fuktdynamiska

Fuktdynamiska, or moisture dynamics, is the study of how moisture moves, is stored, and changes phase in porous materials and environments as conditions such as humidity and temperature evolve. The field combines transport phenomena, sorption, and phase transitions to describe transient moisture behavior in solids, soils, foods, and textiles. It is a core part of hygro-thermal physics and is widely used in building physics, agriculture, and materials science.

Key processes in fuktdynamiska include vapor transport through pore networks by diffusion, liquid transport by capillary flow, and sorption and desorption to pore surfaces. Condensation and evaporation alter the moisture content and phase state of the material. The moisture response is often coupled to heat transfer, so temperature changes influence diffusion and sorption, while moisture content affects thermal properties. Models typically use diffusion or Fick-type laws for vapor transport, Darcy-type descriptions for liquid movement, and material-specific sorption isotherms with possible hysteresis. The effective diffusivity and sorption characteristics depend on moisture content and temperature.

Measuring and modeling methods in fuktdynamiska involve experiments such as dynamic vapor sorption to characterize sorption isotherms and diffusivities, gravimetric techniques, and moisture sensors for transient monitoring. Numerical simulations solve coupled partial differential equations for moisture and heat in one-, two-, or three-dimensional domains, using material data obtained from experiments and literature.

Applications are diverse and include predicting moisture loads and condensation risk in buildings, evaluating hygroscopic materials, preventing moisture-related damage like rot and mold, optimizing packaging and storage of foods, and understanding soil moisture dynamics in agriculture. The field is interdisciplinary, bridging physics, chemistry, engineering, and materials science.