Flywheel Standard Issued

A new standard, ANSI/AIAA S-096-2004, for flywheels used in space has been issued. This standard addresses the design, fabrication, testing and inspection of flywheel rotors used in space applications. On earth, flywheels are typically used for energy storage and load leveling. While they serve the same functions in space, they have the additional advantage in space of being useful for attitude control. Richard Thompson of the University of Texas Center for Electromechanics was a member of the committee that developed the standard. In addition, the standard incorporates some of the research results and test approaches first developed and documented at the University. For further information, contact Richard Thompson.

Electric Ship Power Systems

The Navy is moving toward the use of all electric ships including the use of an electric gun to replace the large guns currently used on warships. CEM staff members performed an analytical study that shows some advantages to the ship power system of using pulsed alternators as the power supplies for the electric guns on these future ships. The study showed that a pulsed alternator that stored 10 shots was smaller and lighter than a capacitor power supply system that stored a single shot. Moreover, the pulsed alternator could be used as flywheel energy storage to enhance power system performance during the majority of the ship’s life when the guns were not needed. This work was summarized in the paper “An Electromagnetic Gun Power Supply as a Component of an Electric Ship Power System” by R. Hebner, J. Pappas, J. Kitzmiller, K. Davey, J. Herbst, A. Ouroua, and J. Beno. The paper was presented at the High Powered Weapon Systems for Electric Ship 2004 in Annapolis, MD, December 2004. For further information, please contact R. Hebner.

Copper Measurement in Coolant System

A recent study of water as a coolant in an electrical machine has shown that flow velocity and area of coolant tube surface both affect the production of copper in the system. A recent paper, “Limitations on water cooling of rotors and stators in intermittent duty machines,” By C. Hearn, J. Hahne, and R. Hebner in the 2004 Annual Report of the Conference on Electrical Insulation and Dielectric Phenomena, shows that for grounded systems the processes are consistent with classical mobility determinations for copper in water. This investigation provided necessary baseline data for an assessment of the behavior on time scales comparable to the intrinsic time constant of the water. For further information, please contact R. Hebner.