Description: Advances in computational capabilities for modeling the performance of advanced flight vehicles depend on verification measurements made in ground-based wind tunnels. As part of this process, the wind tunnels themselves must be well-calibrated and characterized. In particular to this project, the density, pressure and multi-component velocity of the air flow are of key interest. Southwest Sciences, in collaboration with the Southwest Research Institute, proposes to develop a novel, non-intrusive, laser-based measurement system for characterizing and calibrating the flow conditions upstream and downstream of test articles in wind tunnels. It uses inexpensive visible diode lasers and could be configured to match the needs of any particular type of wind tunnel, ranging from subsonic to hypersonic. The Phase I research will concentrate on developing and demonstrating the basic methodology of the system over a modest range of conditions. In Phase II we would expand the operation to the full range of expected conditions and verify the performance of the system in NASA-provided wind tunnels.

Benefits: This work would develop a versatile diode laser-based system for monitoring the flow conditions in wind tunnels of all sizes and velocities, with only minor changes to accommodate each specific configuration. In particular to the 3D velocity measurements, our approach could be adapted to characterizing combustion flows in turbines and hypersonic engines as well.

Besides NASA, potential customers include various military labs where aeronautical research uses wind tunnels, as well as aerospace contractors and universities, where wind tunnels are used for product development and research. This technology could possible be used for velocity measurements in combustion flows and eddy flux correlation measurements, providing a much wider group of customers.