Effect of Density Change on Rapid Liquid-Solid Interface Kinetics and Heat Flow

1988 ◽  
Vol 100 ◽  
Author(s):  
Peter M. Richards
Keyword(s):  
Heat Flow ◽  
Latent Heat ◽  
Fast Moving ◽  
Density Change ◽  
Severe Limitation ◽  
Solid Interface ◽  
Interface Kinetics ◽  
Moving Liquid

ABSTRACTConsequences of the need to transport density to or from a fast-moving liquid-solid interface are examined. There can be a severe limitation of the freezing velocity and a change in the amount of heat which must be conducted. The latter effect produces a net latent heat which can be significantly different from the equilibrium value and even change sign.

Direct measurements of liquid/solid interface kinetics during pulsed‐laser‐induced melting of aluminum

1986 ◽  
Vol 48 (4) ◽  
pp. 278-280 ◽  
Author(s):  
J. Y. Tsao ◽  
S. T. Picraux ◽  
P. S. Peercy ◽  
Michael O. Thompson
Keyword(s):  
Pulsed Laser ◽  
Solid Interface ◽  
Interface Kinetics ◽  
Direct Measurements

scholarly journals Heat Flow Analysis of Inner Groove Tube for Latent Heat Exchanger in Condensing Gas Boiler

2014 ◽  
Vol 15 (7) ◽  
pp. 4052-4056 ◽  
Author(s):  
Kyeong-Jung Yong ◽  
Byung-Chul Lim ◽  
Sang-Heup Park
Keyword(s):  
Heat Exchanger ◽  
Heat Flow ◽  
Latent Heat ◽  
Flow Analysis

scholarly journals Tópicos do Método da Razão de Bowen

UNICIÊNCIAS ◽  
2021 ◽  
Vol 25 (1) ◽  
pp. 64-68
Author(s):  
Osvaldo Alves Pereira ◽  
Victor Hugo de Moraes Danelichen ◽  
Noel Flávio Costa Ferreira ◽  
Eduardo Nogueira dos Santos ◽  
Jonathan Willian Zangeski Novais ◽  
...  
Keyword(s):  
Heat Flow ◽  
Latent Heat ◽  
Physical State ◽  
Natural Process ◽  
Temperature Gradients ◽  
Water Volume ◽  
Flowing Water ◽  
Evaporation Process ◽  
Heat Flows ◽  
Mathematical Foundations

Este trabalho teve como objetivo mostrar a dedução física e matemática do método de Bowen na conversão de fluxo de calor latente em unidade de volume de água. A evapotranspiração é o processo natural de fluxo de água para atmosfera. Dentre as técnicas meteorológicas existentes, o método de Bowen consiste na razão entre os fluxos de calor latente (energia destinada para mudança de estado físico da água) e sensível (energia destinada para mudança de temperatura) emitidos por uma superfície durante o processo de evaporação e transpiração das plantas, em função dos gradientes da pressão de vapor e da temperatura observados sobre a superfície. Além disso, o método está fundamentado no princípio de conservação de energia, com fundamentos matemáticos relativamente simples e com modesto aparato instrumental.   Palavras-chaves: Fluxo de calor; micrometeorologia; perda de água; atmosfera.   Abstract This work aimed to show the physical and mathematical deduction of the Bowen method in the conversion of latent heat flow into a unit of water volume. Evapotranspiration is the natural process of flowing water into the atmosphere. Among the existing meteorological techniques, the Bowen method consists of the ratio between the latent heat flows (energy destined to change the physical state of the water) and sensitive (energy destined to change the temperature) emitted by a surface during the evaporation process and plant transpiration, depending on the vapor pressure and temperature gradients observed on the surface. In addition, the method is based on the principle of energy conservation, with relatively simple mathematical foundations and with modest instrumental apparatus.   Keywords: Heat flow; micrometeorology; loss of water; atmosphere.

An Analysis of Sensible and Latent Heat Flow in a Partially Frozen Unsaturated Soil

1978 ◽  
Vol 42 (3) ◽  
pp. 379-385 ◽  
Author(s):  
M. Fuchs ◽  
G. S. Campbell ◽  
R. I. Papendick
Keyword(s):  
Heat Flow ◽  
Latent Heat ◽  
Unsaturated Soil

scholarly journals Heat flow from wet to dry snowpack layers and associated faceting

2004 ◽  
Vol 38 ◽  
pp. 187-194 ◽  
Author(s):  
Bruce Jamieson ◽  
Charles Fierz
Keyword(s):  
Approximate Solution ◽  
Heat Flow ◽  
Snow Cover ◽  
Water Content ◽  
Latent Heat ◽  
Basic Equation ◽  
Freezing Time ◽  
Snow Layer ◽  
Wet Snow ◽  
Good Agreement

AbstractLayers of faceted crystals adjacent to crusts form the failure layers for some unexpected dry-slab avalanches. This paper focuses on the case of facets that form when dry snow overlies wet snow. From a basic equation for heat flow in solids, the approximate freezing time of the wet layer is derived. Seven experiments are described in which a wet layer was placed between two dry-snowlayers in a cold laboratory. Measured freezing times are comparable to the freezing times from the approximate solution assuming that latent heat from the irreducible water content flowed up. In four of the experiments, evidence of faceting was observed at the base of the upper dry snow layer within 5 hours and before the wet layer froze. In all seven experiments faceting was observed in the upper dry layer after the wet layer froze. Simulations performed with the snow-cover model SNOWPACK yield freezing times that agree reasonably with the approximate solution and allow the influence of various parameters on the results to be explored. In addition, simulated temperatures and grain evolution are compared with observations, showing good agreement.

A Dvelopment of Pump-Driven Type Mechanical Accumulator for utilizing Latent Heat Flow Thermal Control Systems

2003 ◽  
Vol 2003.78 (0) ◽  
pp. _8-17_-_8-18_
Author(s):  
Motohiro OHNO ◽  
Terushige FUJII ◽  
Hitoshi ASANO ◽  
Katsumi SUGIMOTO
Keyword(s):  
Heat Flow ◽  
Control Systems ◽  
Latent Heat ◽  
Thermal Control

The Crystallization and Amorphization of Si from the Melt at Interface Velocities Approaching 20 m/sec

1981 ◽  
Vol 4 ◽  
Author(s):  
J. M. Poate
Keyword(s):  
Heat Flow ◽  
Amorphous Phase ◽  
Interface Velocity ◽  
Solidification Velocity ◽  
Laser Melting ◽  
Substrate Orientation ◽  
Significant Lowering ◽  
Solid Interface ◽  
Amorphous Si

ABSTRACTLaser melting has been used to controllably vary the Si solidification velocity in the range 1–20 m/sec. The segregation of implanted impurities is found to be critically dependent on the liquid-solid interface velocity and substrate orientation for velocities <10 m/sec. This behavior can be understood in terms of different degrees of undercooling of the melt. While the (100) epitaxy is generally excellent up to velocities ∼10 m/sec, twins are observed for (111) epitaxy in the range ∼5–10 m/sec. Amorphous Si is produced from the melt for velocities in the vicinity of 20 m/sec. The amorphous phase forms at lower velocities on the (111) interface than on the (100) interface. These estimates of interface velocities come from heat flow calculations which do not include undercooling of the melt. Undercooling does not affect interface velocities ∼3 m/sec but significant lowering of the higher velocities could result from such effects.

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