Prime Photonics has been working with Virginia Tech (VT) since 2017 to develop a filtered Rayleigh scattering system for multi-property flow measurement (MPFM; velocity vector, temperature, and density). We validated the MPFM system at Virginia Tech on a JT15D gas turbine engine inlet and recently performed validation testing at the Air Force Compressor Aero Research Laboratory (CARL). Thus far, our efforts have focused on the characterization of complex high-swirl bulk flows, and the MPFM system has not been specifically tuned or utilized for boundary layer characterization.
In Phase I, Prime and VT will implement the methods described in this proposal to demonstrate the capability of a new derivative of the MPFM system, our fiber-optic boundary layer profile (FOBLP) measurement system, to measure boundary layer velocity profiles without seeded particles. Analytical design followed by an experimental proof-of-concept measurement in a VT wind tunnel will be completed and key capability metrics will be characterized. Finally, a conceptual design for the proposed system will be completed for a NASA selected facility.
In Phase II, the conceptual FOBLP system design will be progressed through a critical design stage and fabricated, installed, and validated at a NASA facility. Further data acquisition and post-processing software improvements will also be made to improve usability and increase data analysis speed.
The first product planned for the FOBLP technology will be a Test & Evaluation (T&E) system for wind tunnel model applications. It will be marketed to wind tunnel operators, engine OEMs, airframers, NASA facilities, DoD personnel, and universities.
Other applications beyond boundary layer profiling on flightcraft and in wind tunnels are likely. Due to the very compact size of the fiber-based approach, and the ability to measure velocity, density, and temperature, applications could include interrogating difficult regions of interest in medical diagnostics, internal combustion engine diagnostics, and thermal systems.