A Pressure-Based Method for Turbulence Measurement in Hypersonic Flows

An improved method for performing measurements of turbulent quantities and spectra in hypersonic flows using a miniature pitot probe is presented. The probe is equipped with a high-frequency silicon pressure transducer, capable of withstanding the impact pressure and stagnation point heat flux realised by arc-driven or shock-driven hypersonic facilities. Turbulent velocity fluctuations are derived using a linearised hypersonic pitot relation. in the case of small turbulence intensity and assuming that the Strong Reynolds Analogy holds exactly. A discussion of the fundamental assumptions is provided, together with experimental and theoretical consideration of applicability and limits of the proposed method. Sample experimental results are presented in both low enthalpy air (Mach 6.1) and helium (Mach 7.3), showing that significantly small turbulent scales can be resolved in the higher Reynolds air runs, while no useful data was obtained in the case of helium.