Institut für Geophysik Geschäftsführender Direktor:
Prof. Dr. Ulrich Hansen

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Numerically determined transport laws for fingering ("thermohaline") convection in astrophysics

Adrienne Traxler, Pascale Garaud, Stephan Stellmach

 We present the first three-dimensional simulations of fingering convection performed in a parameter regime close to the one relevant for astrophysics, and reveal the existence of simple asymptotic scaling laws for turbulent heat and compositional transport. These laws can straightforwardly be extrapolated to the true astrophysical regime. Our investigation also indicates that thermocompositional "staircases," a key consequence of fingering convection in the ocean, cannot form spontaneously in the fingering regime in stellar interiors. Our proposed empirically-determined transport laws thus provide simple prescriptions for mixing by fingering convection in a variety of astrophysical situations, and should, from here on, be used preferentially over older and less accurate parameterizations. They also establish that fingering convection does not provide sufficient extra mixing to explain observed chemical abundances in RGB stars.


Astrophysical Journal, 728, L29 (2011)

 


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Institut für Geophysik Geschäftsführender Direktor:
Prof. Dr. Ulrich Hansen

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· 48149 Münster
Tel.: +49 251 83-33590 · Fax: +49 251 83-36100
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