2014-07-292010-07-222010-04-09LIMA, Lidiane dos Santos Monteiro. Riemann Problems for a Symmetrical System of Two Conservation Laws. 2010. 61 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de Goiás, Goiânia, 2010.http://repositorio.bc.ufg.br/tede/handle/tde/1972In this dissertation we describe the solutions to the Riemann problem for a system of two conservation laws written in the normal from according to classification of Schaeffer-Shearer in [9]. Through changes of variables Schaeffer-Shearer determined the normal form for a nonlinear system of two conservation laws with an isolated umbilical point in state space. The normal form consists of a system of two equations, with homogeneous and quadratic functions of flow that depend only on two parameters. Also in [9] were established four distinct regions in terms of parameters, denoted by I, II, III and IV, in which varying pair of parameters in each region, the curves of waves that make up the solution of the Riemann problem have the same configuration. In this dissertation we consider the case in which the pair of parameters belongs to region IV, and in the particular case in which one of the parameters is null. In this case, the classic Lax criterion for admissibility of shocks (discontinuity solutions) generally is sufficient to obtain uniqueness of solution. Although, for some initial states, it is necessary to admit in solution also the called compressive shocks, which do not satisfy the Lax criterion.application/pdfAcesso AbertoLeis de conservaçãoproblemas de Riemannsistemas hiperbólicosConservation lawsRiemann problemshyperbolic systemsCNPQ::CIENCIAS EXATAS E DA TERRA::MATEMATICA::ANALISEDissertação