Abstract:

Cell shape was modeled as a hollow rectanglar body from the cell structure of wood. The formula of thermal resistance of a material was derived by analogy, on the base of the fact that heat conduction of the material was similar to its electric conduction in terms of Ohm' resistance law. Theoretical expression of wood thermal conductivity in tangential direction was obtained from the cell shape model and the formula of thermal resistance. The theoretical expression showed that the wood thermal conductivity in tangential direction was a function of fraction void volume in wood. The greater the the fraction void volume was, the smaller the thermal conductivity was. Theoretical values of thermal conductivity were calculated with the derived expression for 24 tree species. The maximum error is 12.6% and average error is below 6.4% between existing experimental values and calculated ones for investigated species in this work.

Key words: thermal conductivity, thermal resistance, wood, tangential direction