Determination of the Material Property Variations Across the Growth Ring of Softwood for Use in a Heterogeneous Drying Model Part 1. Capillary Pressure,Tracheid Model and Absolute Permeability
Determination of the Material Property Variations Across the Growth Ring of Softwood for Use in a Heterogeneous Drying Model Part 1. Capillary Pressure,Tracheid Model and Absolute Permeability
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DOI：
10.1515/hf.2001.052
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发表时间：
2001-04
期刊：
影响因子：
--
通讯作者：
P. Perré;I. Turner
中科院分区：
文献类型：
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作者：
P. Perré;I. Turner
在这项工作中，通过显微观察和实验工作相结合，国立农业学院（Ecole Nationale du gansnie Rural des Eaux et Forêts）获得的关于木材的广泛知识被用于假设软木宏观异质“Cerne”生长环模型的材料属性相关性。图像分析和均质化等数学工具被用于开发模型，以捕获木材样本中重要宏观物理参数的密度变化的影响。第一部分是根据达西定律研究木材的传质。从图像分析中推导出毛细管压力随局部密度的相关性。在此基础上，提出了软木的管胞模型。根据解剖观察，它的形状从早期坞到晚期坞演变。根据池内的泊泽维尔流动，并假设池内的流动-压力损失呈线性关系，通过该模型计算出液体和气体的渗透率值。
Summary In this work, the extensive knowledge of wood gained at the Ecole Nationale du Génie Rural des Eaux et Forêts by using a combination of microscopic observation and experimental work is being used to postulate material property correlations for a macroscopic heterogeneous “Cerne” growth ring model of softwood. Mathematical tools such as image analysis and homogenisation are used to develop models that capture the effect of the density variation within the wood sample of important macroscopic physical parameters. This first part is devoted to mass transfer in wood due to Darcy's law. Capillary pressure correlations as a function of local density are deduced from image analysis. Thereafter, a tracheid model is proposed for softwood. Its shape evolves from earlywood to latewood according to anatomical observations. Liquid and gaseous permeability values are calculated from this model according to Poiseuille's flow within cells and assuming a linear flow-pressure loss relationship through the pits.