LI Zhengdong
,
ZHANG Guoqing
,
LI Zhou
,
ZHANG Yong
,
XU Wenyong
钢铁研究学报(英文版)
Gas flow field in nozzles and out of nozzles was calculated for Laval orifice and straight orifice nozzles. The results showed that the flow generated by the Laval nozzle had a higher exit velocity in the vicinity of the nozzle, in comparison with that of the straight nozzle, that is to say, a Laval nozzle was more efficient than a straight one in disintegrating the melt stream and was apt to produce finer powders. The flow generated by the Laval nozzle was less convergent and the velocity gradient along the radial direction was more moderate than that of a straight nozzle, which could contribute to a broad distribution of melt particles. According to their flow characteristics, the Laval nozzle was reckoned as a better choice of producing larger sprayformed billets.
关键词:
numerical simulation;computational fluid dynamics;gas flow field;atomization nozzle
F.T.Cheng
材料科学技术（英文）
The present communication addresses an interesting problem related to the indeterminacy in hardness of superelastic NiTi reported by Xu et al. The origin of the indeterminacy is attributed to the inadequacy of the conventional Vickers hardness testing measurement which does not record elastic deformation, and thus the indeterminacy may be removed with suitable techniques. Concepts of hardness in relation to deformation are clarified. Recommendations for measuring the hardness of NiTi and other elastic-plastic materials are suggested, together with comments on the advantages and disadvantages of each of these methods.
关键词:
Hardness
,
null
,
null
,
null
,
null
,
null
Jingpei XIE
,
Yaomin ZHU
,
Xiaoping WANG
材料科学技术（英文）
The M-s temperature, Delta G(gamma-->alpha), Delta G(gamma-->M) and mechanical energy under a non-severe impact loading in a medium manganese steel (Fe-7Mn-1.2C) have been calculated by means of Xu's Fe-X-C model. The relation between the yield strength of austenite and the driving force for martensite transformation has been established. It is proved that the martensite transformation can take place in a medium manganese steel (Fe-7Mn-1.2C alloy) under a non-severe impact loading.
关键词:
李莉
,
李庆芬
,
郑磊
,
徐庭栋
,
杜善义
钢铁研究学报
以工业用12Cr1MoV钢为研究对象,通过俄歇电子能谱分析方法(AES),对磷在恒温过程中的非平衡晶界偏聚浓度进行了测定.获得的磷在钢中的非平衡晶界偏聚动力学曲线直接验证了非平衡晶界偏聚动力学理论中的Xu-Song模型.
关键词:
晶界偏聚
,
临界时间
,
扩散
,
钢
陆樟献
,
龚雁
,
王渊明
,
王正才
,
陈善飞
功能材料与器件学报
doi:10.3969/j.issn.1007-4252.2012.01.005
基于Xu等人的经典振荡磁偶极子模型和Matsumoto等人给出的双折射驰豫理论,研究了磁致双折射和二向色性对磁性液体薄片的光透射率弛豫特性的影响.理论推导了磁性液体的双折射和二向色性函数的偏振光透射率具体表达式,并进行了数值模拟计算.该问题的研究对磁性液体光学各向异性的深入认识以及相关磁性液体光学器件的应用具有一定的指导意义.
关键词:
物理光学
,
双折射驰豫
,
二向色性驰豫
,
磁性液体
,
磁偶极子
周晓宏
,
刘红军
,
刘鹏
功能材料
优化技术是一种以数学为基础,可用来求解各种工程问题最优解的应用技术.本文利用磁流变阻尼器动态特性数据,采用遗传算法进行阻尼器模型参数识别优化过程,最终将得到的磁流变阻尼器模型参数用于土木工程结构振动控制研究.已建立的磁流变阻尼器的动力特性将在不同的电场强度和变化的位移幅度下进行测试,可以得到在不同位移和速度下恢复力的滞回曲线,建立Bouc-Wen模型.把根据试验得到的滞回曲线和使用遗传算法对模型参数进行优化的结果进行比较可知,这种模型的参数可以以十分小的误差得到优化.
关键词:
遗传算法
,
阻尼器
,
参数识别
吕友军
,
董旭斌
,
张天宁
工程热物理学报
本文采用基于颗粒动力学的欧拉双流体模型,对比研究了曳力和湍流对超临界水流化床传热特性的影响,选取了Gidaspow、Syamlal-O'Brien和Wen-Yu三种曳力模型以及标准κ-ε、RNG κ-ε、Realizable κ-ε湍流模型三种高Re数湍流模型及低Re数κ-ε湍流模型.研究结果表明,在三种曳力模型中,Gidaspow曳力模型在超临界水流化床中更为适用;对于所采用的四种κ-ε湍流模型,利用三种高雷诺数湍流模型模拟所得床层与壁面间传热系数基本一致且大于采用低雷诺数模型模拟所得传热系数,而综合考虑,RNGκ-s湍流模型更适于超临水流化床传热特性的研究.
关键词:
超临界水流化床
,
曳力
,
湍流
,
传热
朱奎松
,
刘松利
,
芶淑云
,
王梁
钢铁钒钛
doi:10.7513/j.issn.1004-7638.2017.02.005
基于欧拉-双流体模型和流态化氯化临界流化速度经验公式,结合云南高钛渣物性参数,研究了其流态化氯化的初始流化速度下高钛渣流态化氯化特性、气泡运动对床层的扰动、气泡大小与分布板位置关系.研究结果表明:Grace方程能准确预测B类颗粒窄粒径的高钛渣流态化氯化气泡行为,Wen-Yu方程预测的初始流化速度下乳相和气泡出现时间延后;完全流化速度下,通过上升、合并长大、破裂过程,在分布板位置形成气泡;通过钛渣固体矢量图得出,整个床层以气泡为分界,气泡上升对上、下部颗粒的流动产生影响,导致床层不均匀.
关键词:
四氯化钛
,
高钛渣
,
氯化
,
流化床
,
数值模拟
,
流动特性
