Nonlinear effects of FCI electrical conductivity on the MHD flow in DCLL blanket
Nonlinear effects of FCI electrical conductivity on the MHD flow in DCLL blanket
复制标题
DOI：
10.1016/j.fusengdes.2020.111621
复制
发表时间：
2020-08
影响因子：
1.7
通讯作者：
Long Chen;Le Hao;M. Ni;Nian-Mei Zhang
中科院分区：
文献类型：
--
作者：
Long Chen;Le Hao;M. Ni;Nian-Mei Zhang
在双冷却剂铅锂（DCLL）包层中，引入低导电性和低导热性的流道插入件（FCI），以减小MHD压降，提高传热效率。在本工作中，我们旨在通过CFD和有限元法（FEM）耦合计算平台，直接模拟具有不同电导率的典型极向导管中FCI的磁-热-流-结构多物理场，研究FCI的压力场、速度场、温度场以及变形和应力。采用一致保守格式和非结构配位网格上的PISO方法求解含洛伦兹力的不可压缩Navier-Stokes方程。结果表明：随着FCI电导率（σFCI）的增大，减压效率逐渐降低；FCI内部斑块与外部斑块的压差先减小后增大；两侧间隙出现两个射流，FCI附近的射流发展为逆流；FCI间温差和第一壁界面温度（FW）的变化是非单调的；热变形和应力随电导率非线性变化的原因是洛伦兹力对液态金属速度的非线性影响。本工作是毛毯设计的理论基础。
In a Dual Coolant Lead Lithium (DCLL) blanket, flow channel insert (FCI) with low electrical conductivity and low thermal conductivity is introduced to reduce the MHD pressure drop and improve the heat transfer efficiency. In the present work, we aim at performing a direct simulation of the magneto-thermal-fluid-structure multi-physical fields in a typical poloidal duct with different electrical conductivities of FCI, using a coupled computing platform including CFD and the finite element method (FEM), to study the pressure field, velocity field, temperature field, as well as the deformation and stresses of FCI. A consistent and conservative scheme and PISO method on an unstructured collocated mesh are employed to solve the incompressible Navier–Stokes equations with the Lorentz force included. The results show that: with the increasing of FCI's electrical conductivity (σFCI), the pressure reduction efficiency becomes lower; the pressure difference between the FCI's inside patches and the corresponding outside patches increases after an initial reducing; two jets appear in the side gap and the one near FCI develops to a reverse flow; the variation of the temperature difference across FCI and the interface temperature of first wall (FW) is non-monotonic; the cause of nonlinear variation of thermal deformations and stresses of FCI with electrical conductivity results from the nonlinear effect of Lorentz force on the liquid metal velocity. This work is the theoretical basis of blanket design.