潘三矿立井揭煤瓦斯抽采模拟研究

瓦斯抽采对于立井揭突出煤层起到重要的作用,准确的确定钻孔瓦斯有效抽采半径和合理的在待抽煤层中布置抽采钻场对煤层消突具有关键性作用。基于多孔介质中流体流动达西定律理论,采用COMSOL Multiphysics软件对该煤层瓦斯抽采进行了模拟。模拟结果表明,此煤层的瓦斯有效抽采半径为3 m,随着抽采时间的增加,煤层瓦斯压力逐渐的降低,但降低的速率会逐渐的减小。瓦斯抽采30天后,其残余的瓦斯压力为0．18 MPa ,这与现场实测的最大残余瓦斯压力0．2 MPa相接近,这说明了模型的可信性,其模拟结果可为瓦斯抽采设计提供参考。     

基于分布式辅助散流接地网的天然气管道过电压防护

由于共建城市地下走廊,输电线路常与天然气管道并行敷设,当输电线路遭受雷击时,通过杆塔接地网向附近土壤散流会导致邻近天然气管道损耗的问题。为了研究雷击输电线路对天然气管道的具体影响,本文通过COMSOL Multiphysics仿真软件建立临近管道处杆塔辅助接地网散流模型,对比分析了杆塔辅助接地网的外延长度、面积、敷设方向、连接线数量以及土壤电阻率等因素对杆塔接地电阻和天然气管道电压峰值的影响,进而提出了基于杆塔辅助地网的管道过电压防护方案。仿真结果表明:减小土壤电阻率、增加辅助地网外延长度、面积和连线数量会降低天然气管道感应电压峰值;135°敷设辅助地网对天然气管道感应电压峰值防护效果最优。本文研究结论可为城市综合能源走廊建设提供参考。     

UN核芯TRISO包覆燃料颗粒性能分析

为分析致密热解碳层、内压等因素对TRISO包覆燃料颗粒热-力学性能的影响,基于多物理场耦合软件COMSOL建立了以UN为核芯的TRISO包覆燃料颗粒三维热-力学耦合模型,并通过IAEA CRP-6基准题进行了验证。利用本文模型对稳态运行及反应性引入事故（RIA）工况下典型TRISO包覆燃料颗粒的性能进行了分析,结果表明,正常运行工况下SiC层能维持结构完整性,但IPyC层存在失效风险,需进一步优化TRISO包覆燃料颗粒的设计方案,而RIA工况下热膨胀是造成TRISO包覆燃料颗粒发生结构失效的主要原因。该模型能对轻水堆运行环境下的TRISO包覆燃料颗粒进行复杂的多物理场耦合性能分析,为进一步优化FCM燃料元件设计打下基础。     

高折射率镀膜聚合物波导传感器的制备

为了提高利用倏逝波传感的光纤传感器的灵敏度问题,仿真并验证了一种基于高折射率镀膜的光纤传感器.首先两根光纤之间利用激光诱导波导自行成技术形成聚合物波导,并在波导表面镀上一层高折射率Ta2O5薄膜以增强波导表面倏逝波强度,从而增加传感器灵敏度.根据聚合物波导制备结果,使用COMSOL Multiphysics?软件对Ta...     

Thermal management and desorption modeling of a cryo-adsorbent hydrogen storage system

Adsorbent based hydrogen storage systems using activated carbon or metal organic framework (MOF) materials are among the most promising material based hydrogen storage systems. In this effort, a complete 3-D discharge model to simulate extraction of hydrogen from the storage bed for fuel cell operation is developed. The desorption process is endothermic and the heating requirement is met by a heating element which includes a helical coil and a central longitudinal rod placed inside the bed. Since thermal conductivity of adsorbent bed plays a crucial role in determining the temperature distribution, simulations were performed to find an optimum conductivity range that can facilitate maximum extraction of hydrogen from the bed along with a fairly uniform bed temperature distribution. Finally, storage system designs including the adsorbent bed and heating system for two adsorbents – an activated carbon (AX-21) and a MOF material (MOF-5) – are presented.     

