Mean flow and noise measurements in a Mach 3.5 pilot quiet tunnelThe use of Mach 3.5 two-dimensional rapid expansion nozzle for wind tunnel testing at supersonic speeds and low noise conditions encountered in high altitude flights is described. The supersonic pilot quiet tunnel is located at the NASA Langley Research Center and a description of the facility is provided, along with instrumentation and noise measurement test data at 30, 50, and 75 psia. The mean pitot pressure distributions, rms noise levels, the effect of unit Reynolds number, wall waviness, wall contaminants, and the effects of closing the bleed valve are analyzed. Typical laminar and turbulent spectra are presented, along with a summary of the effect of slot throat adjustment on the power spectra. Comparisons are made of the power spectra with the bleed valve open and closed, and of the rms fluctuating pressures with levels from conventional nozzles, and the performance capabilities are evaluated for use in transition studies.
Document ID
19820041122
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Beckwith, I. E. (NASA Langley Research Center Hampton, VA, United States)
Moore, W. O., III (NASA Langley Research Center Hampton, VA, United States)