A FRACTAL MODEL OF PERMEABILITY FOR THE LIQUID HELIUM FLOW IN CABLE-IN-CONDUIT CONDUCTORS
A FRACTAL MODEL OF PERMEABILITY FOR THE LIQUID HELIUM FLOW IN CABLE-IN-CONDUIT CONDUCTORS
复制标题
电缆导管中液氦流动渗透率的分形模型
DOI：
10.1142/s0218348x19500646
复制
发表时间：
2019-07
影响因子：
4.7
通讯作者：
Gao Yuanwen
中科院分区：
文献类型：
--
作者：
Ma Zhicai;Ta Wurui;Gao Yuanwen
管道内电缆导体的散热性能和冷却剂泵送成本取决于液氦流的热水力学特性。因此，准确的流体热水力学知识对电缆的设计，特别是对渗透率的设计具有重要意义。本文提出用分形方法来描述索截面，并推导出近似表达式。在此基础上，基于多孔介质类比，提出了氦在ccic中流动的分形渗透率模型。通过预测值与实验值的比较，验证了该模型的可行性和有效性。分形模型表明，电缆的渗透率由电缆的几何参数决定，如有效孔隙率、平均布线角度、平均股径和电缆截面孔隙面积分形维数。该模型不包含任何经验常数和拟合常数，可用于解释机理和预测氦在ccic中的渗透率。此外，还分析和模拟了锚索几何特性对所建立的分形渗透率模型的影响。结果表明：电缆的渗透率随电缆夹角的增大而减小，随有效孔隙率的增大而增大，孔隙分形维数和平均直径增大；这些结果与实际情况一致。
The heat removal capability and the coolant pumping costs in the design of cable-in-conduit conductors are depend on the thermo-hydraulics of the liquid helium flow. Therefore, the accurate knowledge of the thermo-hydraulics of the flow is significant for the design of the cables, especially for permeability. In this paper, the fractal method is proposed to describe the cable cross-section and an approximate expression is derived. Then, a fractal permeability model for helium flow in CICCs is presented based on a porous medium analogy. The feasibility and validity of this model is verified by the comparison of the predicted values and the experimental values. The fractal model indicates that permeability of cables is determined by the cable geometric parameters, such as the effective porosity, the average cabling angle, the average diameter of strands and the pore area fractal dimension of the cable cross-section. This model does not contain any empirical constants or fitting constants and can be used to explain the mechanism and to predict the permeability of the helium flow in CICCs. Furthermore, the effects of cable geometric characteristics on the presented fractal permeability model are also analyzed and simulated. The results imply that permeability of cables decreases with increasing the cabling angle, increases with the effective porosity, the pore fractal dimension and the average diameter of the strands increase. These results are consistent with the physical situations.
登录
查看更多内容
影响因子：
5.2
作者：
B. Ramakrishnan;R. Pitchumani
通讯作者：
B. Ramakrishnan;R. Pitchumani
影响因子：
2.1
作者：
M. Hoenig;D. Montgomery
通讯作者：
M. Hoenig;D. Montgomery
DOI：
10.1016/j.ijheatmasstransfer.2009.01.024
发表时间：
2009-06
影响因子：
5.2
作者：
Meijuan Yun;Bo-ming Yu;Jianchao Cai
通讯作者：
Meijuan Yun;Bo-ming Yu;Jianchao Cai
影响因子：
1.8
作者：
Mitchell, N.;Bessette, D.;Simon, F.
通讯作者：
Simon, F.
DOI：
10.1016/s0017-9310(02)00014-5
发表时间：
2002-07-01
影响因子：
5.2
作者：
Yu, BM;Cheng, P
通讯作者：
Cheng, P