The phase transformation from liquid to solid is a phenomenon central to a wide range of manufacturing and natural processes. The presence of phase transformation can drive convection in the melt through the liberation of latent heat, the rejection of solute, and the change of density upon freezing. The fluid mechanics itself can playa central role; the phase transformation can be strongly altered by convective transport in the liquid through the modification of the thermal and solutal environment of the solid-liquid interface; these local fields control the freezing characteristics at the interface. The convection can be generated naturally by buoyancy forces arising from gradients of temperature and concentration in the liquid, by density changes upon freezing, and by thermocapillary and solutocapillary forces on liquid-solid interfaces. The interactive coupling between solidification and convection forms the subject of this volume. Such coupled processes are significant on a large range of scales. Among the applications of interest are the manufacture of single crystals, the processing of surfaces using laser or molecular beams, and the processes of soldering and welding. One wants to understand and predict macrosegregation in castings, transport and fractionation in geological and geophysical systems, and heat accumulation in energy redistribution and storage systems. This volume contains papers presented at the NATO Advanced Research Workshop on "Interactive Dynamics of Convection and Solidification" held in Chamonix, France, March 8-13, 1992.

Klappentext

The phase transformation from liquid to solid is often tightly coupled with convective transport in the melt. Such coupled processes are significant on a broad range of scales. emInteractive Dynamics of/em emConvection and Solidification/em gives the first overview of the field as a whole. Both theoretical and experimental studies provide a fundamental understanding of the physical mechanisms involved. On the microscale, there are discussions of morphological instabilities, their finite-amplitude evolutions, and the development of cells and dendrites. On the mesoscale, there are discussions of developed' cells and dendrites, and of mushy zones. On the macroscale, there are discussions of full systems' of solidifying/melting and convecting material. Here the influence of flow on crystal-growing processes, processing by beams, spin casting, macrosegregation in casting and geological systems, and energy conversion in engineering systems are all discussed.

Zusammenfassung
Proceedings of the NATO Advanced Study Institute, Chamonix, France, March 8-13, 1992

Inhalt
Morphological Stability and Convective Flow: Some Old and New Problems.- Rayleigh-Marangoni Bilayer Convection in Liquid Encapsulated Crystal Growth.- Effect of Modulated Taylor-Vortex Flows on Crystal-Melt Interfaces.- Stimulated Convection and Morphological Instability.- Dynamics and Structure of an Aggregation Growing from a Diffusion Field.- Microscale Coupling of Solidification and Flow.- Weakly Nonlinear Morphological Instability Analysis of a Sphere Crystallizing from an Undercooled Melt.- Flow-Induced Spatio-Temporal Dynamics in Directional Solidification.- Long-Wave Interactions in Morphological and Convective Instabilities.- Nonlinear Analysis of Morphological Interactions between Flow and Interface Shape in the Directional Solidification of a Binary Alloy.- Nonlinear Dynamics near the Onset of Cellular Growth during Thin-Film Solidification of a Binary Alloy: on the Observability of Weakly Nonlinear States.- A Strongly Nonlinear Analysis of Morphological Stability of a Binary Alloy: Solutal Convection and the Effect of Density Mismatch.- Buoyant Convection near a Solidifying Dendrite.- Flow Interactions with Dendritic Mushy Zones.- Interaction of Thermal and Forced Convection with the Growth of Dendritic Crystals.- Effect of a Forced Flow on Dendritic Growth.- The Effect of Convection Motion on Dendritic Growth.- Nonlinear Dynamics in Cellular Solidification in Presence of Defects.- Surface Kinetics and Growth Morphologies of Nh4 Cl.- The Dynamics of Mushy Layers.- Convection in the Mushy Zone during Directional Solidification.- Studies of Channel-Plume Convection during Solidification.- The Onset of Freckling in the Solidification of Binary Alloys.- Nonequilibrium Effects in a Slurry.- New Experiments on Compositional Convection.- Convective Aspects of Solidification Experiments under Low Gravity.- Time Dependent Aspects of Solidification.- Optimization Applied to Solidification Processes.- Numerically Simulated Temperature Fields in a Gradient Furnace Modelling the Microgravity Environment.- Effect of Solidification Morphology on the Macroscopic Behavior of Solidification Systems.- Simulation of the Columnar Dendritic Solidification of a PbSn Alloy.- Scale Analysis and Numerical Simulation of Solidification of an Alloy Cooled at a Vertical Boundary.- Convective Effects on Solidification Grain Structure.- Buoyancy-Driven Melt Pool Convection during Laser Surface Treatment.- Laser Surface Alloying of A199.99 and AlSi10Mg with Cr and Ni.- Tin Ribbons Obtained by a Melt Spinning Process.- Solidification by Planar-Flow Spin-Casting.- A Numerical and Experimental Study of Wavy Ice Structure in a Parallel Plate Channel.- Dynamical Solidification of the Liquid Flowing in a Cooling Cylindrical Channel.- Convection and Macrosegregation in Magma Chambers.- Rotating Convection.- Solidification and Convection in the Core of the Earth.- Convection Driven Phase Change and Mass Transfer.- Closure.- Cartoon.