2014 Fiscal Year Final Research Report
Stability of Shock Wave and Global Star Formation in Spiral Galaxies
| Project/Area Number |
24540226
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Astronomy
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| Research Institution | Chiba University |
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Principal Investigator |
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Keywords | 衝撃波 / 数値シミュレーション / 安定性 |
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| Outline of Final Research Achievements |
The researcher has examined numerical solutions of flows associated with strong shock in order to explore the origin of the wiggle instability appearing in the numerical models of spiral galaxies. The role of the bulk viscosity in particular has been investigated. The bulk viscosity dominates the pressure tensor in extremely thin shock transition layers, although it is negligibly small outside them. The shock transition layers are artificially broadened in numerical simulations owing to the finite resolution. Hence the bulk viscosity should be enhanced to evaluate the contribution to the pressure tensor appropriately. The numerical solutions obtained with the enhanced bulk viscosity shows convergence to the classical jump solution in the highest resolution limit. They are invariant under the rotation of the numerical grid and the Galilean transformation.
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| Free Research Field |
理論天文学
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