دورية أكاديمية

ENTROPY-PRESERVING COUPLING CONDITIONS FOR ONE-DIMENSIONAL EULER SYSTEMS AT JUNCTIONS.

التفاصيل البيبلوغرافية
العنوان: ENTROPY-PRESERVING COUPLING CONDITIONS FOR ONE-DIMENSIONAL EULER SYSTEMS AT JUNCTIONS.
المؤلفون: Lang, Jens, Mindt, Pascal
المصدر: Networks & Heterogeneous Media; 2018, Vol. 13 Issue 1, p177-190, 14p, 2 Graphs
مصطلحات موضوعية: PIPE flow, RIEMANN-Hilbert problems, CONSERVATION of mass, DYNAMIC pressure, CAUCHY problem, ISOTHERMAL processes
مصطلحات جغرافية: THAILAND
مستخلص: This paper is concerned with a set of novel coupling conditions for the 3× 3 one-dimensional Euler system with source terms at a junction of pipes with possibly different cross-sectional areas. Beside conservation of mass, we require the equality of the total enthalpy at the junction and that the specific entropy for pipes with outgoing flow equals the convex combination of all entropies that belong to pipes with incoming flow. Previously used coupling conditions include equality of pressure or dynamic pressure. They are restricted to the special case of a junction having only one pipe with outgoing flow direction. Recently, Reigstad [SIAM J. Appl. Math., 75:679-702,2015] showed that such pressure-based coupling conditions can produce non-physical solutions for isothermal flows through the production of mechanical energy. Our new coupling conditions ensure energy as well as entropy conservation and also apply to junctions connecting an arbitrary number of pipes with flexible flow directions. We prove the existence and uniqueness of solutions to the generalised Riemann problem at a junction in the neighbourhood of constant stationary states which belong to the subsonic region. This provides the basis for the well-posedness of the homogeneous and inhomogeneous Cauchy problems for initial data with sufficiently small total variation. [ABSTRACT FROM AUTHOR]
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قاعدة البيانات: Complementary Index
الوصف
تدمد:15561801
DOI:10.3934/nhm.2018008