The basics of TEMOM for Brownian Coagulation

来源: 机电工程学院 作者:汪家琦 添加日期:2018-05-08 16:28:12 阅读次数: 1805

       报告题目:The basics of TEMOM for Brownian Coagulation
  报告内容:In coal combustion process, aerosol dynamics plays an important role. In 2008, Yu and Lin have proposed a moment-based approach, termed as the Taylor series expansion method of moment (TEMOM), to approximate the population balance equation which governs the coal particles in combustion flows. This approach makes no prior assumption on the shape of particle size distribution; the derivation of TEMOM is completely based on Taylor series expansion. In 2012, my collaborators and I developed a compact and fast MATLAB program coupled with TEMOM to simulate the effect of coherent structures on the particle Brownian coagulation in the temporal mixing layer (JAS, 2012). The results show that the particle coagulation within the eddy core has an obvious wave-like distribution similar to the large-scale eddy structures, which indicate that the relative growth rate is slow at long times, and the system bottleneck is the advection and diffusion.
  The self-similarity also implies that the effect of coagulation and effect of mixing by advection and diffusion on particle growth could be modeled separately. Since the TEMOM moment method was proposed in 2008, it has been widely discussed by scholars all around the world. They proposed some fundamental problems for TEMOM model, such as the uniqueness of the expansion, the effectiveness for the closuring fractional moments, the choice of the expansion point, the convergence of the analytical solutions, and the inverse problem, etc. Some problem has been clariRied taking the TEMOM model for Brownian coagulation in the free molecule regime as an example (HMT, 2014). And most of the fundamental problems can be attributed to the error analysis of TEMOM model; based on the lognormal size distribution assumption, the system errors are obtained for different TEMOM models due to Brownian coagulation (AST, 2016).