FE/MCT: Macroscopic CFD Simulations of Glass-Forming Fluids using Material Laws from Microscopic Theory

我们开发了一个多尺度的描述玻璃形成流体的流动。为此，我们结合联合收割机计算流体动力学（CFD）模拟与微观理论，提供材料的法律（本构方程）的非线性响应的强粘弹性流体。通过瞬态（ITT）的积分形式主义是用来推导广义格林-久保关系，链接微观相关函数的粗粒流体应力张量远离平衡。模式耦合理论的玻璃化转变（MCT）一起使用ITT提供一个微观合理的封闭的材料模型。由此产生的本构方程的特点是明显的时程积分。高级有限元法（FEM）计划的实现，以处理这样的积分本构方程的水平上的Navier-Stokes方程，能够解决显着的瞬态和记忆效应的玻璃形成流体的流动。使用这些工具，我们解决了玻璃在施加载荷下的缓慢变形，以及当材料在不同的加工条件下制备时，非晶软物质材料的历史相关材料特性的出现。

We develop a multi-scale description of the flow of glass-forming fluids. To this end we combine computational fluid dynamics (CFD) simulations with microscopic theory to provide material laws (constitutive equations) of the nonlinear response of the strongly viscoelastic fluid. The integration-through transients (ITT) formalism is used to derive generalized Green-Kubo relations that link microscopic correlation functions to the coarse-grained fluid stress tensor far from equilibrium. The mode-coupling theory of the glass transition (MCT) is used together with ITT to provide a microscopically justified closed material model. The resulting constitutive equations are characterized by pronounced time-history integrals. Advanced Finite Element method (FEM) schemes are realized in order to deal with such integral constitutive equations on the level of the Navier-Stokes equations, to be able to address the pronounced transients and memory effects in the flow of glass-forming fluids. Using these tools, we address the slow deformation of glasses under applied load and the emergence of history-dependent material properties of amorphous soft-matter materials that arise when the material is prepared under different processing conditions.