Task 4.1 In-situ monitoring of combustion systems with longitudinal thermoacoustic modes
This task will build on the very successful work by Rouwenhorst et al (2016), where a robust online-monitoring technique was developed for thermoacoustic eigenmodes in an annular combustion system. This method will be adapted to longitudinal combustion systems. Output-only system identification will be developed to retrieve the decay rates of potentially unstable thermoacoustic modes; these decay rates serve as a measure of how close a mode is to becoming unstable. Experimental work will be performed on the in-house IfTA combustion test rig (40kW, partially premixed, longitudinal instabilities for certain operating conditions). In a further step, the method will be applied to industrial-size combustors with longitudinal eigenmodes, such as can-combustors used widely in gas turbines.