Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
STUDY ON CONDENSATION IN POROUS MEDIA EMPLOYING THE LATTICE BOLTZMANN METHOD
Submission Author:
Marcelo Adriano Fogiatto , PR
Co-Authors:
Marcelo Adriano Fogiatto, Nathan Mendes, Paulo Philippi
Presenter: Paulo Philippi
doi://10.26678/ABCM.ENCIT2022.CIT22-0076
Abstract
The knowledge of moisture transfer through the building envelope is critically important in the study of building physics, specially when the envelope is made of porous materials. In this case, it may occur condensation in the cavities of the porous media, which may affect the HAM transfer through the wall. Among the main approaches to simulate this situation, there is the lattice Boltzmann method, which some features, such as the ability to work with complex geometries and the wide availability of multiphase models, are beneficial to this study. Considering a 2-D domain of 200x200 nm, with periodic north-south borders and density defined east and west boundaries at saturated vapor density, as well as the whole fluid domain initially, containing two 50 nm diameter solids, simulations were carried out for different distances between the solids. For a 30 nm distance, the saturated liquid layers around the solids did not reach each other, therefore there was no capillary condensation. On the other hand, for separations of 20 and 10 nm, it occurred. The liquid formation presented different shapes for each distance. An evaluation of the total mass in the domain throughout the time steps was performed to assure the liquid layer growth stopped beyond certain time.
Keywords
Porous media, Lattice Boltzmann method, capillary flows, condensation, multiphase flow
