[Getdp] Some questions

JORGE MIAJA HERNANDEZ j.miaja at alumnos.upm.es
Wed Feb 6 14:37:06 CET 2019

```Dear all,

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,

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?

expression 1:
Integral { [ dhdb[{d a}] * Dof{d a} , {d a} ];
In Vol_NL_Mag; Jacobian Vol; Integration Gauss_v; }
Integral { [ - dhdb[{d a}] * {d a} , {d a} ];
In Vol_NL_Mag; Jacobian Vol; Integration Gauss_v; }

expression 2:
Integral { JacNL[dhdb[{d a}] * Dof{d a} , {d a} ];
In Vol_NL_Mag; Jacobian Vol; Integration Gauss_v; }

2- I have tried testing time loop resolutions, in order to set the
InitSolution, I tried defining a constraint of type InitFromResolution,
Case {
{ Region Sur_boundary; Type InitFromResolution; NameOfResolution
dir_a; }
}
// with the resolution block being (supposedly*):
{ Name dir_a;
System {
{ Name B; NameOfFormulation fixBoundary; DestinationSystem A;}
}
Operation {
Generate B; Solve B; TransferInitSolution B;  // TransferSolution B;
}
}
// the formulation being as follows:
{ Name fixBoundary;
Quantity { { Name a; Type Local; NameOfSpace VecPotA; } }
Equation {
Integral { [ Dof{a} , {a} ];
In Sur_boundary; Jacobian Sur; Integration Int; }
Integral { [ dirBoundary[] , {a} ]; // dirBoundary being a vector
[0,0, X] where X could be a time function (see question 3)
In Sur_boundary; Jacobian Sur; Integration Int; }
}
}

*supposedly, since according to the documentation, TransferInitSolution
is used along with "InitFromResolution", however, GetDP shows an error
that reads: "Unknown type of Operation: TransferInitSolution"
(I downloaded the latest version available on January the 14th). Should
I get exactly the same result if I use TransferSolution in this line?

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?
a) define a time function dependen on variable \$Time
b) create a constraint of type AssignFromResolution
c) at each time step call UpdateResolution so that the constraint is
calculated again with the AssignFromResolution block

I am greatly grateful for and really appreciate all your help provided,
as well as for the software you have developed,
Really looking forward to learning more about this powerful tool,

best regards,

--
JORGE MIAJA HERNANDEZ
Universidad Politecnica de Madrid

```

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