Triphasic Model of Heat and Moisture Transport with Internal Mass Exchange in Paperboard

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

Mixture theory is used to derive a triphasic model to describe processes in paperboard consisting of solid fiber, bound water and gas. The gas is viewed as a miscible mix of the two constituents dry air and water vapor. The governing equations are mass conservation laws for bound water, dry air, water vapor, and mixture energy balance. Constitutive relations are found by exploiting the macroscale dissipation inequality. Resulting constitutive equations include Fickian diffusion of water vapor and dry air, Darcian flow for gas and Fourier heat conduction for the mixture. Mass exchange between bound water, and water vapor due to adsorption/desorption is driven by the difference in chemical potential. The interaction function is based on equilibrium considerations for the bound water–water vapor system. From the description of the sorption isotherm, expressions for net isosteric heat and free energy related to water–fiber interaction are derived. The resulting thermodynamically consistent model is used to simulate moisture and heat dynamics for paperboard rolls. Simulation results are presented for a paperboard roll with anisotropic material properties subjected to a change in ambient relative humidity from 50 to 80 %.

Detaljer

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Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Teknisk mekanik
Originalspråkengelska
Sidor (från-till)381-408
Antal sidor28
TidskriftTransport in Porous Media
Volym112
Utgåva nummer2
StatusPublished - 2016
PublikationskategoriForskning
Peer review utfördJa

Relaterad forskningsoutput

Marcus Alexandersson, 2020 sep 1, Lund: Division of Solid Mechanics. 341 s.

Forskningsoutput: AvhandlingDoktorsavhandling (sammanläggning)

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