{"id":6444,"date":"2026-07-10T13:50:21","date_gmt":"2026-07-10T18:50:21","guid":{"rendered":"https:\/\/commons.princeton.edu\/josephhenry\/?page_id=6444"},"modified":"2026-08-07T12:36:38","modified_gmt":"2026-08-07T17:36:38","slug":"amperes-galvanic-magnet-comsol-simulations","status":"publish","type":"page","link":"https:\/\/commons.princeton.edu\/josephhenry\/amperes-galvanic-magnet-comsol-simulations\/","title":{"rendered":"Ampere’s Galvanic Magnet & COMSOL Simulations 2026"},"content":{"rendered":"
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Prof. Henry’s replica of Ampere’s Solenoid<\/figcaption><\/figure>\n
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H. C. Cameron’s Sketch of Henry’s replica<\/figcaption><\/figure>\n

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Henry Clay Cameron’s notes from Joseph Henry’s_59th_Lecture<\/a>: \u00a0\u00a0 \u00a0Volume 15 (1820)<\/a><\/p>\n

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COMSOL Simulations \/\/ June-August 2026<\/h2>\n
Project 1: Permanent Bar Magnet and Electromagnet<\/h5>\n

This project aimed to model a 3-dimensional permanent bar magnet and an electromagnet in order to demonstrate the similarities between their magnetic field lines. Additionally, this serves as an introduction into working with the Magnetic Fields package. After assigning the proper physics, the field lines shown in both models were adjusted to better simulate the ideal diagrams in textbooks.<\/p>\n

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COMSOL simulation of the magnetic field lines of a bar magnet<\/figcaption><\/figure>\n

Bar Magnet Field Lines – June 29 2026 – COMSOL File Version 6.3<\/a><\/p>\n

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COMSOL simulation of the magnetic field lines of a solenoid around an iron core<\/figcaption><\/figure>\n

Electromagnet Field Lines – June 30 2026 – COMSOL File Version 6.3<\/a><\/p>\n

Project 2: Horseshoe Electromagnet and an Iron Bar<\/h5>\n

This project aimed to model a 3-dimensional horseshoe electromagnet in order to simulate its magnetic field lines. An iron rod was added to the simulation to demonstrate the principle of magnetic permeability and model magnetic field and flux concentration. A force calculation was done on the iron bar to plot magnetic force vs displacement of bar towards the electromagnet. The motion of the iron bar was accomplished by performing a parametric sweep of a range of the bar’s possible distances from the electromagnet. After assigning the proper physics, the field lines shown were adjusted to better simulate the ideal diagrams in textbooks.<\/p>\n

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COMSOL simulation of the magnetic field lines of an iron horseshoe electromagnet<\/figcaption><\/figure>\n
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COMSOL simulation of the magnetic field lines of an iron horseshoe electromagnet as an iron bar undergoes varying displacement towards electromagnet<\/figcaption><\/figure>\n
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Position 0<\/figcaption><\/figure>\n
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Position 1<\/figcaption><\/figure>\n
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Position 2<\/figcaption><\/figure>\n
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Position 3<\/figcaption><\/figure>\n
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Position 4<\/figcaption><\/figure>\n
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Electromagnetic force vs displacement of bar towards electromagnet<\/figcaption><\/figure>\n

Magnetic Force on a Moving Bar – July 7 2026 – COMSOL File Version 6.3<\/a><\/p>\n

Project 3: Henry’s Bell Ringer Experiment<\/h5>\n

This project aimed to model Joseph Henry’s bell ringer experiment. The exact specifications for the horseshoe electromagnet were taken from Henry’s documentation while the bell, permanent bar magnet, and pivot were constructed with estimated dimensions from models online. The permanent magnet has the north pole assigned to the top of the bar and the south pole to the bottom. The model simulates the rotation of a bar magnet as the direction of current flips from towards the right to towards the left, and in turn switching the location of the electromagnet’s north and south poles. In each case, the permanent magnet swings to the south pole of the electromagnet.<\/p>\n

These simulations were constructed by coupling the Magnetic Fields, with currents package with the Multibody Dynamics package. The electromagnetic torque over a range of angles was calculated first, and those values were then used in a new study to apply a “moment” and induce angular rotation of the bar. When the current was reversed, I re-ran the study to find new magnetic torque values at the same range of angles. In order to have the bar start where it might in a continuous study, I set the initial value for the bars rotation in the right-to-left current study to be equal to the final angle of the left-to-right current study. After assigning the proper physics, the field lines shown were adjusted to better simulate the ideal diagrams in textbooks.<\/p>\n

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COMSOL simulation of the magnetic field lines and flux as a bar magnet rotates towards the attracted pole of a horseshoe electromagnet<\/figcaption><\/figure>\n
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COMSOL simulation of the magnetic field lines and flux as a bar magnet rotates towards the repelled pole of a horseshoe electromagnet<\/figcaption><\/figure>\n

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Torque experienced by the permanent bar magnet over varying angles due to current flow from left to right<\/figcaption><\/figure>\n
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Torque experienced by the permanent bar magnet over varying angles due to current flow from right to left<\/figcaption><\/figure>\n
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COMSOL simulation of Henry’s bell ringer experiment; demonstrating the rotation of a bar magnet (north pole at the top) due to the magnetic field of an electromagnet created due to as current flow from left to right and then from right to left<\/figcaption><\/figure>\n
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COMSOL Simulation of Henry’s Bell Experiment; demonstrating the rotation of a bar magnet (north pole at the top) due to the magnetic field of an electromagnet created due to as current flow from left to right<\/figcaption><\/figure>\n
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COMSOL Simulation of Henry’s Bell Experiment; demonstrating the rotation of a bar magnet (north pole at the top) due to the magnetic field of an electromagnet created due to current flow from right to left<\/figcaption><\/figure>\n
Project 4: Albany Magnet<\/h5>\n

This project aimed to simulate the lifting force of the Albany Magnet. The specifications for the magnet, including the number of coils, diameter of the copper wire, height of magnet, radius of iron core, and current through each coil, were directly lifted from “The Innovators” by David Billington. The total volume of the weight lifted was estimated from diagrams within the book and photographs online. Applying a force calculation to a cast iron bar beneath the electromagnet and calculating for the total value using the Pythagorean theorem gives a total force value of 750.59N. This value should be verified with further experimentation.<\/p>\n

Raw and final calculated electromagnetic force values: albanyliftforce<\/a><\/p>\n

AlbanyMagnet – August 3 2026 – COMSOL File Version 6.3<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

      Henry Clay Cameron’s notes from Joseph Henry’s_59th_Lecture: \u00a0\u00a0 \u00a0Volume 15 (1820)       COMSOL Simulations \/\/ June-August 2026 Project 1: Permanent Bar Magnet and Electromagnet This project aimed to model a 3-dimensional permanent bar magnet and an electromagnet in order to demonstrate the similarities between their magnetic field lines. Additionally, this … Continue reading “Ampere’s Galvanic Magnet & COMSOL Simulations 2026”<\/span><\/a><\/p>\n","protected":false},"author":765,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-6444","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/pages\/6444","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/users\/765"}],"replies":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/comments?post=6444"}],"version-history":[{"count":96,"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/pages\/6444\/revisions"}],"predecessor-version":[{"id":6452,"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/pages\/6444\/revisions\/6452"}],"wp:attachment":[{"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/media?parent=6444"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/categories?post=6444"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/tags?post=6444"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}