Coupled CFD-FEM Analysis of the Damage Causes of the Retention Bunker: A Case Study at Hard Coal Mine

Abstract Underground coal storage bunkers are built to equalize coal output, guarantee continuity of the excavated coal transport, and store coal at the point where the nature of the transport changes from continuous to periodic. The physical properties of stored coal in underground coal storage bunkers are unpredictable and prone to sudden changes, especially for the coal mines that operate under water hazards. Interaction with underground water changes the state of solid coal and forms a coal-water mixture. The hydromixture radically changes the conditions of internal hydrostatic loading. The main goal of the paper was to determine the values of pressure field variations exerted by the flowing hydromixture. The influence of the internal pressure loading change on the stress distribution in the underground coal storage bunker was tested. The changes in the underground coal storage bunker's pressure caused by the flow of hydromixture were examined using the computational fluid dynamics (CFD) method. The damage to an underground coal storage bunker due to stress distribution was examined using the finite element method (FEM). The results of the CFD numerical simulation were compared with the mathematical models.