FLEET System for Global Velocimetry at High Repetition Rates in Nitrogen-Based Hypersonic Ground Test Facilities.

ABSTRACT: The objective of the effort is the development of a Femtosecond Laser Electronic Excitation Tagging (FLEET) system and data analysis tools for the measurement of transport parameters in nitrogen and air ground test facilities without seeding the flow with either particles or with foreign gases.  The effort follows Phase I accomplishments, wherein a transportable FLEET laser system with similar attributes to the system proposed for the Phase II development was tested in a supersonic nitrogen facility at the Air Force Arnold Engineering Development Complex (AEDC) White Oak site in Maryland, and preliminary data analysis was conducted. The Phase II effort will focus on the development of FLEET systems for the acquisition of quantitative transport data in supersonic and hypersonic ground test facilities that are designed to be used for the testing of full scale or scalable aerodynamic platforms, engines and associated components. The Phase II work will include testing at the AEDC White Oak Tunnel 9 facility to determine the requirements for the final system, preferred optical configurations, and possible flow perturbations that may be introduced by FLEET. This will be followed by the development and delivery of a FLEET system to AEDC and the development of data processing capabilities.; BENEFIT: Commercial applications include the installation of similar systems at other Air Force Laboratories with aerodynamic and propulsion test facilities, at other national laboratories with testing requirements including NASA and the Navy, at University laboratories where studies of transport properties in air and nitrogen are of interest, and at commercial enterprises such as Boeing, Lockheed, ATK, etc. where vehicle and propulsion technologies are being developed. Applications in the automotive and fast train industries may also arise. With a reduction of the system weight and power requirements, flight applications become viable, and include the potential for air data systems for high speed platforms where conventional pressure based air data are no longer reliable.