Keeping cool enhances judgement Evaluating exhaust gases during combustor development typically relies on measurement systems placed downstream of the engine. A novel design concept avoids that harsh environment and promises to enhance reliability of test components and results. Climate Change and Environment © Thinkstock Annular shaped combustor concepts are often employed in new aircraft designs, including those of helicopters. An increasingly important component of quality assurance involves testing the combustor's exhaust gases. Ensuring acceptable pollutant concentrations, velocity, temperature and pressure requires a test bed whose measurement system does not add uncertainty to the measurements. Conventional test systems are placed downstream of the combustor, subjecting components to extreme environmental conditions, including temperatures over 2 000 degrees Fahrenheit. Such high temperatures can affect sensor function. Scientists developed an alternative, elegant in its simplicity, placing the measurement system upstream of the combustor, with EU support of the project NURMSYS. The system consists of the mechanical module and the acquisition rack, together with tailor-made Labview controlling software, which also collects data. Successful application of the innovative rotating measurement system relied on the use of rotary seals, sealing applications for high-speed rotation situations. In this case, the rotary seals facilitate circulation of both gases and cooling water as well as enable acquisition of independent gas samples. NURMSYS' system improves the ability of combustor manufacturers to assess exhaust gases during development testing. Commercial application is expected to speed development of eco-friendly combustors, benefiting EU manufacturers and the environment. Keywords Exhaust gases, combustor, measurement system, annular, upstream, rotary seals, cooling water, eco-friendly combustors
