Molecular Simulation of Adsorption Mechanism of Silicone Rubber Interfacial Systems

2014 ◽  
Vol 1023 ◽  
pp. 15-18
Author(s):  
Qiang Yang ◽  
Xiao Ping Wen ◽  
Chao Ming Sun ◽  
Guang Ping Tang

The adsorption mechanisms of silicone rubber (SR)-stainless steel (SS) interfacial system and silicone rubber-HMX interfacial system were studied by molecular simulation method in the present paper. The molecular simulation results revealed that silicone rubber-stainless steel interface has obvious adsorption effect, while silicone rubber-HMX interface has certain adsorption effect. The systematic potential energy calculation results revealed that coulomb interaction and van de waals interaction might be the major microscopic adsorption mechanism for silicone rubber-stainless steel interfacial system and silicone rubber-HMX interfacial system.

2013 ◽  
Vol 781-784 ◽  
pp. 576-579
Author(s):  
Xiu Juan Wang ◽  
Xiu Ting Zheng ◽  
Meng Song ◽  
Xiu Ying Zhao ◽  
Si Zhu Wu

This work studied the influence of different molecular structure of polycarbonate on its properties. Different types of polycarbonate molecular chain models were built by molecular simulation method. By combining experimental and molecular dynamic simulation results, it is concluded that the polycarbonate-OQ2720 has better thermal stability, mechanical properties and optical performance, which is a better choice for aviation materials and manufacturing process.


2014 ◽  
Vol 556-562 ◽  
pp. 441-444
Author(s):  
Xiu Juan Wang ◽  
Xiu Ting Zheng ◽  
Wei Zheng ◽  
Si Zhu Wu

The influence of molecular structure of polycarbonate on performance was systematically investigated by both experiment and molecular simulation. Different types of polycarbonate molecular chain models were built and analyzed by molecular simulation method. By combining experimental and simulation results, it is concluded that the polycarbonate-OQ2720 has better thermal stability, mechanical properties and optical performance, which is a better choice for aviation materials and manufacturing process.


This paper studies the butt welded joint of SUS316L stainless steel. The butt joint is not beveled, has a gap and is welded in one pass by MIG welding process. First, the welding parameters of this weld are determined through calculation and test welding for the butt joint of two plates of 3 mm in thickness. Then these welding parameters are used as input data to calculate and determine the temperature field by two methods: the calculation method based on the theory of heat transfer process and the numerical simulation method of welding processes that relies on SYSWELD software on the basis of the finite element method. The calculation results of the two methods were compared with each other and tested by experiment to show the reliability of calculation and simulation results.


2021 ◽  
pp. 174425912110171
Author(s):  
Hideya Yamamoto ◽  
Daisuke Ogura

Vacuum insulation panels (VIPs) with a glass-fiber core has been considered to be difficult to operate for a long period of time, such as for building applications, because the thermal conductivity rises rapidly as the pressure increases. However, glass-fiber-core VIPs contain a material called a getter that continuously adsorbs permeated gas, and a theoretical model that considers the properties of the getter has not yet been developed. In this paper, the gas-adsorption mechanism by getters was investigated and a long-term-performance prediction model that considers the temperature dependence was proposed. Some gases were not adsorbed by the getter in the VIPs; however, a model was proposed that takes into account the non-absorbed gases by applying partial pressure to the adsorption isotherm in advance. The long-term performance of VIPs with different areas and volumes was compared with the measured values, and the validity of the calculation results was confirmed. These results show that the long-term performance of VIPs of different sizes can be accurately predicted when the getter performance is well understood.


2021 ◽  
Author(s):  
Chaoyue Xie ◽  
Yunlan Sun ◽  
Baozhong Zhu ◽  
Weiyi Song ◽  
Minggao Xu

Activated carbon-supported iron-based catalysts (FexOy/AC) show excellent deNOx efficiency. However, the specific adsorption mechanisms of NH3, NO, and O2 molecules on their surfaces are still unknown. In this study, the...


