Multiphase Saturation Equations, Change of Type and Inaccessible Regions
We identify a class of flux functions which give rise to conservation laws which are hyperbolic except along a codimension one subspace of state space. We show that a number of systems modelling porous medium flow can be regarded as perturbations of such systems, and describe the phenomenon of change of type for these perturbations. We also discuss a property of solutions of such systems, the existence of inaccessible regions - subsets of state space which appear to be avoided by solutions.
KeywordsHyperbolic System Riemann Problem Flux Function Polymer Flooding Riemann Solution
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