Acta mathematica scientia,Series B ›› 2009, Vol. 29 ›› Issue (6): 1613-1628.doi: 10.1016/S0252-9602(10)60005-7

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ASYMPTOTIC RAREFACTION WAVES FOR BALANCE LAWS WITH STIFF SOURCES

 W. Lambert, D. Marchesin   

  1. 1-Instituto Nacional de Matematica Pura e Aplicada, Estrada Dona Castorina 110, 22460-320 Rio de Janeiro, RJ, Brazil|Instituto de Matem\'atica Pura e Aplicada, Estrada Dona Castorina 110, 22460-320 Rio de Janeiro, RJ, Brazil
  • Received:2009-10-25 Online:2009-11-20 Published:2009-11-20
  • Supported by:

    This work was supported in part by: CNPq under grant 141573/2002-3, ANP/PRH-32, CNPq under Grant 301532/2003-6, FAPERJ
    under Grant E-26/152.163/2002, FINEP under CTPETRO Grant 21.01.0248.00, PETROBRAS under CTPETRO Grant 650.4.039.01.0, Brazil.

Abstract:

We  study the long time formation of rarefaction waves appearing in balance laws by means of singular perturbation methods. The balance laws are non standard because they contain a variable u that appears only in the flux terms.  We present a concrete example occurring in flow of steam, nitrogen and water in porous media and an abstract example for a class of systems of three equations. In the concrete example the zero-order equations resulting from  the expansion yield a type  of conservation law system called  compositional model in Petroleum Engineering. In this work we show how  compositional models originate from physically  more fundamental systems of balance laws. Under appropriate conditions, we prove that certain solutions of the system of balance laws decay with time to rarefaction wave solutions in  the compositional model originating from the system of balance laws.

Key words: balance laws, asymptotic expansion, rarefaction waves, compositional models

CLC Number: 

  • 35L65
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