The Engineer – UK team visualizes jet engine emissions in world’s first
A UK-based industrial and academic consortium has developed a new imaging technique to map CO2 emissions from a jet engine in real time.
Billed as a world first, the project brought together four different instrumentation research groups from across the UK, building on knowledge of gas species measurement in harsh environments, chemical species tomography and the development optical sources. Working with industry partners such as Rolls-Royce and Siemens, the team developed a 7m diameter optical mounting frame located just 3m from the exit nozzle of a Rolls-Royce gas engine turbine Trent. The platform was installed at the Instituto Nacional de Tecnica Aeroespacial (INTA) in Madrid.
From the frame, 126 beams of near-infrared laser light passed through the gas at various angles, but without disturbing the gas flow. The resulting images captured real-time CO2 emissions from the engine. It is hoped that the imaging technique can now be used to improve turbine design and develop greener aviation fuels and technologies. The study is Posted in Applied optics.
“This approach, which we call chemical species tomography, provides real-time, spatially resolved information on carbon dioxide emissions from a large-scale commercial engine,” said research team leader Michael Lengden. from the University of Strathclyde. “This information was not previously available on this industrial scale and is a vast improvement over the current industry standard emissions measurement, which involves feeding gases from the exhaust to a gas analysis system. located in a different place.
“The aviation industry is a major contributor to global carbon dioxide emissions, so there is a need for radical improvements in turbine and fuel technologies. By providing fully validated emissions measurements, our new method could help the industry to develop new technology that reduces the environmental impact of aviation.
For testing, the researchers recorded data at frame rates of 1.25 Hz and 0.3125 Hz while the motor was running through the full thrust range. Imagery showed that at all thrust levels, an annular structure with a high concentration of carbon dioxide was present in the central region of the engine. There was also a raised area in the middle of the plume, probably due to the shape of the engine.
“The very refined measurement methodology we used required a deep understanding of carbon dioxide spectroscopy and electronic systems that provide very precise data,” Lengden said. “In addition, a very sophisticated mathematical method had to be developed to calculate the image of each chemical species from the measured absorptions of the 126 different beams that we used.”
The project team included the universities of Strathclyde, Edinburgh, Manchester, Southampton, Loughborough and Sheffield; Rolls Royce ; Siemens; laser instrument manufacturer OptoSci Ltd. ; and imaging system makers M Squared Lasers and Tracerco.