The Experiment of Modulated Toroidal Current on HT-7 and HT-6M Tokamak

The Experiments of Modulated Toroidal Current were done on the HT-6M tokamak and HT-7 superconducting tokamak. The toroidal current was modulated by programming the Ohmic heating field. Modulation of the plasma current has been used successfully to suppress MHD activity in discharges near the density limit where large MHD m = 2 tearing modes were suppressed by sufficiently large plasma current oscillations. The improved Ohmic confinement phase was observed during modulating toroidal current (MTC) on the Hefei Tokamak-6M (HT-6M) and Hefei superconducting Tokamak-7 (HT-7). A toroidal frequency-modulated current, induced by a modulated loop voltage, was added on the plasma equilibrium current. The ratio of A.C. amplitude of plasma current to the main plasma current △Ip/Ip is about 12% ～ 30%. The different formats of the frequency-modulated toroidal current were compared.     

低压铸造ZL114A铝合金舱段壳体铸件工艺研究

以ZL114A合金舱段壳体铸件为研究对象,对其铸造工艺进行设计,并通过相关的数值模拟和工艺试验分析,确定了局部激冷及较高压差下凝固的舱段壳体低压铸件工艺方案和工艺参数。对低压铸造成形ZL114A合金舱段壳体铸件的窗口部位进行剖切取样测试分析,发现经固溶和双级时效处理后,其抗拉强度为349 MPa,屈服强度为288 MPa,伸长率为7.7%,达到了设计要求。     

鄂庄煤矿瓦斯异常区采煤工作面综合防尘技术

鄂庄煤矿通过采取优化回采工艺和调整通风系统增加风量、疏排工作面下隅角瓦斯等综合治理措施,实现了2707东工作面安全生产。     

基于UG的天线座模态与应力分析

根据工程实际应用需要,利用UG建模功能建立天线座转台的三维模型,通过NXNastran 进行有限元分析,并根据实际用边界条件和设定的频率范围进行频响分析,计算模态和应力分布。有限元分析结果表明,进行结构优化设计,提高了固有频率,使各项机械性能指标满足设计要求。     

反重力铸造数值模拟研究进展

结合国内外对反重力铸造数值模拟的研究工作和成果,介绍了反重力铸造充型、凝固、应力以及微观过程的数值模拟研究现状;提出反重力铸造数值模拟存在的问题,展望了这一领域进一步发展的方向。     

适流浇注系统在铝合金汽车转向泵铸造上的应用

通过应用数值模拟方法对汽车转向泵铸造充型过程出现的渣孔等缺陷进行分析,并应用适流浇注系统原则对铸件浇注系统进行了改进和优化,铸造的充型条件得到了改善,废品率由改进前的26.4％降至5.34％,验证了适流浇注系统对铝合金铸件的适用性.     

快速成形工艺在航空铝合金铸件试制中的应用

针对某航空厂采用传统砂型铸造试制盒子铝铸件存在的周期长、铸件表面质量差、尺寸精度难以满足要求及成品率低等问题,采用ProCAST进行了铸造工艺数值模拟优化,及选区激光烧结(SLS)直接制备其整体覆膜砂型/砂芯,在5天内完成了铸造工艺方案优化及2件铸件的浇注,得到了冶金质量好、几何尺寸合格、表面粗糙度(Ra)为6.3μm及尺寸精度为CT6～8级的复杂曲面盒子铝铸件,完全满足使用要求,实现了航空盒子铝铸件的精密砂型快速铸造。     

铝合金缸盖火花塞孔预铸及其金相组织

金属型重力铸造铝合金缸盖预铸火花塞孔，晶间距（SDAS）。预铸状态孔壁的SDAS明显减小，围的组织疏松。从铸件本体取样对比预铸前后孔壁的二次枝抗拉强度等力学性能提高，改善了火花塞周     

基于FLUENT的铝合金真空差压充型过程数值模拟

结合真空差压铸造特点,采用专业流体软件ANSYS Fluent中标准是k-ε模型对铝合金真空差压充型过程进行数值模拟,对某复杂薄壁铝合金壳体铸件进行了试制,并对模拟结果进行了验证与讨论.充型模拟结果表明,随着真空压力降低,真空度越高,铝合金液态金属的充型速度加快,充填形态更为平稳,无明显波动现象;在真空度为20 kPa时,铝合金铸件充型完整,卷气和裹气现象明显减少.实际结果与充型过程的模拟预测相符合.     

Removal of Particles by ICRF Cleaning in HT-7 Superconducting Tokamak

1. IntroductionThe tokamak is a magnetically confined fusion device, Which demands ultra-vacuum and low impuritylevel for the plasma discharge. At the same time, therecycling of the working gas including its isotopesmust be decreased in favor of long pulse plasma discharge. For a larger superconducting tokamak of thefuture with a high power and a long pulse plasmadischarge, the recycling must be very low and theimpurity needs to be removed quickly.For decreasing the impurity content in the de…