Abstract:The storage temperature field of an underground granary is an important factor affecting the quality of stored grain and the surrounding environment. In this study, Gambit software was used to build a 3-dimensional model of an underground granary. The model was meshed and variations of the grain heap temperature field under non-ventilated conditions during the storage process were studied using computational fluid dynamics (CFD) numerical simulation method. The mass conservation equation, momentum equations, and wall heat transfer equations in CFD software were optimized by writing and importing the user-defined function (UDF). Variations in the temperature field at a non-ventilated underground granary were obtained by iterative calculation and CFD software simulation. The results demonstrated a continuous heat and mass transfer between grain heaps and surrounding building structures, as well as between the grain heaps, with an increase in grain storage time in the underground granary. Additionally, the final temperature drew close to the constant local underground temperature. The results show that an underground granary is an economically feasible alternative for grain storage as well as provide a reference for the control of temperature of underground granaries and mechanical ventilation for grain heaps.
