Pratt & Whitney and Virginia Tech have announced a brand-new technology, which will use lasers to accurately measure important gas turbine engine factors such as velocity, temperature, and density. This technology, which is pending a patent, is known as Filtered Rayleigh Scattering for Thrust measurement, or FRST.
FRST makes use of the fact that light scattering from air molecules above a laser-illuminated area, will provide information about the gas flow field. A laser beam is shone across the turbine’s gas path and a high-quality camera keeps track of the scattering light. This recording is then filtered to eliminate signal corruptions.
"The ability to use lasers and optical sensors represents a major step forward in engine instrumentation technology," said Geoff Hunt, senior vice president of engineering and technology at Pratt & Whitney.
There are hopes that this technology can be used to measure CO2 emissions, so that the environmental impact of flight may be properly understood. "We expect the technology will have other applications in the development and certification of aircraft engines," said Todd Lowe, Professor of Aerospace Engineering at Virginia Tech.
FRST successfully measured the thrust of a research engine at Virginia Tech, with results very similar to traditional measuring tools such as probes and sensors. The two teams hope to flight test this technology soon.