共查询到19条相似文献,搜索用时 136 毫秒
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ANSYS在低温压力容器应力分析与优化设计中的应用 总被引:7,自引:0,他引:7
介绍了大型有限元软件ANSYS在低温压力容器典型应力分析(不连续区局部应力分析、热应力分析、接触应力分析、复合材料应力分析)与优化设计中的应用,论证了ANSYS作为低温压力容器应力分析与优化设计有效手段的实用性和可靠性,为低温压力容器的应力分析和优化设计找到了一条新途径。 相似文献
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A. S. Tabrizi M. Asadi G. Xie G. Lorenzini C. Biserni 《Journal of Engineering Thermophysics》2014,23(1):27-38
In this paper, the ball valve performance is numerically simulated using an unstructured CFD (Computational Fluid Dynamics) code based on the finite volume method. Navier-Stokes equations in addition to a transport equation for the vapor volume fraction were coupled in the RANS solver. Separation is modeled very well with a modification of turbulent viscosity. The results of CFD calculations of flow through a ball valve, based on the concept of experimental data, are described and analyzed. Comparison of the flow pattern at several opening angles is investigated. Pressure drop behind the ball valve and formation of the vortex flow downstream the valve section are also discussed. As the opening of the valve decreases, the vortices grow and cause higher pressure drop. In other words, more energy is lost due to these growing vortices. In general, the valve opening plays very important roles in the performance of a ball valve. 相似文献
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The experimental set-up of SMBI system in HL-2A and the detail structure of the molecular beam valve with cooling trap are shown in Fig.l. The valve used for producing hydrogen cluster jet is a solenoid valve S99 with a nozzle orifice of 0.2 mm diameter. The distance between the nozzle of the valve and the edge plasma is about 1.28 m. A liquid nitrogen cryogenic trap is applied for cooling the valve body and decreasing the working gas temperature. The hydrogen cluster jet used for the experiments is in fact a free jet. For real gases, the adiabatic expansion of gas through a nozzle into vacuum results in substantial cooling in the frame of the moving gas. Atoms or molecules that interact weakly at low temperature can form clusters as a result. Attractive forces between atoms can be hydrogen bonding, 相似文献
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The abnormal vibration of ball bearings lubricated with grease was studied. The test bearings were lubricated with three types of grease: Li soap/silicone oil grease, Na soap/mineral oil grease and Li soap/mineral oil grease. In the experiments, the axial-loaded ball bearings were operated at a constant rotational speed, and the vibration and the outer ring temperatures of the test bearings were measured. In addition, the shear stress and shear rate of the greases were measured by a rheometer. The experimental results showed that the abnormal vibration occurs on the test bearings lubricated with all three types of grease. Based on the experimental results, the generating mechanisms of the abnormal vibrations were discussed. From the discussions, it seems reasonable to conclude: (1) Li soap/silicone oil grease and Na soap/mineral oil grease both have a negative damping moment characteristic. The abnormal vibrations of the ball bearings lubricated with these greases are generated by the negative damping moment. (2) The abnormal vibration of the ball bearings lubricated with Li soap/mineral oil grease is generated by the decreasing positive damping moment of the grease due to the rising temperature. 相似文献
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液态固体电解质材料的离子电导率低,安全性问题在一定程度上限制了其发展与应用,而固体电解质材料在室温下具有很好的稳定性和高的离子电导率值,具有较好的应用前景.本文采用机械化学球磨法制备固体电解质Rb4Cu16I7Cl13粉末,探索制备工艺和球磨参数,对其晶体结构进行解析、观察粉体微观结构、通过交流阻抗谱及等效电路分析得到了离子电导率与活化能、并详细探讨其离子传导性能与晶体结构的关系以及化学成分稳定性进行研究.实验结果表明,在480 rpm转速下球磨6 h时可得到纯的固体电解质Rb4Cu16I7Cl13物相.粉体晶粒尺寸分布均匀,均在20 nm-400 nm之间,室温下固体电解质Rb4Cu16I7Cl13离子电导率可达到0.213 S/cm且活化能为0.087(9)eV.在真空干燥条件下存放5天和12天后观察了微观形貌和化学稳定性... 相似文献
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High-energy ball milling technique was successfully applied to calcinated lead zirconate titanate (PZT 60/40) powders. After 20?h of ball milling, large PZT particles were completely broken down, reducing its initial size in three orders of magnitude. Experimental results show a huge sinterability enhancement of the PZT powders by using this technique, achieving its maximum sintering rate at ~800°C. Relatively low densities (~91%) were achieved in stoichiometric samples, while in 3% lead excess samples sintered at 950°C for 30, 45, 60, 90 and 120?min using a fast firing process and a post-annealing treatment at 800°C for 4 h, densities of ~97% of the theoretical were achieved. PZT nanostructured ceramics prepared under optimized processing conditions (60?h of powder milling, 950°C of sintering temperature, 60?min of sintering time and a post-annealing process at 800°C during 4?h) show high dielectric constant (ε′) values (900) and low dielectric loss (tan?δ) at room temperature and a ferroelectric-paraelectric transition temperature at 375°C. 相似文献