Kettering University reduces undesired EV motor noise
In today's automotive industry, it is apparent that electric vehicles (EVs) are the future of mobility. Internal combustion is out. As a result, manufacturers are looking for better ways to develop and design electric engines. One might assume those conducting research on EVs to be looking for ways to enhance long distance performance; however, in this instance, the issue is less about optimizing travel and more about and enhancing comfort. In electric vehicles, high frequency noises from tires or electrical accessories become more prominent. As a result, Kettering Universities engineering students have been studying the causes of high-frequency vibrations within e-motors.
The study was divided into three parts: electromagnetic analysis, structural analysis, and acoustic analysis. Kettering's goal was to develop a cost-effective method for reducing noise caused by these vibrations. The engineers began by analyzing the sound generated by an electromagnetic model of a three-phase induction motor via simulation. To validate these simulation results, the engineers had to conduct an acoustic test on a small-scale general-purpose motor.
A Kettering University engineering student conducting a sound measurement on a general purpose motor.
Kettering's engineers utilized Simcenter Testlab during both the structural and acoustic analysis on the motor. The acoustic analysis assisted engineers in identifying frequencies at which sound pressure peaked and offered insight as to how these could be isolated. The test involved the creation of a spherical mesh with microphones around the motor. These microphones were placed approximately one meter from the motor (as seen in pink below).
Field Point Mesh (Microphones in Pink)
Eventually, an operational modal analysis visualized specific motor vibrations at certain points within the motor. It was found that frequencies were generating from within the motor's housing and its end brackets. The engineers found that by using modified end brackets, they could simplify the process of isolating frequencies that amplify perceived sound.
Operating Deflection Shapes of End Bracket
If successful, Kettering's study could provide electric motor manufacturers' a new way of reducing undesired motor noise without adding additional weight. For more information regarding how Kettering students and researchers are using Simcenter, click here.