ABSTRACT Dehulling of barnyard millet ( Echinochloa esculenta ) is an essential process in enhancing the nutritional value and utilization of millets. The main challenge lying behind dehulling of barnyard millet is its small size and hard aleurone layer resulting in poor dehulling and breakage ratio. Since the dehulling process involves complex interactions between individual grains and machine components that are difficult to observe experimentally, the discrete element method (DEM) was employed to simulate particle dynamics and contact forces during the process focussing on the effect of concave clearance (2, 4, 6 mm) and roller operating speed (1600, 1800, 2000 rpm) of the abrasive roller by applying Hertz‐Mindlin no slip contact model. Optimum clearance and speed combination were identified to achieve effective hull removal with lesser grain breakage based on the compressive force occurring in the system. Model validation was performed to study the efficacy of DEM in simulating the dehulling process by comparing the results from experiment and simulation. An optimal condition of 4 mm concave clearance and 1800 rpm resulted in a maximum dehulling efficiency of 70.4% with a broken grain percentage of 12.4%. The DEM predictions showed good agreement with experimental results ( R 2 = 0.825), confirming the reliability of the model. The findings demonstrate the potential of DEM as a tool for optimizing operating parameters and improving the design of millet dehulling systems. Hence, DEM proves to be a reliable tool for optimizing operating parameters and supporting the design and improvement of processing systems.
Anusuya et al. (2026) studied this question.