Lattice Boltzmann modeling of the effective thermal conductivity in plant fiber porous media generated by Quartet Structure Generation Set

Abstract

This study proposes a novel approach that combines a Quartet Structure Generation Set (QSGS) algorithm with the Lattice Boltzmann Method (LBM) to investigate effective thermal conductivity in plant fiber materials. The QSGS algorithm is utilized to construct a two-dimensional digital structure of the porous media, enabling the determination of effective thermal conductivity through LBM simulations. The simulation results demonstrate good agreement with experimental data, exhibiting a maximum relative error of only 1.7%. The study examines the influence of key factors on effective thermal conductivity, including temperature, porosity, fiber distribution, and fractal dimension. The effective thermal conductivity increased by approximately 6.1% for each 10 °C increase in temperature between 10 °C and 50 °C. Moreover, the effective thermal conductivity showed an average decrease of 16.3% with each 10% increment in porosity. The increase in thermal conductivity becomes more significant with increasing temperature and decreasing porosity. Conversely, an increased fractal dimension correlates with a decline in effective thermal conductivity. The effective thermal conductivity is influenced synergistically by the directional growth probability of the solid phase and the direction of heat flow. The findings offer valuable insights into thermal conductivity behavior and heat transfer mechanisms in plant fiber porous media.