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Title: Theoretical thermal conductivity equation for uniform density wood cells

Source: Wood and fiber science. Vol. 40, no. 2 (Apr. 2008): Pages 167-180

Author(s)Hunt, John F.; Gu, Hongmei; Lebow, Patricia

Publication Year: 2008  View PDF »

Category: Journal Articles
Associated Research Project(s):   FPL-4706-1A  FPL-4851-1A

Abstract: The anisotropy of wood creates a complex problem requiring that analyses be based on fundamental material properties and characteristics of the wood structure to solve heat transfer problems. A two-dimensional finite element model that evaluates the effective thermal conductivity of a wood cell over the full range of moisture contents and porosities was previously developed, but its dependence on software limits its use. A statistical curve-fit to finite-element results would provide a simplified expression of the model's results without the need for software to interpolate values. This paper develops an explicit equation for the values from the finite-element thermal conductivity analysis. The equation is derived from a fundamental equivalent resistive-circuit model for general thermal conductivity problems. Constants were added to the equation to improve the regression-fit for the resistive model. The equation determines thermal conductivity values for the full range of densities and moisture contents. This new equation provides thermal conductivity values for uniform-density wood material using inputs of only oven-dry density and moisture content. An explicit method for determining thermal conductivity of uniform density wood cells has potential uses for many wood applications.

Keywords: Resistive-circuit modeling, wood cell, thermal conductivity, moisture content, heat transfer, cellular structure, finite element modeling, anisotropy, mathematical models, softwood, porosity, thermal properties, heat transmission, heat flux, wood density, mass transfer, earlywood, latewood

File size: 577 kb(s)

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RITS Product ID: 26390
Current FPL Scientists associated with this product (listed alphabetically)
Gu, Hongmei
Forest Products Technologist
Hunt, John F.
Research General Engineer
Lebow, Patricia K.
Mathematical Statistician

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