Bin stored wheat temperature simulation under South Mediterranean climate

Abstract

Cereal quality preservation is traditionally the accountability of grain storekeepers who count on profound knowledge discovered through scientific research. The main purpose of this research study was to predict the evolution of wheat temperature in unaerated silo during storage period under Tunisia climate. First, a bidimensional mathematical combined model (silo wall model + heat transfer model in grain bulk), which describes the distribution of the unsteady temperature in a cylindrical grain storage system, was presented and simulated using the parabolic solver incorporated in the Matlab 2015a environment. Mesh refinement at the shortest boundaries, including triangular elements, was adopted to simulate storage temperatures. In this numerical model, the influence of Newman boundary conditions, which include solar irradiation and air convection, on the evolution and distribution of grain temperatures was considered. Second, the model was validated by conducting experiments in a weathered galvanized steel silo with conical bottom, preserving wheat during the period of autumn 2019. Utilizing the climatic data of the region of Medjez El Bab, located in Western North of Tunisia, the variations in stored grain temperatures were interpreted in detail. The obtained results when comparing the observed versus numerical data proved an excellent agreement according to the correlation coefficients  for different measurement points (from 0.85 to 0.98), confirming that the developed model is an outstanding tool to monitoring and to predicting wheat conservation for regions with similar climate conditions as Tunisia.