一种能应用于气液两相流的新型稳流阀设计（英文）

流量与压降的波动广泛存在于气液两相流中,并且会对设备造成严重的疲劳损伤甚至导致设备失效,因此降低气液两相流中的流量波动与压降差波动是有必要的。首先对中国古书《岭外外答》中记载的一种液压装置进行了理论分析,该装置主要功能是实现稳流效果,并且只有合适的压差才能使其正常工作;利用欧拉方程与伯努利方程对整个装置的流场与工作原理进行了系统的分析,在分析过程中考虑了流体不同流态(层流、湍流、气液两相流等)对模型的影响,并根据建好的模型应用FLUENT软件对流场进行了仿真模拟。在此装置基础上,论证通过对其管径比以及结构的进一步优化以及植入传感模块可设计出一种能应用到气液两相流的稳流装置。     

高压气液脉冲两相流运动学建模与仿真分析

提出一种通过气路和液路交替通入高压脉冲流体,形成两相振荡流对液压系统管道内壁的污染物进行去除的气液耦合激振方式。设计了气液脉冲试验系统,建立了高压气液脉冲两相流动力学模型,利用ANSYS中的FLUENT模块进行了仿真分析。采用κ-ε二方程湍流模型,气液两相流模型采用VOF模型,用SIMPLE算法对双流体控制方程组进行迭代求解,对气液脉冲两相流的压力场、速度场及流态进行了分析,为气液两相流激振的可控性提供了参考。     

W-Cu液相烧结体系致密化行为的模拟

基于流体流动模型和液相烧结作用力模型,对液相烧结第一阶段中(液相生成与固相颗粒重排阶段)液相Cu对固相W颗粒的润湿情况及颗粒的重排和密实化行为进行模拟。本模型包含Navier-Stokes(N-S)方程、区分气-液两相流的VOF方程及颗粒所受作用力(毛细力和黏性力)方程。使用二维非定常分离隐式PISO算法求解N-S方程,描述流体流动行为;求解VOF方程以区分气-液两相流;根据颗粒所受作用力编制颗粒运动自定义程序,控制颗粒运动,描述固相颗粒在毛细力牵引及黏性力共同作用下的运动。分析烧结过程液相对固相颗粒的润湿行为及液相烧结第一阶段密实化规律。探讨润湿角、颗粒间距对毛细力大小的影响,并结合具体烧结模型研究烧结体系颗粒尺寸对密实化速度的影响及不同初始液固比与烧结体系最终孔隙率的关系。最终将模拟结果与理论分析结果进行对比,两者基本一致。     

高温气—固两相流对合金冲刷—氧化联合作用的实…

研究发展了模拟高温气－固两相流对合金冲刷－氧化联合侵蚀作用的实验室试验技术与装置。与利用高速旋转的试样与经高温流态化的固相颗粒作相对运动而产生冲刷－氧化作用。试验装置的最高温度可达９５０℃，试样相对气－固两相流的最大运动速度为１５ｍ／ｓ，两相流中固体颗粒含量可在１０％－６０ｖｏｌ％范围催调节。利用本装置对３１０不锈钢和ＨＫ４０合金的高温冲刷－氧化行为进行了测试，发现两种合金都表现为冲刷增强氧化行为     

高炉冷却壁冷却水管内液固两相流强化传热实验研究

针对高炉冷却壁管内污垢沉积而导致传热效率低的问题,提出在高炉冷却壁管内加入固相颗粒以形成液固两相流,在防止污垢的沉积及清洗污垢的同时,增加流体的扰动强化管内对流传热.对液固两相流和单相流的传热性能进行了对比实验.结果表明,由于固相颗粒的扰动和剪切效应,不仅可以强化管内传热,而且也可以在线清洗管内污垢,在流速为2 m/s,固相体积分数为3.5%～5.0%、固相粒径为2～3 mm的范围内,与单相流相比,液固两相流的传热系数提高了20%～45%.实验结果为液固两相流的工业应用提供了基础.     

气液两相流管道内腐蚀与防护研究

气液两相流管道内腐蚀现象普遍存在。通过对气液两相流管道内腐蚀进行分类,综述了气液两相流管道中CO2腐蚀、H2S腐蚀和CO2/H2S共同作用腐蚀、冲刷腐蚀等及其影响因素,分析了气液两相流管道内腐蚀特征,归纳了气液两相流管道内腐蚀防腐方法,提出了防止气液两相流管道内腐蚀的一些建议,以期减少管道内腐蚀事故和提高经济效益,为油田及相关企业提供借鉴。     

一种新型的并联式气-液复合传动增压装置

介绍了一种并联式双作用双级气-液复合传动增压装置的工作原理,给出了其输出流量与输出压力的计算公式.该装置采用并联式主被动活塞直联结构,能有效避免串联式装置的气液两相容易混合的问题,技术性能较为完善.     

圆形微通道结构多相流流动形态试验及数值模拟研究北大核心

利用高速摄像观测系统对不同挡板结构的圆形微通道结构进行全流场流动显示实验。通过对重力影响、气液流量比、流动方向等变量的控制进行多相流流动形态分析;在此基础上进行数值模拟研究,得到气液多相流流动特性沿流道的压力、速度场等流动特性。结果表明:微通道复杂结构会显著影响气液多相流的流动形态,复杂结构微通道加剧了流体剪切流动特性,大大促进了气液两相流混合效果。     

基于AMESim的半主动式升沉补偿系统仿真研究

为进一步研究半主动式升沉补偿的补偿工作机制,在对半主动式升沉补偿装置补偿原理分析的基础上,对装置中的气液储能器和主动补偿缸进行了力学分析和流量连续性分析,并基于AMESim软件对补偿系统进行建模和仿真分析。结果表明:补偿过程中大钩位移随时间变化范围较小,处于小幅值正弦波动范围内,系统能耗曲线近似呈线性上升趋势以及气液储能器压力曲线变化整体趋于平稳。该系统仿真结果能为半主动式升沉补偿装置的设计改进和技术发展提供参考,进一步提高系统的补偿效率和降低能耗。     

基于振动铸造的铸件结构参数优化

为了进一步改善振动铸造工况下的铸件结构,应用动网格技术与两相流模型进行复杂型腔内气液两相流的数值模拟,定位型腔内充型不完全的部位,根据实际结构进行改进,改善其充型性能。并以制动器支架铸件为例进行分析,发现制动器安装孔附近有充型不完全的现象,经过添加圆角结构,充型性能得到改善。进一步分析了分散体式结构(搅拌轮),对边角进行优化设计,获得良好的充型结构。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.