## The Riemann problem for multicomponent polymer flooding.(English)Zbl 0686.35077

The paper considers the construction of global solutions of the Riemann problem for the nonstrictly hyperbolic system of conservation laws $s_ t+f(s,c_ 1,...,c_ n)=0;\quad [sc_ i+a_ i(c_ i)]_ t+[c_ if(s,c_ 1,...,c_ n)]_ x=0,\quad i=1,2,...,n,$ where $$(s,c_ 1,...,c_ n)\in [0,1]^{n+1}$$; $$f(\cdot,c_ 1,...,c_ n)$$ is increasing, with an inflection point, $$f(s,c_ 1,...,c_{i- 1},\cdot,c_{i+1},...,c_ n)$$ is decreasing for all i, $$a_ i(\cdot)$$ is of Langmuir type, i.e. is concave, increasing and $$a_ i(0)=0.$$
First elementary waves are determined: rarefaction waves, i.e. smooth solutions and shock waves. The general solution is obtained by composing waves and constant states.
Reviewer: V.Rasvan

### MSC:

 35L65 Hyperbolic conservation laws 76S05 Flows in porous media; filtration; seepage 35L67 Shocks and singularities for hyperbolic equations
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