Papers by Author: Yi Lun Liu

Abstract: The angle of repose of sand pile compose of cylindrical particles was extensively studied using the discrete element method (DEM). The Multi-element model was selected for representing cylindrical particle and the effects of shape of granular on angle of repose were studied. The results show that the angle of repose of cylindrical particles is obviously larger than that of spherical particles. Meanwhile, the shape factor (length-width ratio) of cylindrical granular has a great influence on the angle of repose of granular system. As studied in this paper, the angle of repose increases with the increasing of length-width ratio. Cautious should be taken when choosing a reasonable particle model for more precise DEM results.

Abstract: This paper introduces working principle of screw oscillating hydraulic cylinder. Structure parameters and process parameters influence on mechanical efficiency is analyzed, simultaneously, structure parameters and process parameters influence on volumetric efficiency is also analyzed. the maximum mechanical efficiency and optimal spiral angle are acquired. Total transmission efficiency model is established. Transmission efficiency experimental test is carried out, experiment test efficiency is basically in accordance with calculated efficiency.

Abstract: Crushing is the necessary process of solid mineral resources development and utilization, and the technology level of grinding equipment is closely related with the development and utilization of mineral resource. In this paper, the main grinding equipments such as jaw crusher, cone crusher and ball grinding mill, are comprehensively summarized, especially on the technology’s development, the existing problems and development’s direction. In addition, the prospect and direction of the grinding technology are put forward in the view of industry.

Abstract: According to actual structure parameters and the technological parameters in an aluminum hot rolling production line, consider the rolling of metal plastic deformation heat, the contact surface heat conductivity, friction heat effect on the rolled piece and the roller heat transfer, use finite element analysis software MSC.Marc to build thermo-mechanical coupled finite element simulation model about aluminum hot rolling frame F2. Analyzing different rolling process parameters on the influence of the temperature field distribution regularity, and by adjusting the rolled-piece technology parameters to control temperature distribution, so as to achieve the purpose of improving product quality, and to provide theoretical basis for production of aluminum strip.

Abstract: In order to obtain the lubricating capabilityof screw rotary cylinder, its structural design and operation principle were introduced. Seven screw pairs with different radial clearance were designed. The models were built by Pro/E. Structure mesh was generated by using Gambit. Based on laminar flow model and SIMPLE algorithm, the interior flow field in different radial clearances and the same radial clearance at different inlet pressure were numerically simulated and analyzed with Fluent. The relationship of loading force, stiffness, maximum temperature, flow rate and radial clearance were obtained. Simulation results show that the performance of oil lubricated screw pair is the best at the radial clearance of 0.10 mm. At the same radial clearance, when back pressure is constant, with inlet pressure increasing, loading force, stiffness, flow rate and maximum temperature increase completely.

Abstract: This paper introduces the structural design and operation principle of rotary hydraulic cylinder. Seven spiral flows with different clearance were designed. The models were built by Pro/E. Structure meshes were generated by using Gambit. Based on laminar model and SIMPLE algorithm, the interior flow field in different clearance and the same clearance at different rotation rate were numerically simulated and analyzed with Fluent. The relationship of clearance, rotation rate and viscous force, maximum temperature, stiffness, flow rate were obtained. Simulation results show that clearance’s influence on internal leakage is greater than rotation rate, at the clearance of 0.05mm～0.10mm is relatively suitable.