Wyznaczanie współczynnika dyfuzji wilgoci w drewnie sosny zwyczajnej

• Autorzy: Świrska-Perkowska J. , Gajda M.

Warianty tytułu

EN

Determination of moisture diffusion coefficients for Scots pine wood

• Języki publikacji: PL

Abstrakty

EN

This paper presents an experimental research on the moisture diffusion coefficient in wood of Scots pine within the scope of hygroscopic moisture. It included measurements of kinetics of moisture adsorption within the range of air relative humidity from 25% to 85%.The experiment was carried out with unidirectional flow of moisture, in each of the material principal orthotropic directions. Values of moisture diffusion coefficients and mass surface emission coefficient were found using the method of minimizing the fitting function, that is by fitting the computational adsorption kinetics curves to the experimental curves. At the same time, four cases of variations of the moisture diffusion coefficient together with moisture content of the material have been analysed each time: in the form of a constant, linear function, quadratic function and exponential function, assuming a constant value of mass surface emission coefficient on the absorbing surface of samples. In addition, for the tangential and radial directions, the case of simultaneous linear variations of moisture diffusion coefficient and mass surface emission coefficient was examined. The performed calculations allowed determining what is the impact of various diffusion mechanisms on the whole process of transferring moisture in the considered cases.

Słowa kluczowe

PL

dyfuzja wilgoci; drewno; kinetyka sorpcji; minimalizacja funkcji celu

EN

diffusion of moisture; wood; sorption kinetics

• Wydawca: Komisja Inżynierii Budowlanej Polskiej Akademii Nauk Oddział w Katowicach
• Czasopismo: Roczniki Inżynierii Budowlanej
• Rocznik: 2015
• Tom: z. 15
• Strony: 17--27
• Opis fizyczny: Bibliogr. 10 poz., rys., tab., wykr.

Twórcy

autor

Świrska-Perkowska J.

• Wydział Budownictwa i Architektury, Politechnika Opolska, Opole, Polska

autor

Gajda M.

• Wydział Budownictwa i Architektury, Politechnika Opolska, Opole, Polska

Bibliografia

• [1] Engelund E.T., Thygesen L.G., Svenson S., Hill C.A.S.:A critical discussion the physics of wood-water interactions, Wood Science and Technology, 47, 2013, pp.141-161.
• [2] Kang W., Chung W.Y., Eom C., Yco H.: Some considerations in heterogeneous nonisothermal transport models for wood: a numerical study, Journal of Wood Science 54, 2008, pp. 267-277.
• [3] Olek W., Perré P., Weres J.: Implementation of a relaxation equilibrium term in the convective boundary condition for a better representation of the transient bound water diffusion in wood, Wood Science and Technology, 45, 2011, pp. 677-691.
• [4] Olek W., Weres J.: Effects of method of identification of the diffusion coefficient on accuracy of modeling bound water transfer in wood, Transport in Porous Media,66, 2007, pp. 135-144.
• [5] Silva W.P., Silva L.D., Oliveira Farias V.S., Silva C.M.D.P.S., Ataíde J.S.P.: Three-dimensional numerical analysis of water transfer in wood: determination of an expression for the effective mass diffusivity, Wood Science and Technology, 47, 2013, pp. 897-912.
• [6] Stamm A.J.: Wood and cellulose science, Ronald,1964, New York.
• [7] Świrska-Perkowska J.: Adsorpcja i ruch wilgoci w porowatych materiałach budowlanych w warunkach izotermiznych, Studia z Zakresu Inżynierii 77, KILiW PAN, 2012, Warszawa.
• [8] Wadsö L.: Studies of water vapour transport and sorption in wood, Dissertation, Lund University, 1993.
• [9] Xu H.L., Chung W.X.: Estimation of the chestnut mass transfer coefficient through its microscopic structure, Journal Korean of Wood Science and Technology, 40(5), 2012, pp. 352-362.
• [10] Zohou S., Agoua E., Degan G., Perre P.: An experimental correction proposed for an accurate determination of mass diffusivity of wood in steady regime, Heat and Mass Transfer 39, 2003, pp.147-155.

Uwagi

PL

Opracowanie ze środków MNiSW w ramach umowy 812/P-DUN/2016 na działalność upowszechniającą naukę.