Simcenter 3D Solutions Simcenter 3D Low Frequency Electromagnetics. MAGNET Solver - Solving: solver log file

Access and Usage

Information about the solution process is saved to a text file:

 

that can be accessed from the working directory, once the solve has completed.

 

Apart from containing global quantity information, the solver log file can be used as a diagnostic tool when problems are encountered at solving.

Name and location

The solver log file is called [Solution_Name]MAGNETSolverLog.txt and is stored in the working directory which is by default the directory containing the sim-file.

3D Solver log file contents

The solver log file display memory usage information whenever the elapsed time is written. The 3D solver log contents are described below.

No. of tetrahedra

This is the number of elements in the mesh (mesh elements are tetrahedral in shape).

No. of nodes

This is the number of nodes in the mesh of tetrahedra.

No. of Unary Faces

This is the number of faces of tetrahedra on which the potential is constrained to a constant.

Note: In MagNet, the potential is always zero.

No. of Binary Faces

This is the number of faces of tetrahedra on which an Even Periodic or Odd Periodic boundary condition is imposed.

No. of Edges

This is the number of edges in the mesh of tetrahedra.

No. of Field Nodes

This is the total number of degrees of freedom in the problem (the number of simultaneous equations to be solved).

No. of Binary Fnodes (pairs)

This is the number of pairs of degrees of freedom that have an Even Periodic or Odd Periodic boundary condition relation.

No. of Non Zeros

This is the number of non-zero entries in the global coefficient matrix.

No. of scalar tets

A scalar tet is a tetrahedron filled with non-conducting material

No. of vector tets

A vector tet is a tetrahedron filled with conducting material.

CG tolerance

This is the CG tolerance for the problem set in the Convergence tab of Solution Attributes. The default is 0.01%.

Newton tolerance

This is the Newton tolerance for the problem set in the Convergence tab of Solution Attributes. The default is 1%.

Interim estimate of maximum B in non-permeable, non-conducting fluid material = 29.1089

Interim estimate of maximum B in permeable, conducting or non-fluidmaterial = 1.21758

Before each Newton-Raphson step, MagNet generates some parameters of its latest field estimate for the magnetic flux density B(T). The calculations are approximate, and are not as accurate as the final values. They may be useful, however, in tracking the convergence in a nonlinear solution.

Newton 2:199 C.G. steps: size = 0.506261%; target = 0.1%

If the simultaneous equations are non-linear, the iterative technique can be the Newton-Raphson method or the successive substitution method. Each step of either of these methods involves the solution of a complete set of linear equations by the Conjugate Gradient (CG) method.

"199 CG steps" indicates how many conjugate gradient steps were required to solve the linear system of equations.

"Change" indicates the relative change in the solution vector between the current Newton step and the previous Newton step.

"Target" is the percent change that must be reached before the non-linear equations are deemed solved.

Note: For linear problems, there is just one Newton step.

For static solutions (not in the attached example), you can see

Magnetic energy in the model =2.46259e+006 Joules

Magnetic co-energy in the model =2.46259e+006 Joules

This is the magnetic energy and co-energy stored in the whole model for static solutions. For linear solutions, energy and co-energy are identical.

Instantaneous magnetic energy in the model =-8.78887 Joules

Instantaneous magnetic co-energy in the model =10.5669 Joules

This is the magnetic energy and co-energy stored in the whole model for the current time step for transient solutions. You should request to track it in Solver Parameters of the solution:

For time-harmonic solutions,  the magnetic energy stored in the whole model is output, like this (not in the attached example):

Time-averaged magnetic energy stored in the model = 2.46259e+006 Joules

For each label corresponding to a conducting material, the time-harmonic solver calculates the time-averaged energy loss through Ohmic heating (not in the attached example):

Time-averaged Ohmic power dissipated in label _ = 1.94756E+03 Watts

For coil number 1

Flux linkage = 0.0153041 Webers

MagNet reports the flux linkage for each coil in the model for static, time-harmonic and transient solutions (for each time step). Flux linkage is calculated for each coil even if the current in the coil is zero.

Terminal voltage = 0.00000E+00 1.78640E+04 V

The time-harmonic solution reports the net voltage for each current-driven coil (not in the attached example).

 Temperature values for each body:

    Average temperature over component: 20 C

    Minimum temperature over component: 20 C

    Maximum temperature over component: 20 C

Body 1 consists of the following components:

Linear Actuator Assembly_sim1,Magnets/3d_mesh(1)

                     Linear Actuator Assembly_sim1,Magnets/3d_mesh(2)

                     Linear Actuator Assembly_sim1,Magnets/3d_mesh(3)

                     Linear Actuator Assembly_sim1,Magnets/3d_mesh(4)

                     Linear Actuator Assembly_sim1,Magnets/3d_mesh(5)

                     Linear Actuator Assembly_sim1,Magnets/3d_mesh(6)

                     Linear Actuator Assembly_sim1,Virtual/3d_mesh(22)

Force on body 1 is

-0.243772,-0.191966,-85.8953 N.

Torque about the origin on body 1 is

-0.000191831,-0.00541287,0.0419963 N.m.

This is the force and torque calculation for bodies in the model for static, time-harmonic and transient (for each time step) solutions. The values given in the solver log are the Cartesian components of the force and torque vectors, in the same coordinate system that was originally used to define the geometry of the problem.