Study of the structure of turbulent underexpanded supersonic jets by laser transillumination

Abstract

The paper analyzes the spatial distribution of the average air density in a supersonic jet based on the results of laser transillumination. The algorithm to retrieve the average air density from transverse (to the jet axis) deviations of the transilluminating wavefront was tested in experiments on the Vertical jet setup of ITAM SB RAS. The results of retrieval are compared with the known literature data of contact measurements and with results of numerical simulation. The good sensitivity of local wavefront tilts to oscillations in the air density at frequencies of discrete acoustic tones has been demonstrated. This opens up the possibility of experimental study of the spatial structure of air density inhomogeneities in the jet channel.

KEYWORDS:

• Supersonic jet
• laser transillumination
• wavefront distortions
• air density
• reconstruction

Acknowledgements

The authors are grateful to the colleagues of the ITAM SB RAS: Dr. V.I. Zapryagaev, Dr. N.P. Kiselev, and V.V. Bashurov for their help in organizing the experiment.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Ministry of Science and Higher Education of the Russian Federation (V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Sciences).