Modelling a metal detector using eddy currents from Non-Destructive Testing

Click For Summary
SUMMARY

This discussion focuses on modeling a metal detector using eddy currents, specifically for an internship project. The system utilizes a coil energized by an oscillator to generate a magnetic field, with detection based on changes in coil impedance. The magnetic field created by the coil is described using Biot-Savart Law, while the induced voltage in the target is derived from Faraday's Law. The user seeks to determine the expression for the magnetic field induced by eddy currents, specifically whether it takes the form of Bind = B0eiwt.

PREREQUISITES
  • Understanding of Biot-Savart Law in electromagnetism
  • Familiarity with Faraday's Law of electromagnetic induction
  • Knowledge of coil impedance and its measurement techniques
  • Basic principles of eddy currents in conductive materials
NEXT STEPS
  • Research the mathematical modeling of eddy currents in conductive materials
  • Explore simulation tools for electromagnetic field analysis, such as COMSOL Multiphysics
  • Study the application of oscillators in electromagnetic systems
  • Investigate advanced topics in impedance measurement techniques
USEFUL FOR

Students and professionals in electrical engineering, particularly those involved in electromagnetic theory, metal detection technology, and non-destructive testing methodologies.

Sh_lm
Messages
2
Reaction score
2
Homework Statement
Modelling a metal detector
Relevant Equations
∇×E=− ∂/∂t(∇×B)
∇×B=μ0ε0∂/∂t(E)
I'm trying to model a metal detector for my internship project.
The system consist of one coil energised with an oscillator to create a magnetic field. The principle of the detection is by measuring the change in the coil impedance.
with biot et savart law the magnetic field create by the coil is expressed
1715018724594.png

where
Bem(r) : the magnetic field create by the coil
N : number of loops
Iem : current flowing through the coil
Rem : radius of the coil
r : distance from a given point in space to a point on the perimeter of the coil

The induced voltage in the target is given with faraday's law
1715019133773.png






where phi is the magnetic flux
I'm trying to find the expression of Bind the magnetic induced by eddy currents.
This is my results :
1715021033350.png

Now I've got a problem. Does Bind have a particular form? something like Bind = B0eiwt? or anything else? I need these results to start simulations so any help is welcomed thank you very much
 
Physics news on Phys.org

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 14 ·
Replies
14
Views
4K
  • · Replies 6 ·
Replies
6
Views
10K
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K