The majority of heavy-duty gas turbine engines use can-annular combustion systems. Each can (combustor) is connected by an annular transition piece, upstream of the first stage turbine nozzles. Due to the presence of this region between adjacent cans, two different low-frequency instabilities – push-push and push-pull modes – are excited in can-annular combustion systems. Therefore, the region is referred to as cross-talk area. For push-push modes, the flame dynamics of adjacent combustors are manifested by in-phase interactions, leading to the formation of a pressure antinode in the cross-talk area. For push-pull modes, on the other hand, acoustic oscillations in neighboring cans are completely out-of-phase, and as a result a pressure node is generated in the cross-talk area. Fundamental mechanisms of these multi-can combustion dynamics are currently unknown. Here we present experimental observations of thermoacoustic interactions between two adjacent model gas turbine combustors with cross-talk area. The development of push-push, push-pull, and bimodal dynamics is discussed in comparison with self-excited instability data obtained from an isolated tunable rig without cross-talk area, under the same operating conditions.
Kyutae Kim received a BE in Mechanical Engineering from Korea Aerospace University in 2004 and a MS in Aerospace Engineering from Korea Advanced Institute of Science and Technology (KAIST) in 2006. Subsequently, he received his PhD in Mechanical Engineering from Penn State in August 2009. Upon completion of his PhD, he accepted a Marie Curie Fellowship at the University of Cambridge in England, where he continued his work on combustion dynamics within the IAPP-STRATEGI network project sponsored by Cambridge, TU Darmstadt in Germany and Rolls-Royce. In August 2012, he joined GE Global Research Center in Niskayuna, New York, where he contributed to the development of GE’s advanced aircraft engines, including LEAP and GE9X. He relocated from GE GRC to GE Power in Greenville, South Carolina in February 2015, where he contributed to high-pressure single can combustion tests and 1D/3D thermoacoustic modeling for the development of 6F.01 and 9HA.01 heavy-duty gas turbine engines.