Total-pressure-tube averaging in pulsating flows.A number of total-pressure tubes were tested in a nonsteady flow generator in which the fraction of period that pressure is a maximum is approximately 0.8, thereby simulating turbomachine-type flow conditions. The tests were performed at a pressure level of 1 bar, for Mach numbers up to near 1, and frequencies up to 3 kHz. Most of the tubes indicated a pressure which was higher than the true average. Organ-pipe resonances which further increased the indicated pressure were encountered within the tubes at discrete frequencies. There was no obvious combination of tube diameter, length, and/or geometry variation used in the tests which resulted in negligible averaging error. A pneumatic-type probe was found to measure true average pressure, and is suggested as a comparison instrument to determine whether nonlinear averaging effects are serious in unknown pulsation profiles.
Document ID
19730049806
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Krause, L. N. (NASA Lewis Research Center Cleveland, Ohio, United States)
Date Acquired
August 7, 2013
Publication Date
January 1, 1973
Subject Category
Instrumentation And Photography
Meeting Information
Meeting: International Aerospace Instrumentation Symposium