Phenomena-Based Modeling Methodology Research And Application

Advanced energy systems are the complex systems involved in a variety of physical and chemical processes, spatial-time multi-scale and complexity of all in which are a common phenomenon in nature and are difficult to quantify. Currently, the average expression commonly used to depict the macroscopical phenomenon does not reveal the inherent mechanism of the process, which makes it difficult to accurately predict. The fundamental solution of this problem lies in micro-mechanism simulation. In recent years been concerned about multi-scale analysis, which is to seize those important features and simplify analysis and the process has not yet penetrated into all the internal mechanism, but it is a very effective way. To consider multi-scale effects, multi-scale modeling of a complex system based on the time and spatial characteristics of the multi-scale, involves different simulation methods and means in each scale simulation. The complex systems using multi-scale simulation will not only reveal the essence of the phenomenon, but also make the design and quantify of complex systems realizable. Therefore, multi-scale simulation modeling method has an important theoretical and practical value in the advanced energy systems.This thesis includes two parts of research work: the first part studies the phenomenon-based modeling method for implementing the multi-scale modeling and the different model of the coupling mechanism. The second part takes solid oxide fuel cell (SOFC) as an example for multi-scale simulation and verification modeling method based on the phenomenon, which contains the following two aspects:1. Lattice Boltzmann method is used to model electrochemical reaction-diffusion and study gas concentration and the current density distribution in the electrochemical reaction;2. The steady-state model of the tubular SOFC is computed. A CFD model coupled with reaction diffusion meso-scale model for a tubular SOFC bases on mass, momentum and energy balance coupled with fluid flow, heat generation and transfer and electrochemistry. The model describes the fluid flow, heat and mass transfer in the SOFC, and also investigates the profile of temperature, gas flow rate in the SOFC.This paper establishes a modeling method based on the phenomenon of the framework initially and realizes the macroscopical model and mesoscopical model of co-simulation effectively. The simulation results show that the complex energy systems of multi-scale simulation based phenomenon of modeling method is an effective method.