2021 Fiscal Year Final Research Report
Development of Heat Transfer Model for Connected Space Using Percolation Theory
| Project/Area Number |
20K20971
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Review Section |
Medium-sized Section 19:Fluid engineering, thermal engineering, and related fields
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| Research Institution | Kyoto University |
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Principal Investigator |
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| Project Period (FY) |
2020-07-30 – 2022-03-31
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| Keywords | 伝熱 / パーコレーション理論 / 確率統計分布 / ワイブル分布 / ナノワイヤ / 連結構造体 / 2次元サーマルリフレクタンス法 |
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| Outline of Final Research Achievements |
We developed a compact thermal model based on percolation theory and stochastic process to solve the problem of heat transfer path, thermal conductivity, and heat transfer rate of a structure composed of stochastic connection which cannot always be solved by conventional continuous mechanics. We built a two-dimensional nanoscale temperature measurement system based on Thermal Reflectance Imaging method and measured the temperature distribution of nano-wire network consisting of connected structure. Comparing the results with the numerical simulation and inverse problem solution, we evaluated the electric current path, Joule heating, and heat transfer characteristics and validated the proposed model. Further, we applied the measurement technique and model to the void generation and growth in the wire meeting electromigration, and showed the possibility of analyzing the phenomena and predicting the failure time of the wire using the proposed model.
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| Free Research Field |
伝熱工学
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| Academic Significance and Societal Importance of the Research Achievements |
高度化・複雑化する機器や材料の構造は均質・一様ではなく確率連結を有する構造体である場合がある．これらの構造体の電気・伝熱特性は従来の連続体力学では表せない特性を持ち，新しい数理モデルの開発が必要となる．例えばナノワイヤを無作為に散布した構造体は，ワイヤ同士の連結と連結部の特性により通電や伝熱の経路と輸送量は従来の法則では表せないことがある．本研究では空間連結と確率論に基づく数理モデルを構築し，これらの連結を有する構造体の通電・伝熱特性に適用して実験によりモデルの妥当性を検証した．本モデルの発展は高度化する機械・材料・システムの輸送・性能評価に適用し，新しい設計と信頼性評価への貢献が期待できる．
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