Fluid dynamic models of ozone application in stored maize¹

Modelos fluidodinâmicos de aplicação de ozônio em milho armazenado

In recent years, grain storage in Brazil underwent a 1.5% increase in its available capacity, leading to a high demand for grain treatment in the country. This study aims to evaluate two computational models for grain distribution within stored maize, comparing their ability to predict the effectiveness of ozone application. Specifically, it was investigated whether a heterogeneous model, which accounts for variations in grain density and location, provides results more compatible with experimental observations in the literature. By comparing the predictive capabilities of both models, this study will contribute to developing more effective and targeted strategies for ozone-based pest control in stored grain. In the heterogeneous model, the smaller grains accumulate in the center of the container. The study uses the Stokes-Brinkman model and ozone transport equations in porous media. It was observed that the grain distribution model affects the spatial distribution of ozone concentration inside the container. In the heterogeneous grain distribution model, the region of larger grains presents a lower ozone absorption since supposedly a smaller number of ozone elimination reactions occur on the grain surfaces.

Key words:
transport of diluted species; porous media; computational fluid dynamics

The results of ozone distribution in the grain mass are affected by modifying the grain distribu-tion model in the container.

In a homogeneous grain distribution model, ozone absorption near the container walls is more elevated.

In a heterogeneous model, where smaller grains accumulate in the center, ozone absorption near the central axis is greater.