Ansys Maxwell Magnetic Transient Help

Click For Summary

Discussion Overview

The discussion revolves around simulating a linear eddy current brake using Ansys Maxwell. Participants explore the modeling of a magnet moving above an aluminum plate and the associated forces, particularly focusing on the drag force and the effects of eddy currents. The conversation includes technical details about the setup, equations, and numerical modeling choices.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant describes their model setup, including the motion of a magnet and the configuration of the aluminum plate, and notes the observed forces.
  • Another participant inquires about the equations used to calculate the force, indicating a need for clarity on the underlying physics.
  • There is a suggestion to consider simpler models, such as strips or coils, to facilitate analysis and to question how magnet fringing fields are addressed in the current setup.
  • A participant expresses uncertainty about selecting equations within the software and mentions that the force is derived from a parameter applied to the magnet object.
  • Participants emphasize the importance of understanding the physics behind the numerical model chosen for simulating eddy current braking.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the modeling approach or the equations to use. There are multiple viewpoints regarding the adequacy of the current model and the necessity of understanding the underlying physics.

Contextual Notes

Participants express uncertainty regarding the selection of equations and the handling of specific physical phenomena, such as magnet fringing fields, which may affect the simulation results.

Khang Vu
Messages
3
Reaction score
0
I am trying to simulate a linear eddy current brake. To do this, I am modeling my brake as a single magnet moving above an aluminum plate. I plan to measure the drag force on this magnet and calculate my braking force as a superposition of single magnets. Here's my current setup:

Model:
A single rectangular magnet moving along the edge of an aluminum plate such that its cross section is fully covered by the plate's at a top view. My band is a bigger rectangular prism surrounding the magnet and a container object that holds the magnet. The model takes whatever in the container object as a single rigid body; that's what should happen from what I've read online. The magnet's magnetic field is aligned to be in the z direction (towards and perpendicular to the top face of the plate).

Motion setup:
The magnet is moving at a constant speed parallel to the edge of the plate.

Excitations:
The model only accounts for eddy current effects in the plate. It does not account for any eddy current effects in the permanent magnet.

Mesh Operations:
-Skin depth mesh on the plate. I used a frequency of 2000 Hz. This was calculate from the fact that the magnet is moving at 120 m/s
-Internal length mesh inside the plate.
-Internal length mesh inside the band.
-internal length mesh inside the magnet

Currently, I am getting 0 drag force on the magnet and oscillating lateral and lift force.
 
Engineering news on Phys.org
What equation are you using to solve for the force?
 
Paul Colby said:
What equation are you using to solve for the force?
I have no idea where to pick equations, but I chose the magnetic transient solver for this problem. The force is given to me by applying a parameter to the magnet object.
 
Khang Vu said:
I have no idea where to pick equations, but I chose the magnetic transient solver for this problem. The force is given to me by applying a parameter to the magnet object.

Well, it's kind of important to understand the underlying physics in choosing a numerical model. Eddy current breaking is due to power dissipation of the induced current in the conductor. Maybe a simpler model like strips or a coil replacing the aluminum plate might be simpler to analyze by hand? How are the magnet fringing fields handled? My bet is you've left something out if you are getting zero breaking force.

Also, what software is being used?
 
Paul Colby said:
Well, it's kind of important to understand the underlying physics in choosing a numerical model. Eddy current breaking is due to power dissipation of the induced current in the conductor. Maybe a simpler model like strips or a coil replacing the aluminum plate might be simpler to analyze by hand? How are the magnet fringing fields handled? My bet is you've left something out if you are getting zero breaking force.

Also, what software is being used?
I am using Ansys Maxwell. I don't really see an option to choose the equations behind the model. All I really see is an option to pick which solver to use.
 

Similar threads

Replies
1
Views
1K
Replies
10
Views
6K
Replies
12
Views
3K
  • · Replies 2 ·
Replies
2
Views
1K
Replies
2
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 2 ·
Replies
2
Views
7K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 1 ·
Replies
1
Views
1K