Two-equation oxygen diffusivity of apple cortex tissue for multiscale modeling of gas exchange

© 2018 EUROSIS-ETI. A two-equation multiscale model was developed for diffusive oxygen transport in apple cortex tissue. Effective diffusivity of oxygen in both the pore and the cell phase was computed for the 3D microstructure of Jonagold cortex. Microstructure images were obtained with high resolution X-ray CT, and used in microscale simulations of gas diffusion with a voxel based finite volume method. The effective diffusivity of the liquid phase was as expected normally distributed, while the effective diffusivity of the gas phase showed a bimodal distribution. This was caused by the low pore connectivity of some of the 3D microstructures as 10 out of the 16 used samples did not show any open porosity. The 3D microstructure of the apple tissue imposed a significant reduction in the gaseous diffusivity. A comparison was made with the effective tissue diffusivity of a one-equation model for oxygen diffusion, assuming phase equilibrium. Good correspondence was found between the two models for the microscale properties of the tissues used. The large variation in the equilibrium effective tissue diffusivity that was obtained earlier could thus be explained by the variability in open porosity of apple cortex tissue.

ISBN:9789492859013

Jaar van publicatie:2018

Toegankelijkheid:Open