隋艳伟
,
李邦盛
,
刘爱辉
,
熊艳才
,
郭景杰
,
傅恒志
材料研究学报
对离心力场作用下液态金属充型流动过程中气体的溶解度、气泡的形核条件、形核功、临界形核半径以及形核率进行了定量研究. 结果表明,在离心力场作用下气体的溶解度是一个梯度量, 随着离心半径和离心角速度的增大而增大;气泡的形核功和临界形核半径也随着离心半径和离心角速度的增大而增大,而气泡的形核率相应地减小; 离心半径和离心角速度越大,对气体溶解度和气泡形核的影响越明显;因此, 在离心力场作用下可通过提高离心旋转角速度和离心半径减少气孔缺陷.
关键词:
金属材料
,
centrifugal casting
,
theoretical analysis
,
gas bubble
,
nucleation
$ D.L*
,
D.N.He
,
X.J.Bao
,
Y. Q.Zhang
,
X. Y.Ruan
,
J.L. Cheng and J. Y. Jiang 1) National Die & Mold CAD Engineering Research Center
,
Shanghai Jiaotong University
,
Shanghai 200030
,
China 2) Shanghai Volkswagen Automotive Company Limited
,
Shanghai 201805
,
China
金属学报(英文版)
With the combination of a new theoretical formula, physical simulation experiments, the technology of artificial neural network and database, an intelligent system for the prediction of sheet metal drawing capability is constructed for the first time. A modified criterion for sheet metal drawing capability is proposed in this paper, namely, the Technological Limiting Drawing Ratio, TLDR = f(R, n, s, t, F, μ,r_d,r_p…). Based on the studies of other scholars, a new formula is derived to predict the TLDR in this paper. Then a series of orthogonal physical simulation experiments are designed to investigate the effect of technological parameters on the TLDR, and the results are analyzed in the paper. Then the predicting system is constructed with the combination of the theoretical formula, orthogonal experiments, the technology of artifocial neural network and database. The predicted results show good agreements with experimental data, so it can be used to avoid the blindness in the selection of sheet metal before stamping. The system operates under the Windows operating system, and it supports the mechanism of Client/Server as well as Intranet, so the system has high engineering value.
关键词:
TLDR
,
null
,
null
,
null
,
null
,
null
,
null
李晓伟
,
杨明昆
,
宋宇
,
李笑天
,
何树延
工程热物理学报
自然循环载热系统由密度差引起的重位压差驱动,驱动压头小且受冷热源位置和冷热流体温度影响,因此摇摆等海洋工况会对自然循环载热系统的载热能力产生较大影响.在固连坐标系内,采用理论分析和数值计算方法对自然循环载热系统的流量及载热能力进行了研究.理论分析给出了摇摆产生的各项附加力对自然循环载热系统的流量及载热能力的影响机理,并得到了摇摆条件下自然循环系统流量的常微分控制方程.数值计算方法中针对动量方程添加了由于摇摆产生的各种附加作用力项.数值计算得到的系统流量波动结果与理论分析结果吻合得很好,并且数值计算还给出了由于摇摆使系统载热能力下降的幅度.
关键词:
自然循环
,
摇摆
,
理论分析
,
数值计算
,
科氏力
,
离心力
