THE SCALE DECOUPLING APPROACHES IN MODELING OF COMPLEX FLUID PROCESSES
The multi-scale physics is originated from the emergence idea, a layered view of nature. Emergent entities arise out of more fundamental entities and yet are novel or irreducible with respect to them. While the existence of ontological emergence is still controversial among philosophers, physicists already started to analyze the emergent behaviors of complex systems including complex fluids. The coupling and decoupling between the layers are essential for the multi-scale modeling. A simple, yet classic example is the polymer dynamics of solutions and melts. As the molecular weight grows up to a minimum Gaussian coil -the segment, a higher layer emerges. A self similar fractal chain can be modeled as bead-spring chain showing relaxation time spectrum and dynamic scaling law. As the concentration increasing, the minimum Gaussian segments feel constrained except diffusing along the chain contour, the tube entangled network thus formed with the tube diameter closing to segment dimension of nanometers. Thus, for the theory to correlate the chemical structure with macroscopic rheological properties, the segment/tube scale is critical to couple the layers up/down and also to decouple the scales allowing the model irrelevant to the lower scale, leaving all the chemical structural details in model parameters. In this paper we use this approach to analyze systems with more complexity of gelation and multi-phase fluids. They all relate to practical polymer processes.
Yuanze Xu
College of Chemistry & Chemical Eng.,Xiamen University, 361005, Xiamen, China Dept.Macromolecular Science, Fudan University, Shanghai, 200433, China
国际会议
PP’2010，Jinan International Symposium on Polymer Physics(2010济南国际高分子物理学术研讨会)
济南
英文
98-99
2010-06-06（万方平台首次上网日期，不代表论文的发表时间）