Papers by Author: Yao Huang

Abstract: Moldflow software is used to analyze the warping of the PMMA sheet in this article. It is shown that density of bar-defects, cross-section shape of bar-defects and sectional dimension of bar defects influence the warping in different level. The relationship of bar-defects and warping is amply analyzed. As a result, it is found that cross-section shape of bar-defects and sectional dimension of bar defects have more influence to warping, especially in the vertical direction of the surface. At last, some feasible method is put forward to decrease the warping.

Abstract: Molecular dynamics (MD) techniques were employed to simulate the diffusion properties of molecular hydrogen on all-silica ZSM-5 zeolite. The results indicated that in the temperature range of 77-293K and the pressure range of 14-3360 kPa, the diffusion coefficients are found to range from 1.2×10^-9 m²/s to 3.8×10^-7 m²/s, and increase with increasing temperature, and decrease with increasing pressure. The activated energy for hydrogen diffusion determined from the simulation is pressure-dependent. The diffusion of the molecular hydrogen in all-silica ZSM-5 zeolite channels is anisotropic duo to the increase of the temperature. The diffusion coefficients in straight channels are higher than that in zigzag channels. The difference results from the structural difference of the two channels and the different loadings of hydrogen. Keywords: Hydrogen; Zeolite; Diffusion; Molecular-dynamics simulation

Abstract: In this paper, the distribution and variation trend of temperature and velocity fields were obtained by numerical simulation of the casting process of shell die casting. According to the results of the numerical simulation, the die casting technology was optimized. The sound castings were produced. It was verified that shrinkage cavity and porosity could be reduced by increasing injected pressure and decreasing pouring and mould temperatures. The reliability of numerical simulation of die casting process was proved. In addition, the qualified products were obtained on the basis of the optimized die-casting parameters from the simulation results.