

ISSN:0098-6445    

DOI:10.1080/00986448308940279

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Micromixing is shown to proceed via three main mechanisms relying on the concept of “fluid aggregates”: (I) Laminar stretching (2) Turbulent erosion (3) Molecular diffusion, each with a characteristic time constant. Experiments are reported where chemical reactions are controlled by one or several of these processes. It is found that the ratio of the microfluid/macrofluid volumes is roughly equal to that of the reaction/ micromixing times. Tentative correlations are proposed to estimate the erosion and diffusion times and to calculate conversion and yield in micromixing controlled regime

ISSN:0098-6445    

DOI:10.1080/00986448308940280

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor