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start of docs for e-formulation
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@@ -19,7 +19,7 @@ Electromagnetic phenomena are governed by Maxwell's equations. They describe the
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Fourier Transform Convention
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----------------------------
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In order to examine Maxwell's equations in the frequency domain, we must first define our choice of harmonic time-dependence by choosing a Fourier transform convention. We use the \\(e^{i \\omega t} \\)\\ convention, so we define our Fourier Transform pair as
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In order to examine Maxwell's equations in the frequency domain, we must first define our choice of harmonic time-dependence by choosing a Fourier transform convention. We use the \\(e^{i \\omega t} \\) convention, so we define our Fourier Transform pair as
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.. math ::
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F(\omega) = \int_{-\infty}^{\infty} f(t) e^{- i \omega t} dt \\
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@@ -76,7 +76,7 @@ For a more complete discussion of physical properties see `GPG <http://www.eos.u
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Quasi-static Approximation
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--------------------------
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For the frequency range typical of most geophysical surveys, the contribution of the electric displacement is negligible compared to the electric current density. In this case, we use the \\(\\emph{Quasi-static approximation}\\) and assume that this term can be neglected, giving
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For the frequency range typical of most geophysical surveys, the contribution of the electric displacement is negligible compared to the electric current density. In this case, we use the Quasi-static approximation and assume that this term can be neglected, giving
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.. math ::
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\nabla \times \vec{E} = -i \omega \vec{B} \\
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@@ -9,16 +9,13 @@ def omega(freq):
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class BaseProblemFDEM(Problem.BaseProblem):
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"""
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We start with the E-formulation Maxwell's equations in the frequency domain:
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.. math ::
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We start by looking at Maxwell's equations in the electric field \\(\\vec{E}\\) and the magnetic flux density \\(\\vec{B}\\):
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.. math::
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\\nabla \\times \\vec{E} + i \\omega \\vec{B} = 0 \\\\
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\\nabla \\times \\mu^{-1} \\vec{B} - \\sigma \\vec{E} = \\vec{J_s}
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By eliminating the magnetic flux density using
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.. math ::
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\\vec{B} = \\frac{-1}{i\\omega}\\nabla\\times\\vec{E},
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we can write Maxwell's equations as a second order system in \\ \\vec{E} \\ only:
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.. math ::
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\\nabla \\times \\mu^{-1} \\nabla \\times \\vec{E} + i \\omega \\sigma \\vec{E} = \\vec{J_s}
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"""
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def __init__(self, model, **kwargs):
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Problem.BaseProblem.__init__(self, model, **kwargs)
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@@ -169,7 +166,21 @@ class BaseProblemFDEM(Problem.BaseProblem):
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class ProblemFDEM_e(BaseProblemFDEM):
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"""
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Solving for e!
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By eliminating the magnetic flux density using
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.. math::
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\\vec{B} = \\frac{-1}{i\\omega}\\nabla\\times\\vec{E},
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we can write Maxwell's equations as a second order system in \\ \\vec{E} \\ only:
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.. math::
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\\nabla \\times \\mu^{-1} \\nabla \\times \\vec{E} + i \\omega \\sigma \\vec{E} = \\vec{J_s}
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This is the definition of the Forward Problem using the E-formulation of Maxwell's equations.
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"""
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solType = 'e'
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