The established approach would have been to change the design by either adding copper and steel or changing the ventilation method, build a new prototype and evaluate the temperature reduction achieved. This process required approximately ten iterations, each taking close to a month, in order to obtain an acceptable design. Because of the slow pace and high cost of this approach, Emerson decided to use CFD instead. Emerson engineers chose CFX-TASCflow from AEA Technology to create a virtual prototype based on the original design.

Everyone was happy with the new design but management decided to remove the shell that enclosed the windings to reduce manufacturing costs. The design had to be substantially modified, but, because engineers had already gained a clear understanding of the airflow through the motor, the cooling problem was solved within a couple of weeks. Engineers designed a concentric cylinder for the end shield that serves to contain the airflow against the stator, drawing it across the windings and into the fan before it is exhausted from the motor. CFX showed that the fan could be made considerably smaller and that it would work more efficiently if it were changed to pull rather than push air through the motor.

CFD results were used to guide the entire design process and prototypes were built only at key decision points to validate the analysis. CFD dramatically reduced our time to market by providing understanding that the engineers couldn't have gained from experiments and by eliminating the time-consuming building of prototypes. The project was completed in about eight months while the trial-and-error method would have taken several years. The superior insight provided by CFD helped Emerson to produce a considerably better design; the new design has optimal ventilation, which allows for minimal copper and steel usage thereby reducing costs. The virtual prototyping method clearly provides a superior way to develop electric motors.