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<div class="">On 6 Feb 2019, at 14:37, JORGE MIAJA HERNANDEZ <<a href="mailto:j.miaja@alumnos.upm.es" class="">j.miaja@alumnos.upm.es</a>> wrote:</div>
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<div class="">Dear all,<br class="">
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I have been reading the documentation and creating some magneto-static and magneto-dynamic simple tests and there are a few things I cant quite understand, I was hoping somebody could help me clarify these points,<br class="">
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1- taking a look at several non-linear examples, I have noticed two different ways to implement the correction term that deals with the non-linearity of the system using Newton-Raphson, are these two expressions exactly identical? Or does one provide better
results than the other?<br class="">
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expression 1:<br class="">
<span class="Apple-tab-span" style="white-space:pre"></span>Integral { [ dhdb[{d a}] * Dof{d a} , {d a} ];<br class="">
In Vol_NL_Mag; Jacobian Vol; Integration Gauss_v; }<br class="">
Integral { [ - dhdb[{d a}] * {d a} , {d a} ];<br class="">
In Vol_NL_Mag; Jacobian Vol; Integration Gauss_v; }<br class="">
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expression 2:<br class="">
<span class="Apple-tab-span" style="white-space:pre"></span>Integral { JacNL[dhdb[{d a}] * Dof{d a} , {d a} ];<br class="">
In Vol_NL_Mag; Jacobian Vol; Integration Gauss_v; }<br class="">
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<div>Have a look at:</div>
<div><a href="http://onelab.info/wiki/Nonlinear_problems_in_GetDP" class="">http://onelab.info/wiki/Nonlinear_problems_in_GetDP</a></div>
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<div>Both approaches are equivalent.</div>
<div>There is a difference in the resolution part in the pro file though.</div>
<div>The first one uses a let’s say by hand defined loop: While that stops with a condition defined by the user.</div>
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<div>The second one goes with the function IterativeLoopN.</div>
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<div class="">2- I have tried testing time loop resolutions, in order to set the InitSolution, I tried defining a constraint of type InitFromResolution,<br class="">
Case {<br class="">
{ Region Sur_boundary; Type InitFromResolution; NameOfResolution dir_a; }<br class="">
}<br class="">
// with the resolution block being (supposedly*):<br class="">
{ Name dir_a;<br class="">
System {<br class="">
<span class="Apple-tab-span" style="white-space:pre"></span><span class="Apple-tab-span" style="white-space:pre"></span>{ Name B; NameOfFormulation fixBoundary; DestinationSystem A;}<br class="">
}<br class="">
Operation {<br class="">
<span class="Apple-tab-span" style="white-space:pre"></span><span class="Apple-tab-span" style="white-space:pre"></span>Generate B; Solve B; TransferInitSolution B; // TransferSolution B;<br class="">
}<br class="">
}<br class="">
// the formulation being as follows:<br class="">
{ Name fixBoundary;<br class="">
<span class="Apple-tab-span" style="white-space:pre"></span>Quantity { { Name a; Type Local; NameOfSpace VecPotA; } }<br class="">
<span class="Apple-tab-span" style="white-space:pre"></span>Equation {<br class="">
<span class="Apple-tab-span" style="white-space:pre"></span><span class="Apple-tab-span" style="white-space:pre"></span>Integral { [ Dof{a} , {a} ];<br class="">
<span class="Apple-tab-span" style="white-space:pre"></span><span class="Apple-tab-span" style="white-space:pre"></span>In Sur_boundary; Jacobian Sur; Integration Int; }<br class="">
<span class="Apple-tab-span" style="white-space:pre"></span><span class="Apple-tab-span" style="white-space:pre"></span>Integral { [ dirBoundary[] , {a} ]; // dirBoundary being a vector [0,0, X] where X could be a time function (see question 3)<br class="">
<span class="Apple-tab-span" style="white-space:pre"></span><span class="Apple-tab-span" style="white-space:pre"></span>In Sur_boundary; Jacobian Sur; Integration Int; }<br class="">
<span class="Apple-tab-span" style="white-space:pre"></span>}<br class="">
}<br class="">
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*supposedly, since according to the documentation, TransferInitSolution is used along with "InitFromResolution", however, GetDP shows an error that reads: "Unknown type of Operation: TransferInitSolution"<br class="">
(I downloaded the latest version available on January the 14th). Should I get exactly the same result if I use TransferSolution in this line?<br class="">
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3- In what cases would the "UpdateConstraint" operation be useful? If, for instance, I want to set up a Dirichlet boundary constraint that changes over time, how could I do it? would this work?<br class="">
a) define a time function dependen on variable $Time<br class="">
b) create a constraint of type AssignFromResolution<br class="">
c) at each time step call UpdateResolution so that the constraint is calculated again with the AssignFromResolution block<br class="">
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<div>UpdateConstraint is useful when the links between the unknowns change in time, e.g. you may have that in case of movement. </div>
<div>AssignFromResolution can be useful for computing sources, e.g. at the level of the boundary, or for initialising a time domain solution.</div>
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<div>Best</div>
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Ruth<br class="">
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I am greatly grateful for and really appreciate all your help provided, as well as for the software you have developed,<br class="">
Really looking forward to learning more about this powerful tool,<br class="">
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best regards,<br class="">
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-- <br class="">
JORGE MIAJA HERNANDEZ<br class="">
Universidad Politecnica de Madrid<br class="">
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