Study On The Transport Characteristics Of Bulk Coal Particles Within A Scraper Conveyor Based On Sph

Given the characteristics of large deformation, strong nonlinearity, and free-surface evolution exhibited by bulk coal during coal mining operations—such as scraper conveying and free-fall deposition—conventional mesh-based numerical methods are prone to mesh distortion, difficulties in boundary tracking, and limited predictive accuracy. To address these issues, this study employs the smoothed particle hydrodynamics (SPH) method and establishes a continuum mechanics–based numerical model for bulk coal by incorporating the Drucker–Prager yield criterion and an elastoplastic constitutive relationship. First, direct shear tests are conducted to obtain key parameters, including the friction angle, shear modulus, and cohesion, for coal particles with different particle-size conditions. Experimental rigs and corresponding SPH numerical models are then developed for two representative scenarios, namely scraper conveying and free-fall coal piling, to systematically investigate the effects of coal-flow height, scraper spacing, and particle size on particle transport behavior, stress-field distribution, and free-surface morphology evolution. Comparisons with experimental results indicate that the SPH simulations agree well with observations in terms of motion patterns, free-surface profiles, and overall macroscopic response trends, demonstrating that the proposed approach can effectively capture the flow mechanisms of bulk coal particles under boundary constraints and yielding effects. The findings provide a theoretical basis and practical reference for dynamic stability assessment and structural parameter optimization of underground bulk-material conveying processes.