2015 ◽  
Vol 1092-1093 ◽  
pp. 356-361
Author(s):  
Peng Fei Zhang ◽  
Lian Guang Liu

With the application and development of Power Electronics, HVDC is applied more widely China. However, HVDC system has the possibilities to cause subsynchronous torsional vibration interaction with turbine generator shaft mechanical system. This paper simply introduces the mechanism, analytical methods and suppression measures of subsynchronous oscillation. Then it establishes a power plant model in islanding model using PSCAD, and analyzes the effects of the number and output of generators to SSO, and verifies the effect of SEDC and SSDC using time-domain simulation method. Simulation results show that the more number and output of generators is detrimental to the stable convergence of subsynchronous oscillation, and SEDC、SSDC can restrain unstable SSO, avoid divergence of SSO, ensure the generators and system operate safely and stably


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2199
Author(s):  
Khadija Asif ◽  
Serene Sow Mun Lock ◽  
Syed Ali Ammar Taqvi ◽  
Norwahyu Jusoh ◽  
Chung Loong Yiin ◽  
...  

Polysulfone-based mixed matrix membranes (MMMs) incorporated with silica nanoparticles are a new generation material under ongoing research and development for gas separation. However, the attributes of a better-performing MMM cannot be precisely studied under experimental conditions. Thus, it requires an atomistic scale study to elucidate the separation performance of silica/polysulfone MMMs. As most of the research work and empirical models for gas transport properties have been limited to pure gas, a computational framework for molecular simulation is required to study the mixed gas transport properties in silica/polysulfone MMMs to reflect real membrane separation. In this work, Monte Carlo (MC) and molecular dynamics (MD) simulations were employed to study the solubility and diffusivity of CO2/CH4 with varying gas concentrations (i.e., 30% CO2/CH4, 50% CO2/CH4, and 70% CO2/CH4) and silica content (i.e., 15–30 wt.%). The accuracy of the simulated structures was validated with published literature, followed by the study of the gas transport properties at 308.15 K and 1 atm. Simulation results concluded an increase in the free volume with an increasing weight percentage of silica. It was also found that pure gas consistently exhibited higher gas transport properties when compared to mixed gas conditions. The results also showed a competitive gas transport performance for mixed gases, which is more apparent when CO2 increases. In this context, an increment in the permeation was observed for mixed gas with increasing gas concentrations (i.e., 70% CO2/CH4 > 50% CO2/CH4 > 30% CO2/CH4). The diffusivity, solubility, and permeability of the mixed gases were consistently increasing until 25 wt.%, followed by a decrease for 30 wt.% of silica. An empirical model based on a parallel resistance approach was developed by incorporating mathematical formulations for solubility and permeability. The model results were compared with simulation results to quantify the effect of mixed gas transport, which showed an 18% and 15% percentage error for the permeability and solubility, respectively, in comparison to the simulation data. This study provides a basis for future understanding of MMMs using molecular simulations and modeling techniques for mixed gas conditions that demonstrate real membrane separation.


2012 ◽  
Vol 503-504 ◽  
pp. 731-734
Author(s):  
Xiao Xu Liu ◽  
Min Chen ◽  
Ai Hua Tang

The engine model with 4 cylinders is built by SolidWorks, the kinematics and dynamics simulations of the engine virtual prototype are done by COSMOSMotion, the results of kinematics simulation are checked, there are very small errors between the simulation results and the calculation results according to formulas. The mainly results of dynamics simulation are given. The simulation result consists with the parameters of the engine.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Zhengzhi Wang ◽  
Chunling Zhu

In view of the rotor icing problems, the influence of centrifugal force on rotor blade icing is investigated. A numerical simulation method of three-dimensional rotor blade icing is presented. Body-fitted grids around the rotor blade are generated using overlapping grid technology and rotor flow field characteristics are obtained by solving N-S equations. According to Eulerian two-phase flow, the droplet trajectories are calculated and droplet impingement characteristics are obtained. The mass and energy conservation equations of ice accretion model are established and a new calculation method of runback water mass based on shear stress and centrifugal force is proposed to simulate water flow and ice shape. The calculation results are compared with available experimental results in order to verify the correctness of the numerical simulation method. The influence of centrifugal force on rotor icing is calculated. The results show that the flow direction and distribution of liquid water on rotor surfaces change under the action of centrifugal force, which lead to the increasing of icing at the stagnation point and the decreasing of icing on both frozen limitations.


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