Flow Visualization and Spectroscopy in Hypersonic Flows: A Review

This paper is based upon a session of the NATO Advanced Research Workshop, New Trends in Instrumentation for Hypersonic Research held at the ONERA La Fauga Facility in France during the week of April 27, 1992. The discussion includes some of the frontiers of the technology of flow visualization and spectroscopy as well as a discussion of the current development needs and trends. Included in the discussion are optical integrated measurements such as resonance absorption, schlieren, interferometry, and holographic methods. The discussion shows that while the technology is mature in a broad sense, a significant number of new development areas exist such as resonant holography and phase shifting holographic interferometry. The maturity of the technology makes it immediately applicable to many problems and the untapped potential offers considerable room for improvement of existing capability. The methods which are described can be used in harsh environments and have the potential for becoming flight test diagnostics for the measurement of temperature, density, constituency, and velocity.