Application of a Mathematical Model to the Analysis of the Influence of Length and Diameter on Log Drying Rate


  • Maurice Defo
  • Gilles Brunette


Wood yard, log drying model, diameter and length effects


A mathematical model based on the water potential concept was used to simulate the effect of length and diameter on the drying rate of aspen logs. The moisture content-water potential relationship and the effective water conductivity were determined during independent experiments. The set of equations describing heat and mass transfer during the drying process were solved by the finite element method. As expected, diameters and lengths had a strong effect on log drying rate. Smaller diameter logs dried faster than larger ones. Shorter logs dried faster than longer ones. Over a critical diameter or length value, however, there was no further marked difference in drying rate for larger or longer logs. For a given length, drying was predominantly radial in smaller diameter logs, whereas in larger logs, longitudinal drying was predominant. For longer logs, drying occurred essentially in the radial direction.


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