Study of cluster formation and its effects on Rayleigh and Raman scattering measurements in a Mach 6 wind tunnelUsing a frequency-doubled Nd-YAG pulsed laser and a single-intensified CCD camera, Rayleigh scattering measurements have been performed to study the cluster formation in a Mach 6 wind tunnel at NASA Langley Research Center. These studies were conducted both in the free stream and in a model flow field for various flow conditions to gain an understanding of the dependence of the Rayleigh scattering (by clusters) on the local pressures and temperatures in the facility. Using the same laser system, simultaneous measurements of the local temperature have also been performed using the rotational Raman scattering of molecular nitrogen and determined the densities of molecular oxygen and nitrogen by using the vibrational Raman scattering from these species. Quantitative results are presented in detail with emphasis on the applicability of the Rayleigh scattering for obtaining quantitative measurements of molecular densities both in the free stream and in the model flow field.
Document ID
19910058924
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Shirinzadeh, B. (NASA Langley Research Center Hampton, VA, United States)
Hillard, M. E. (NASA Langley Research Center Hampton, VA, United States)
Blair, A. B. (NASA Langley Research Center Hampton, VA, United States)
Exton, R. J. (NASA Langley Research Center Hampton, VA, United States)