The propulsion wind tunnel (PWT) at the Arnold Engineering Development Center (AEDC) is known for the four powerful motors that drive its compressors.
In an effort to keep the wind tunnel running at capacity, the stator for the M4 motor has been replaced as part of a major investment program for PWT. The previous stator had been in use since the motor was put into service in the mid-1950s and at the time was the world’s largest electric motor on a horizontal shaft, capable of producing 83,000hp.
The PWT Main Drive M4 Motor Stator Replacement Project was approved at a cost of US$5.5 million and awarded to TECO Westinghouse of Round Rock, Texas. The motor itself was originally manufactured by Westinghouse East Pittsburgh Plant in Philadelphia, Pennsylvania.
“The function of the stator is to rotate the main compressors for the PWT 16ft transonic and 16ft supersonic wind tunnels,” said Joseph Capps, PWT plant system architect. “There is a sister motor of the same 83,000hp design, along with two other 60,000hp motors that are connected via a common drive shaft to provide the required torque to rotate the wind tunnel compressors during testing. In the mid-1950s the two sister 83,000hp motors were the largest horizontal-shaft motors ever built.”
The design of the work took about four months. Construction of the stator frame and core components took approximately eight months.
In parallel with construction of the new steel frame, copper coil fabrication was done in the UK by Sulzer/Dowding & Mills. TECO began installing and winding the core of the stator in August 2015 and worked a three-shift operation until the first of December 2015.
“With completion of the installation work [at AEDC], the M4 motor was operated at maximum load on April 19 to verify that the stator could produce its nameplate rating,” Capps said. ” Installation of the new stator for the PWT main drive will enable it to return to its maximum torque capability.