Effect of a normal shock wave on freestream total pressure fluctuations in a low-density mach 6 flow
Conference Paper
Overview
Identity
View All
Overview
abstract
An experimental investigation of the changes to freestream total pressure fluctuations in a low-density Mach 6 blowdown wind tunnel as it is convected through a normal shock wave was conducted. A Mach stem generated by the intersection of two oblique shock waves served as the normal shock wave. A fast-response pressure transducer mounted in a Pitot pressure probe was used to obtain total pressure fluctuations. Since measurements made upstream of the Mach stem were influenced by shock-shock interactions, measurements downstream of the Mach stem were compared to freestream measurements. Analyses of the total pressure fluctuation data provide information to changes to the total pressure fluctuation levels, axial integral length scale, and power spectral density estimates in the immediate vicinity of the normal shock wave. Amplification factors for noise and power spectra were overall modest compared to previous findings. Integral length scales were observed to slightly increase through the normal shock wave. Higher amplifications were generally observed for lower, incoming noise levels and for higher frequency content. Amplifications of power spectral density estimates qualitatively matched amplifications from a previous shock-turbulence intearction study in supersonic flow using hot-wire anemometers, suggesting that total pressure measurements, which are made with more robust instrumentation, may yield as useful information as fragile hot-wire sensors.
