The development of solution methods on electro-magnetic fields, sound fields and related coupled systems by means of domain decomposition method and optimization theory

本研究项目旨在开发求解方法来分析环境问题中出现的复杂现象，即人体内的液体流动。(1)川田秀夫及其合作者发展的多相流分布理论方法(DTAMF)用于分析相间边界上相互作用的多相流，该方法被有效地用于计算潮滩附近产生的流动问题，包括海滩上的空气和地球上的流动，海滩上和地球上的海水流动，以及海滩上和地球上的溢油。特别值得注意的是，利用DTAMF的结果模拟了溢油在沙滩上的细菌分解和附着现象。用DTAMF分析了液体在脊髓附近复杂结构中的流动。(2)广岛大学课题组从环境实验的角度讨论了沙质海滩或潮滩边缘的波浪对海水的作用，以确定海岸生态系统中物种的生存。我们试图通过构建一个与破碎波和生态系统动力学相联系的数学模型来解释这一实验结果，其中相场模型和遗传算法发挥了重要作用。基于这一思想，进行了数值模拟。

This research project intended to develop solution methods to analyze complex phenomena arising in environmental problems, flow of liquids in human body.(1)The Distribution Theoretic Approach to Multi-phase Flow (DTAMF) developed by Hideo Kawarada and his collaborators to analyze multi-phase flow interacting each other at the boundary between phases, which was effectively used to compute the flow problems arising in the neighborhood of tidal flats including the flows of air on the beach and in the earth, sea water on the beach and in the earth, and spilled oil on the beach and in the earth. Especially it should be noted that decomposition of spilled oil by bacteria and adhesive phenomena of oil on a sandy beach were simulated by use of the results obtained in DTAMF. DTAMF was also applied to analyze the motion of liquids to flow through complex structure near the spinal cord.(2)The role of waves at margins of sandy beach or a tidal flat to sea water for determination of species survival in a coastal ecosystem was discussed from a view point of environmental experiments by the group of Hiroshima University. We tried to interpret this experimental result by constructing a mathematical model connected with breaking waves and ecosystem dynamics, in which a phase field model and genetic algorithm played important roles. The numerical simulation was done due to this idea.