Observation of non-chemical equilibrium effect on Ar-CO2-H2 thermal plasma model by changing pressure

The authors developed a two-dimensional one-temperature chemical non-equilibrium (1T-NCE) model of Ar-CO₂-H₂ inductively coupled thermal plasmas (ICTP) to investigate the effect of pressure variation. The basic concept of one-temperature model is the assumption and treatment of the same energy conservation equation for electrons and heavy particles. The energy conservation equations consider reaction heat effects and energy transfer among the species produced as well as enthalpy flow resulting from diffusion. Assuming twenty two (22) different particles in this model and by solving mass conservation equations for each particle, considering diffusion, convection and net production terms resulting from hundred and ninety eight (198) chemical reactions, chemical non-equilibrium effects were taken into account. Transport and thermodynamic properties of Ar-CO₂-H₂ thermal plasmas were self-consistently calculated using the first-order approximation of the Chapman-Enskog method. Finally results obtained at atmospheric pressure (760 Torr) and at reduced pressure (500, 300 Torr) were compared with results from one-temperature chemical equilibrium (1T-CE) model. And of course, this comparison supported discussion of chemical non-equilibrium effects in the inductively coupled thermal plasmas (ICTP).     

射频热等离子体制备球形氧化铝粉末的数值模拟及实验研究

研究粉末颗粒在热等离子体(ICTP)中的行为可以为射频等离子体制备球形粉末工艺过程的优化提供参考。首先, 利用FLUENT软件对具有不同粒径分布的氧化铝粉末颗粒在射频热等离子体中的运动轨迹及加热历程进行了数值模拟; 然后, 根据模拟结果所确定的实验参数范围进行了射频热等离子体粉末球化实验, 并将实验测量与数值模拟的结果相结合, 研究了输入功率、送粉速率等参数的改变对具有不同粒径分布的氧化铝粉末球化效果的影响。研究结果表明: 粒径较小的氧化铝粉末颗粒在飞行过程中可以从等离子体内吸收更多的热量, 因此能够被充分加热至完全熔化; 增加系统输入功率、降低送粉速率均能提高单位质量的颗粒从等离子体中获得的能量, 从而在一定程度上提升氧化铝粉末的球化率。     

国际塑性加工会议(ICTP)的回顾与展望

国际塑性加工会议(International Conference on Technology of Plasticity,简称ICTP)是塑性加工领域规模最大、水平最高、最具权威性的国际会议,被誉为塑性加工界的"奥林匹克",始创于1984年。自第5届(1996年)起由日本塑性加工学会颁发了精锻研究与开发国际奖,首届获奖人为日本工藤英明教授和美国T.Altan教授。至今,ICTP已经在包括中国在内的世界各国举办了8届。本文对前8届盛会进行回顾,从历届会议的规模、与会人数以及举办特色等多方面进行分析和比较,折射国际塑性加工领域24年来的发展历程和取得的成就,并对今后塑性加工的发展进行了展望。     

基于能量感知的无线传感器网络CT P路由算法

为了增强无线传感器网络的动态适应性和实现数据包的最优传输,根据CTP算法的原理,使用NesC语言在TinyOS 2．x下设计改进路由协议ICTP。该协议采用传输期望值指引路由包和数据包进行传输,并在数据包传输过程中考虑下一跳邻居节点的剩余能量以实现动态均衡网络能耗。通过TOSSIM仿真实验表明,改进后的ICTP能够有效减少传输时延,延长网络寿命,提高网络能量均衡。