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We have introduced new shock capturing schemes that reduce the numerical
diusion at discontinuities, sharpen the discontinuities in derivative and
avoid spurious oscillations, improving the behavior of essentially non oscillatory
schemes and piecewise hyperbolic methods. We have introduced and analyzed in
this work a new class of limiter functions, the so called power limiters", which
are an essential tool for the construction of these schemes.
When power limiters are used as limiters of rst or second order dierences,
the resulting methods behave essentially non-oscillatory near discontinuities and
they allow simple expressions of the local truncation errors when they are used
as limiters of second order dierences.
We have used the powereno limiter as a slope limiter for the design of a new
piecewise hyperbolic method called the Power PHM method. The third order
accurate Power PHM scheme improves the behavior of PHM at local extrema and
contact discontinuities, and it shares the advantages of the PHM. Since these are
compact schemes (three point stencil), Power PHM is recommended over PHM
when this condition is convenient for the computation (e.g., relaxation schemes).
We have also used the powereno limiter applied to consecutive second order
nite dierences to construct the Power ENO method. We have analyzed a new
fth order accurate Weighted Power ENO method as a nonlinear convex combination
of the three Power ENO parabolas. Our fth order accurate Weighted
PowerENO scheme improves the behavior of WENO5 reducing the numerical
viscosity at contact discontinuities and local extrema. It captures ner scales for
a xed computational grid. Our scheme is recommended when high order accuracy
is a goal and when dealing with numerical schemes and simulations where a
reduced (compact) stencil is not necessary.
We have checked the robustness, stability and accuracy of the proposed schemes
in a set of model problems by means of several numerical tests, including the shock
entropy wave interaction, two interacting blast waves, the two dimensional four
contacts Riemann problem and the two dimensional four shocks problem. Finally,
we have shown the ability of the presented schemes in resolving ne scales
near unstable interfaces by computing Rayleigh-Taylor and Richtmyer-Meshkov
instabilities.
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RESUMEN
Hemos introducido nuevos metodos de captura de ondas de choque que reducen
la difusion numerica en las discontinuidades, denen ntidamente las discontinuidades
en derivada y evitan las oscilaciones espureas, mejorando el comportamiento
de los esquemas esencialmente no oscilatorios y los metodos hiperbolicos
a trozos. Hemos introducido y analizado en este trabajo una nueva clase
de funciones limitadoras, los llamados power limiters" que son una herramienta
esencial para la construccion de estos esquemas. Hemos utilizado el limitador
powereno" como limitador de pendiente para el dise~no de un nuevo metodo
hiperbolico a trozos que llamamos metodo Power PHM. Tambien hemos utilizado
el limitador powereno aplicado a segundas diferencias contiguas para construir el
metodo Power ENO. Hemos analizado un nuevo metodo de quinto orden de precisi
on espacial, el metodo Weighted PowerENO, como una combinacion convexa
no lineal de las tres parabolas PowerENO. Hemos comprobado la robustez, estabilidad
y precision de los esquemas propuestos para un conjunto de problemas
modelo mediante varios experimentos numericos. Finalmente hemos demostrado
la capacidad de los esquemas presentados en la resolucion de las escalas nas
en el entorno de interfases inestables mediante el calculo de inestabilidades de
Rayleigh-Taylor y Richtmyer-Meshkov.
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