Time-Resolved Flowfield Measurements in a Turbine Stage.
Abstract
Time-resolved flowfield measurements for a 0.5-meter diameter, high work transonic turbine have been completed in the MIT Turbine Blowdown Facility (TBF). Measurements were taken: to determine the blade-to-blade total temperature profile for comparison with predictions from the Euler turbine equation; to determine the effect of using time-averaged pressures to calculate turbine performance; and to provide a complete set of time-resolved turbine stage data. A preliminary objective (given a 6 kHz blade passing frequency) was to determine the frequency response characteristics of the instrumentation used to make the flowfield measurements. A shock tube was built for this purpose. Measurements were taken with high-frequency response instrumentation including a dual-hot-wire aspirating probe, a 'four-way' angle probe, and two cobra head total pressure probes incorporating silicon diaphragm pressure transducers. The aspirating probe is found to have a natural frequency of 15.5 kHz in the test gas with a damping ratio of 0.36; the angle probe a characteristic frequency of 45 kHz with a settling time of 18 usec. Both results are satisfactory for application in the TBF. The measured total temperature profile shows a peak-to-peak variation of 65 C (20%) and a characteristic frequency twice that of the blade passing frequency. (Theses)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1985
- Accession Number
- ADA158092
Entities
People
- J. L. Holt
Organizations
- Air Force Institute of Technology