Influence of Small Steps on Wall Pressure Fluctuation Spectra Measured on Tu-144LL Flying Laboratory

摘要

Results of analyzing flight-test data of pressure-fluctuation fields in front of forward-facing steps and behind backward-facing steps are presented. The range of dimensionless step heights (normalized by boundary-layer displacement thickness) in the flight test was 0.042-0.236. The flight tests covered a mach-number range from 0.57 to 1.97. In the mach-number ranges covered by wind-tunnel tests (0.57 to 0.78 and 1.5 to 2) data agree very well with the flight data. Very importantly, the flight-test data fill in the gap previously existing for small-step pressure-fluctuations in the range of mach 0.78 to 1.5. Increased pressure-fluctuations were observed in the transonic region.