• Title/Summary/Keyword: magnetohydrodynamics

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INTEGRAL ESTIMATES OF MAGNETOHYDRODYNAMICS EQUATIONS

  • Kim, Sang-Jeong
    • Journal of the Korean Mathematical Society
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    • v.35 no.4
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    • pp.869-880
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    • 1998

  • In this paper, we show that the weak solutions of the time-dependent Magnetohydrodynamics equations in 3 dimensional periodic domain belong to L(equation omitted)(0, T; V$_{r}$) following the method of Foias-Guillope-Temam for Navier-Stokes equations.s.

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Numerical Simulations for Magnetohydrodynamics based on Upwind Schemes

  • Jang, Hanbyul;Ryu, Dongsu
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.119.2-119.2
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    • 2014

  • Many astrophysical phenomena involve processes of magnetohydrodynamics (MHD) and relativistic magnetohydrodynamics (RMHD). A number of numerical schemes have been developed to solve the equations of ideal MHD and RMHD. Recent codes are based on upwind schemes which solve hyperbolic systems of equations following the characteristics of the systems. Upwind schemes stand out by their robustness, clarity of the underlying physical model, and ability of achieving high resolution. We present MHD and RMHD codes based on the total variation diminishing (TVD) and weighted essentially non-oscillatory (WENO) schemes, which are second and higher order accurate extensions of upwind schemes. We demonstrate the ability and limitation of codes based on upwind schemes through a series of tests.

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Robust technique using magnetohydrodynamics for safety improvement in sodium-cooled fast reactor

  • Lee, Jong Hui;Park, Il Seouk
    • Nuclear Engineering and Technology
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    • v.54 no.2
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    • pp.565-578
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    • 2022

  • Among Generation IV reactors, the sodium-cooled fast reactor (SFR) is attracting attention as a system having great potential for commercial use. Gas entrainment is a thermal-hydraulic issue related to the safety problem of the reactor core in the SFR. Typically, a dipped plate or baffles are installed under the free surface to suppress gas entrainment. However, these approaches can cause gas entrainment in other locations and require many trial-and-error and verifications. In this study, a new strategy using magnetohydrodynamics to suppress gas entrainment in the SFR is proposed. In a counter-flow model, a judgment criterion of gas entrainment occurrence was developed for both water and liquid metal. Moreover, the gas entrainment can be completely suppressed by applying a magnetic field.

  • https://doi.org/10.1016/j.net.2021.08.025 인용 PDF KSCI

A MULTI-DIMENSIONAL MAGNETOHYDRODYNAMIC CODE IN CYLINDRICAL GEOMETRY

  • Ryu, Dong-Su;Yun, Hong-Sik;Choe, Seung-Urn
    • Journal of The Korean Astronomical Society
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    • v.28 no.2
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    • pp.223-243
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    • 1995

  • We describe the implementation of a multi-dimensional numerical code to solve the equations for idea! magnetohydrodynamics (MHD) in cylindrical geometry. It is based on an explicit finite difference scheme on an Eulerian grid, called the Total Variation Diminishing (TVD) scheme, which is a second-order-accurate extension of the Roe-type upwind scheme. Multiple spatial dimensions are treated through a Strang-type operator splitting. Curvature and source terms are included in a way to insure the formal accuracy of the code to be second order. The constraint of a divergence-free magnetic field is enforced exactly by adding a correction, which involves solving a Poisson equation. The Fourier Analysis and Cyclic Reduction (FACR) method is employed to solve it. Results from a set of tests show that the code handles flows in cylindrical geometry successfully and resolves strong shocks within two to four computational cells. The advantages and limitations of the code are discussed.

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