A traditional hydrocyclone can only generate two products with different size fractions after one classification, which does not meet the fine classification requirements for narrow size fractions. In order to achieve the fine classification, a multi-product hydrocyclone with double-overflow-pipe structure was designed in this study. In this work, numerical simulation and experimental test methods were used to study the internal flow field characteristics and distribution characteristics of the product size fraction. The simulation results showed that in contrast with the traditional single overflow pipe, there were two turns in the internal axial velocity direction of the hydrocyclone with the double-overflow-pipe structure. Meanwhile, the influence rule of the diameter of the underflow outlet on the flow field characteristics was obtained through numerical simulation. From the test, five products with different size fractions were obtained after one classification and the influence rule of the diameter of the underflow outlet on the size fraction distribution of multi-products was also obtained. This work provides a feasible research idea for obtaining the fine classification of multiple products.

In view of the difficulty of traditional hydrocyclones to meet the requirements of fine classification, a double-overflow three-product (internal overflow, external overflow and underflow) hydrocyclone was designed in this study. Numerical simulation and experimental research methods were used to investigate the effects of double-overflow flow field characteristics and structural parameters (i.e., internal vortex finder diameter and insertion depth) on separation performance. The research results showed that the larger the diameter of the internal vortex finder, the greater the overflow yield and the larger the cut size. The finest internal overflow product can be obtained when the internal vortex finder is 30 mm longer than the external vortex finder. The separation efficiency is highest when the internal vortex finder is 30 mm shorter than the external vortex finder.

Aluminum alloy 6082-T6 is an important material for manufacturing the outer skin of high-speed trains, and laser shock forming can realize the rapid forming of complex-shaped plates. In order to improve the efficiency of the simulation modeling of laser shock forming for aluminum alloy 6082-T6, Python scripting language was used for the secondary development of Abaqus. A plugin was utilized to simulate and analyze the laser shock forming process of aluminum alloy 6082-T6. The coordinates of the plate after laser impact molding were measured using a coordinate measuring machine to calculate the arc bow height of the plate. The accuracy of the simulation model was verified by comparing with the simulation results. The deformation characteristics of plastic strain and arc height of aluminum alloy 6082-T6 under different laser process parameters were analyzed. The simulation plugin has a concise interface, high operability, and accurate results with the other parameters unchanged. When the laser energy is 5 J, 6 J, and 7 J, the corresponding arc heights are 5.9 mm, 6.6 mm, and 7.2 mm, respectively. As the thickness of the sheet increases, the deformation changes from concave at 1 mm to convex at 2 mm, 3 mm, 4 mm, and 5 mm. As the spot size increases from 1 mm to 5 mm, the transmission mode of the shock wave gradually changes from spherical wave to planar wave, and the arc height of the sheet increases from 4.6 mm to 8.2 mm. With the increase in the spot overlap rate, the impact area accumulates residual stress, and the arc height of the sheet is 5.7 mm, 6.6 mm, 7.3 mm, and 8.5 mm, respectively. The secondary development of ABAQUS 2021 using Python 3.6 scripting language has improved the efficiency of simulation modeling and provided reference for rapidly predicting the deformation characteristics of aluminum alloy 6082-T6 under different laser process parameters.

Double-coil inductive displacement transducer is a non-contact type high-precision displacement measurement element, which is widely used in industrial manufacturing and large power equipment systems. Since the inductive displacement transducer has a parasitic capacitance, the frequency of the excitation signal has a great influence on the performance that has been little studied so far. In this paper, the method of determining the optimal excitation frequency of double-coil inductive displacement transducer is studied. The working principle and characteristics were analyzed, a signal conditioning circuit was proposed and a circuit simulation model was established. According to the simulation results, the influence law of the frequency of excitation signal on the double-coil inductive displacement transducer is obtained. The effect of frequency on the displacement transducer was analyzed in five aspects: frequency characteristics, output signal, sensitivity, the residual voltage at zero and linearity. Finally, the effectiveness of the simulation results was verified through experiments. The simulation and experiment show that the proposed signal conditioning circuit can realize the demodulation of the double-coil inductive displacement transducer signal. Taking DIPT14 displacement transducer as the research object, the frequency of excitation signal has influence on the sensitivity, residual voltage at zero and linearity. When the frequency is low, the parasitic parameters have little effect on the performance of the transducer and can be ignored. However, when the frequency is high, the parasitic parameter has a great influence on the performance of the transducer. The method presented in this paper is of great significance for the study of the characteristics, signal conditioning circuit and the determination of the optimal frequency of the excitation source of double-coil inductive displacement transducers.

To overcome limitations of current designs of hydraulic supports based on conventional physical prototype, we propose a virtual prototyping based design mode for hydraulic supports. In this study, a 3D numerical model of hydraulic support was established by numerical simulations and stress distributions on hydraulic support were investigated. Also, motion simulation and interference detection of the working process of hydraulic supports were involved. The results indicated that the proposed hydraulic support based virtual prototyping is viable and the simulation results are consistent with practical working conditions of hydraulic supports. Indeed, virtual prototyping can improve the design method and reduce the design period. This study facilitates optimized design of hydraulic supports, thus providing references for industrial applications.