Direct Drive Viscous Shear Water Dynamometers for Large Gas Turbines

After several years of negative experience using conventional commercial water dynamometers directly driven at free power turbine speed, the author's company undertook an in-house design of a noncavitating dynamometer with the objectives of long life and low maintenance cost. The paper is a review of the design and performance of the dynamometer, utilizing smooth disk and stator elements and employing viscous shear variable immersion torque control.