Designing Motors with a Coupled Simulation Approach

Last year, the company I work for — CFX Berlin (an ANSYS channel partner) — was selected as runner-up in the ANSYS Hall of Fame competition. The application we submitted was about designing motors with a coupled simulation approach, based on work we performed with a customer. When ANSYS asked us to participate in a webinar on this topic, we were happy to share what we learned.

ANSYS Hall of Fame 2013 runner-up CFX Berlin

The company we supported was Anhaltische Elektromotorenwerk Dessau GmbH (AEM Dessau), an electrical motor factory in Germany. The business is shifting from traditional development processes to true simulation-based product development for rotating electrical machines. The integrated electromagnetics and fluid dynamics (CFD) software from ANSYS makes it possible to perform real multiphysics calculations for these machines.

I’ll give you a little background on this project. AEM Dessau has more than 60 years of experience in producing rotating electrical machines. The company produces user-friendly, innovative and safe products that meet the highest standards of quality and reliability.  It is not only a supplier but partners with their customers to help them compete in this market space.

To accomplish this, engineers at AEM Dessau use ANSYS RMxprt and ANSYS Maxwell to design electrical machines, including three-phase synchronous generators and three-phase asynchronous motors.

For this project, AEM Dessau and CFX Berlin used ANSYS CFD software to generate an accurate thermal model of a complete electric asynchronous machine, which then was validated by extensive measurements. This application investigated the cooling of the asynchronous machine for two loading points. Due to the encapsulated design of the motor, the team needed to account for forced convection both inside the housing and on the outer cooling ribs. This rotational speed and the distribution of ohmic losses were the main input parameters. These losses were built into the CFD model as heat sources in the stationary and rotating components of the machine.

Because of the complexity of the windings, it was not practical to describe them geometrically. Instead, we used a porous media model that also took into account the heat flux between solid and fluid. Measurements of velocity and temperature fields were carried out showing good agreement with the results of the simulation. This work delivered a reliable simulation model to AEM Dessau for further optimization of fan design and internal thermal management.

Realistic analysis of complex physical phenomena requires coupled simulation. If you’d like to learn more about how AEM Dessau and CFX Berlin used ANSYS CFD software to generate an accurate thermal model of a complete electric asynchronous machine, the webinar is on August 20th entitled “Numerical Simulation of the Flow and Temperature Field in a Rib-Cooled Electric Motor.” Please register and join us!

Editors Note: 
CFX Berlin offers customized solutions for all engineering areas, including mechanical, civil and environmental, electrical, biomedical, chemical and material, and geothermal. Projects with industrial partners help make these companies’ products more reliable and more efficient; and provide insights into product-specific processes to improve these partners’ businesses. Customers include BMW, Group Bosch, GEA, Infinion, MAN and Mahle. Visit CFX Berlin’s YouTube Site.