2022 Fiscal Year Final Research Report
Turbulent Supernovae Explosion
| Project/Area Number |
18H01212
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Review Section |
Basic Section 15010:Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics
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| Research Institution | The University of Tokyo |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
政田 洋平 愛知教育大学, 教育学部, 准教授 (30590608)
滝脇 知也 国立天文台, 科学研究部, 助教 (50507837)
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| Project Period (FY) |
2018-04-01 – 2022-03-31
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| Keywords | 超新星爆発 / 乱流 / 対流 / プリューム / 非平衡効果 / 時間ー空間二重平均 / エネルギー交換 / 速度シア |
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| Outline of Final Research Achievements |
In order to construct a self-consistent turbulence model for supernovae explosion, we incorporate the non-equilibrium turbulence for the stellar convection in the framework of the time-space double averaging procedure. The diving plumes radiatively cooled at the stellar surface cause a strong mass and heat mixing in the stellar convection zone. This turbulent transport cannot be reproduced by the usual gradient-diffusion model with mixing-length theory. With the aid of the non-equilibrium effect along the plume motions, this strongly localised enhanced turbulent mixing was for the first time successfully reproduced by the present turbulence model. In addition, the energy transfer between the coherent fluctuations (plumes) and the incoherent fluctuations (random noises) are scrutinised through the evolution equations of the coherent and incoherent turbulent energies. It was shown that the shear of the plume motion is essential.
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| Free Research Field |
非一様乱流の理論解析とそれに基づく乱流モデリング
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| Academic Significance and Societal Importance of the Research Achievements |
近年，超新星爆発の研究は大規模数値シミュレーションを用いて大きな発展を遂げつつあるが，内部の乱流現象の理論的解明にはほど遠い．一方，従来の乱流モデルは，混合距離理論に代表されるように，経験的にその場限りで与えられるものにとどまっている．本研究では，基礎方程式に基づいた乱流モデルを構築した．二重平均の枠組みで，乱れのコヒーレント成分（プリューム）とインコ ヒーレント成分（ランダム乱れ）との間のエネルギー交換を特定し，プリュームの速度勾配とランダム乱れ応力の結合が，恒星表面での冷却と 恒星内部でのエネルギー散逸とを繋ぐ鍵となることを初めて示した．
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