Heat and Moisture Transfer in a Two-Layer Building Wall at Slow Harmonic Changes of Thermo-Humiditive Environment Parameters Based on The theory of Thermodiffusion in Solids
In order to describe the thermo-humiditive processes occurring in external building walls, the theory of thermodiffusion in elastic solids is used. This theory allows to take into account the internal coupling between the processes of heat conduction and moisture transfer, as well as it mak.es it possible to determine the stresses during these processes in the wall material. The solutions of the equations describing the process of heat and moisture transfer in a two-layer (and, in general, n-layer) building wall at slow harmonic changes of thermo-humiditive environment parameters are presented. The solutions obtained are of importance for thermo-humiditive design of building walls; the mean month's values of external climate parameters are assumed to vary sinusoidally during the year. The method of solution, as well as some notions, are based on the theory of electric transmission lines.
References
W .NOWACKI, Thermodiffusion in solids, in: Thermoelasticity, Ossolineum, Wrocław 1972 [in Polish].
J.S.PODSTRIGAČ, Differential equations for thermodiffusion problems in deformable isotropic solids [in Russian], DAN USSR, 2, 1961.
W.N.BOGOSŁOWSKI, Thermal and humiditive processes in buildings [transl. from Russian], Arkady, Warszawa 1985.
W.DUDZIAK, R.UKLEJEWSKI, Heat and moisture transfer in a building wall material layer at slow harmonic changes of thermo-humiditive environment parameters, based on the theory of thermodiffusion in solids [in Polish], Arch. Inż. Ląd., (to be published).
W.DUDZIAK, R.UKLEJEWSKI, On the application of the electrical transmission lines theory in thermodiffusion problems in solids, Bull. Acad. Polon. Sci., Série Sci. Techn., 34, 3-4, 1986.
WŁ.PŁOŃSKI, J.A.POGORZELSKI, Physics of building structures, Arkady, Warszawa 1978 [in Polish].
L.PIPES, Direct computation of transmission matrices of electrical transmission lines. Part I, II, J.Frankl.Inst., 281, pp.275-292, 387-405, 1966.
T.CHOLEWICKI, Electrical transmission lines and nonuniform ladder networks, PWN, Warszawa 1974 [in Polish].
T.CH0LEWICKI, Analysis of nonuniform electrical networks by means of the difference equations method, PWN, Warszawa 1982 [in Polish].
K.OGATA, State space methods in control theory, WNT, Warszawa 1974 [transl. from English].
J.WEHR, Electro-mechano-acoustical analogies for the systems with lumped and distributed parameters in the light of dimensional analysis [in Polish], Arch. Akustyki, 2, pp.211-226, 1967.
K.KIESSL, Kapillaren und dampfformiger Feuchtetransport in mehrschichtigen Bauteilen, Diss.Univ.Essen, Essen 1983.
R.KORONEN, A method to analyse the transient hygrothermal behaviour of building materials and components, Technical Research Center of Finland, Publ. 21, Espoo 1984.