Search results for "free boundary problems"

showing 5 items of 5 documents

Existence of viscosity solutions to two-phase problems for fully nonlinear equations with distributed sources

2018

In this paper we construct a viscosity solution of a two-phase free boundary problem for a class of fully nonlinear equation with distributed sources, via an adaptation of the Perron method. Our results extend those in [Caffarelli, 1988], [Wang, 2003] for the homogeneous case, and of [De Silva, Ferrari, Salsa, 2015] for divergence form operators with right hand side.

Class (set theory)lcsh:T57-57.97Applied MathematicsPhase (waves)Perron methodfully nonlinear elliptic equationsPerron method| two-phase free boundary problems| fully nonlinear elliptic equationstwo-phase free boundary problemsNonlinear systemSettore MAT/05 - Analisi MatematicaViscosity (programming)lcsh:Applied mathematics. Quantitative methodsFree boundary problemApplied mathematicsViscosity solutionDivergence (statistics)Perron methodMathematical PhysicsAnalysisMathematicsMathematics in Engineering
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A free boundary problem stemmed from combustion theory. Part II: Stability, instability and bifurcation results

2002

AbstractWe deal with a free boundary problem, depending on a real parameter λ, in a infinite strip in R2, providing stability, instability and bifurcation.

Partial differential equationApplied MathematicsMathematical analysisLinearizationSaddle-node bifurcationFully nonlinear elliptic and parabolic systemsBifurcation diagramFree boundary problemsInstabilityTranscritical bifurcationLinearizationFree boundary problemBifurcationStabilityBifurcationAnalysisMathematicsJournal of Mathematical Analysis and Applications
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Thin obstacle problem : Estimates of the distance to the exact solution

2018

We consider elliptic variational inequalities generated by obstacle type problems with thin obstacles. For this class of problems, we deduce estimates of the distance (measured in terms of the natural energy norm) between the exact solution and any function that satisfies the boundary condition and is admissible with respect to the obstacle condition (i.e., they are valid for any approximation regardless of the method by which it was found). Computation of the estimates does not require knowledge of the exact solution and uses only the problem data and an approximation. The estimates provide guaranteed upper bounds of the error (error majorants) and vanish if and only if the approximation c…

Applied MathematicsComputation010102 general mathematicsMathematical analysista111estimates of the distance to the exact solutionthin obstaclevariaatiolaskentaFunction (mathematics)variationals problems01 natural sciences010101 applied mathematicsExact solutions in general relativityObstacleNorm (mathematics)free boundary problemsVariational inequalityObstacle problemBoundary value problem0101 mathematicsMathematicsInterfaces and Free Boundaries
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A two-phase problem with Robin conditions on the free boundary

2020

We study for the first time a two-phase free boundary problem in which the solution satisfies a Robin boundary condition. We consider the case in which the solution is continuous across the free boundary and we prove an existence and a regularity result for minimizers of the associated variational problem. Finally, in the appendix, we give an example of a class of Steiner symmetric minimizers. peerReviewed

Class (set theory)General MathematicsBoundary (topology)variaatiolaskentaRobin boundary conditionsPhase problemRobin boundary condition01 natural sciencesFree boundary problemsRegularityMathematics - Analysis of PDEsFOS: MathematicsFree boundary problemApplied mathematics0101 mathematicsMathematicsosittaisdifferentiaaliyhtälöt010102 general mathematicsFree boundary problemFree boundary problems; Regularity; Robin boundary conditions; Two-phasematemaattinen optimointi16. Peace & justiceRobin boundary condition010101 applied mathematicsTwo-phaseAnalysis of PDEs (math.AP)
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Drops moving in flow with chernical reaction

1994

We propose a free boundary model described by coupled Navier-Stokes and chemical reaction equations with discontinuous coefRcients to simulate the chemical re- ¿ctions in viscous drops moving in a viscous incompressible ûuid. Approximation of the solution by a special ñnite element method (FEM) with a method of mapping is discussed. Several numerical resulùs åre presented.

Physics::Fluid Dynamicsfree boundary problemsfinite element methodNavier-Stokeschemical reactions
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