Compact dynamometer system that can accurately determine propeller performance

A N advanced, compact propeller dynamometer measurement system has been developed that determines propeller performance values to within ±5% error. Propeller thrust is found to within ±3.2% with a linearly variable differential transformer that measures dynamometer shaft extensions, torque to within ±1.5% using an optical torque transducer, and rpm to within ±0.003% by an optical digital resolver. The system was tested in a low-speed wind tunnel using marine and remotely piloted vehicle propellers to assess its operational capability. Results reveal that the thrust and torque coefficients and efficiency can be determined to within ±3.45, ±2.08, and ±4.2%, respectively.