基于有限元法的离子迁移谱电场数值模拟研究

传统线性离子迁移谱中漂移管电场的均匀性是离子迁移谱性能的主要影响因素之一。本研究利用COMSOL Multiphysics仿真平台,基于有限元法对线性漂移管的内电场进行数学物理建模及数值模拟分析,给出建模方法和均匀电场的标准,研究了电极厚度、绝缘环厚度、漂移管内径以及漂移管外部电场等因素对漂移管内电场的影响,旨在通过模拟结果优化离子迁移谱仪器设计,提高离子迁移谱的性能,为设计者提供参考。     

电涡流测功器低速检测时最佳匹配问题的研究

针对矿用轻型胶轮车低速检测时底盘输出功率与电涡流测功器外特性曲线不匹配的问题进行研究,建立胶轮车行驶阻力功率和电涡流测功器吸收功率的数学模型,对电涡流测功器进行参数化分析并获得外特性曲线,利用COMSOL软件对不同转盘材料进行电磁模拟仿真。分析了气隙长度、定子极对数、励磁电流和转盘材料对电涡流测功器吸收功率和临界转速的影响。结果表明:改变电涡流测功器定子极对数和使用不同转盘材料对其外特性曲线有较显著的影响。     

基于COMSOL Multiphyslc的煤层甲烷拟稳态吸附一运移数值模拟

由于煤层甲烷在煤岩体中的运移过程及其复杂，因此用来描述其运移的数学模型常常是高阶非线性的偏微分方程，为了能更好地解决此类问题，采用多重物理量数值模拟软件COMSOLMultiphysic对所建的拟稳态运移模型进行了模拟求解的研究。结果表明用该软件模拟的压力和浓度动态曲线更符合实际情况，而且可以用动态可视化模块来模拟压降过程。     

Green synthesis of novel lanthanum doped copper oxide nanoparticles for photocatalytic application: Correlation between experiment and COMSOL simulation

Treatment of waste water via photocatalysis is one of the most effective, economical and environment friendly process. In this study, green method (leaf extract of Citrus Medica Linn.) is used to synthesize pure and lanthanum (La)-(1,2 & 3 wt%) doped copper oxide nanoparticles (CuO-NPs). Different characterization techniques such as XRD, SEM, EDS, UV/VIS, PL and FTIR are utilized to investigate their physical, chemical, optical and structural properties. The synthesized material is used as photocatalyst for degradation of methylene blue (MB) dye. Interestingly, the La doped CuO-NPs have exhibited unique results. Variation in dopant concentration reduces the particle size (40.82 ± 0.04 nm to 31.89 ± 0.02 nm) and band gap of material shifts towards visible region (3.03 eV–2.71 eV). During photocatalysis, doping reduces the electron-hole pair recombination rate which makes it a potential photocatalyst. Maximum degradation efficiency of 84% is observed in 150 min for 2% La doped CuO-NPs which reveals that 2% La doping is optimal. Further increase in dopant concentration increases band gap, therefore, degradation efficiency drops to 75%. Simulation of this work is carried out using COMSOL Multiphysics 5.3a Licensed version. A 2D model is constructed and CuO-NPs is considered as photocatalyst in order to correlate simulated and experimental photocatalytic degradation of MB and rhodamine B (RhB) dye. Comparative analysis of rate constants revealed that the trend given by simulation is very close to the experimental observations.     

基于有限元法的码垛机器人模态分析

介绍了码垛机器人的设计原理和总体结构。利用有限元分析软件COMSOL,以模态分析为理论基础,建立了码垛机器人的有限元模型,选择了码垛机器人3种典型的位姿,并对各阶固有频率进行了分析,得出各阶固有频率下的模态振型。结果表明:各种位姿的机器人的前六阶固有频率集中在15~130 Hz之间;小臂和前后大臂是主要的动态特性影响因素,可以通过适当的增加壁厚或者提高材料的刚度来进行改进;整个机器人的固有频率较低,可以通过优化手臂平行四边形机构来提高整体结构的刚度,从而提高机器的固有频率,改善其振动特性.