Search results for " Spectral methods"

showing 4 items of 4 documents

Singularity formation and separation phenomena in boundary layer theory

2009

In this paper we review some results concerning the behaviour of the incompressible Navier–Stokes solutions in the zero viscosity limit. Most of the emphasis is put on the phenomena occurring in the boundary layer created when the no-slip condition is imposed. Numerical simulations are used to explore the limits of the theory. We also consider the case of 2D vortex layers, i.e. flows with internal layers in the form of a rapid variation, across a curve, of the tangential velocity.

Prandtl's equations Separation Spectral Methods Complex singularities Blow up time Regularizing viscosityBoundary layerClassical mechanicsSingularityDynamical systems theoryGeometric mechanicsDifferential equationComputational mechanicsFluid mechanicsSettore MAT/07 - Fisica MatematicaBoundary element methodMathematicsMathematical physics
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Singularities for Prandtl's equations.

2006

We used a mixed spectral/finite-difference numerical method to investigate the possibility of a finite time blow-up of the solutions of Prandtl's equations for the case of the impulsively started cylinder. Our toll is the complex singularity tracking method. We show that a cubic root singularity seems to develop, in a time that can be made arbitrarily short, from a class of data uniformely bounded in H^1.

Prandtl’s equations Separation Spectral methods Complex singularities Blow–up time Regularizing viscosity.Settore MAT/07 - Fisica Matematica
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Mauro Picone, Sandro Faedo, and the numerical solution of partial differential equations in Italy (1928-1953)

2013

In this paper we revisit the pioneering work on the numerical analysis of partial differential equations (PDEs) by two Italian mathematicians, Mauro Picone (1885-1977) and Sandro Faedo (1913-2001). We argue that while the development of constructive methods for the solution of PDEs was central to Picone's vision of applied mathematics, his own work in this area had relatively little direct influence on the emerging field of modern numerical analysis. We contrast this with Picone's influence through his students and collaborators, in particular on the work of Faedo which, while not the result of immediate applied concerns, turned out to be of lasting importance for the numerical analysis of …

Partial differential equationNumerical analysisApplied MathematicsConstructiveSettore MAT/08 - Analisi NumericaIstituto per le Applicazioni del CalcoloHistory of numerical analysi Istituto per le Applicazioni del Calcolo Evolution problems Faedo–Galerkin method Spectral methodsHistory of numerical analysiCalculusApplied mathematicsEvolution problemFaedo-Galerkin methodAlgebra over a fieldSpectral methodSturm–Picone comparison theoremSpectral methodNumerical partial differential equationsMathematics
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Multi-domain spectral approach with Sommerfeld condition for the Maxwell equations

2021

We present a multidomain spectral approach with an exterior compactified domain for the Maxwell equations for monochromatic fields. The Sommerfeld radiation condition is imposed exactly at infinity being a finite point on the numerical grid. As an example, axisymmetric situations in spherical and prolate spheroidal coordinates are discussed.

Physics and Astronomy (miscellaneous)Helmholtz equationRotational symmetryMaxwell equationsHelmholtz equationsSommerfeld conditionMulti domain spectral methodsSpheroidal coordinates010103 numerical & computational mathematicsSommerfeld radiation condition01 natural sciencesDomain (mathematical analysis)010305 fluids & plasmassymbols.namesake0103 physical sciencesFOS: Mathematics[INFO]Computer Science [cs]Mathematics - Numerical Analysis0101 mathematics[MATH]Mathematics [math]Physics[PHYS]Physics [physics]Numerical AnalysisApplied MathematicsMathematical analysisNumerical Analysis (math.NA)Prolate spheroidal coordinatesComputer Science ApplicationsComputational MathematicsDipoleMaxwell's equationsModeling and SimulationsymbolsMonochromatic color
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