Low Frequency Electromagnetic Analysis and Its Structural and Thermal Effects

This month we will focus on applications and workflows resulting from the electromagnetic (EM) solution available through the Altair Partner Alliance (APA). Altair customers have access to the world’s leading technologies for electromagnetic applications, which expand to modern electrical and communication systems as well, with FEKO covering the high frequency problems and JMAG from JSOL covering the low frequency domain.

When talking about solving EM problems, FEKO is generally good down to the MHz range and has a special implementation

(low-frequency stabilization) that can work down to kHz range. Typical applications spanning different industries involve antenna design for communication, radiation patterns study, and hazard analysis, to name a few. Complete information can be found on the FEKO Applications page. Make sure to also check out the blog article on the role of EM simulations versus measurements.

For very low frequency applications (all the way to zero frequency), such as motors, motor drive systems, induction heating, transformers, etc., JMAG works best. JMAG provides an excellent design tool to improve the performance and aid in cost reduction during the product development cycle of electric motors and generators. Other good examples are air-conditioners, washing machines, vacuums, home appliances and many automotive applications including electrical devices for opening and closing windows, positioning and reclining seats, power steering and engine control.

Electromagnetism in low frequency applications produces forces and vibrations that need to be managed for structural integrity and noise, as well as EM losses that are dissipated as heat. Designers have to deal with these structural and thermal effects when dealing with motors and generators in addition to tuning the performance characteristics of concerned electrical devices. Electric and hybrid powertrains bring new challenges to design of noise, vibration and harshness for vehicles. The engine noise can mask the majority of the sources of other noise, and in the absence or inoperative state of an internal combustion engine (ICE), an audible sound is heard that may need to be mitigated. While the electric and hybrid vehicles are, in general, quieter than ICE driven cars, a detailed study of the dynamics and noise sources within the electric powertrain systems can help understand customers’ perception of quality and acceptance.

A workflow showing JMAG and OptiStruct minimizing radiated noise for a motor housing with topology optimization is shown above. The details of the process can be found from the referenced document. By transferring the electromagnetic forces from JMAG to OptiStruct, vibration noise within electrical equipment can be assessed and minimized. The unique optimization techniques in OptiStruct further help in achieving optimal designs of reduced weight, improved structural behavior, or minimized noise effects in these systems.

Electromagnetic simulation results can be coupled to thermal and fluid flow analysis as well. The electromagnetic losses from JMAG can be mapped as heat sources in AcuSolve for a subsequent thermal/flow analysis to study the cooling effectiveness, for example. JMAG Manager in AcuConsole accomplishes the mapping.

Alternatively, as electromagnetic properties are temperature dependent, AcuSolve can output temperature data that JMAG can read in order to perform an electromagnetic analysis.

These couplings enable engineers to study the electromagnetic effects on the structural and thermal behavior of systems.

Questions or comments? Email apatech@altair.com

To download JMAG and to learn more, click here.

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Sridhar Ravikoti

Technical Director - Global Partner Programs at Altair

Sridhar Ravikoti is the Technical Director of Global Partner Programs at Altair. He has been with Altair since 2000, gaining experience in engineering product development and software program management. In his current role as a technical lead for the Altair Partner Alliance, Sridhar drives a synergetic relationship between Altair offering and its Partners. He holds a Bachelor’s degree from Osmania University in India, and a Master’s degree from the University of Nebraska-Lincoln, with a major in Mechanical Engineering and a minor degree in Applied Mechanics.

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