In this seventh installment of a 14-part series of monthly articles, The Combustion Institute recognizes the 2017 Distinguished Papers selected from among the scientific papers presented during the 36th International Symposium on Combustion. Congratulations to N. Noiray and A. Denisov for winning the DPA in the Gas Turbine Combustion colloquium.

The authoritative paper, A method to identify thermoacoustic growth rates in combustion chambers from dynamic pressure time series, explores thermoacoustic instabilities in high performance combustion chambers at given targeted operated conditions. The scientific team’s research quantifies the strength of a thermoacoustic self-sustained oscillation, its linear growth rate, as mentioned in the title.

Practical combustors such as gas turbines, aero engines, or rocket engines are only equipped with a few pressure sensors to monitor the thermoacoustic instabilities and it is crucial to grasp as much information as possible from these signals. During the validation phase of a new machine, a system can operate beyond the normally acceptable acoustic level limits in order to identify problematic operating conditions. Up to now, the design of acoustic damping systems to suppress the instabilities at the best-performance operating conditions was relying on trial and error testing.

The immediate impact of the paper presents a new method to unveil and quantify the hidden parameters that govern the robustness of harmful thermoacoustic instabilities, and the ability to suppress those instabilities for lower emission rates and longer lifespans of combustion chambers. In the long-term, the scientific team’s research will enable reliable development of mitigation solutions to these instabilities. By quantifying the strength of the acoustic-flame interaction, which leads to damaging intense acoustic field, reliable passive or active control systems can be designed.

Beneficiaries of the research include combustor manufacturers, especially among the gas turbine, aero- and rocket engines industries. The scientific team’s fundamental research will also assist other scientists that seek to extract more information about their gas turbine systems.

The paper’s research was conducted at the CAPS Laboratory in the Department of Mechanical and Process Engineering of the ETH Zürich, Switzerland, and at the combustion laboratory of the Paul Scherrer Institute, Switzerland. The basis of the theoretical part of the paper was already available from one of Professor Noiray’s previous publications. New research for the paper began in the summer of 2015 and was completed by November, 2015.

About 1,300 papers were submitted to the 36th Symposium in 14 combustion science colloquia. Those papers were categorized by teams of colloquium coordinators and co-chairs, and then distributed to approximately 1,000 scientific reviewers. One paper in each discipline was awarded the recognition of Distinguished Paper.

The 14 Distinguished Papers undergo committee review for consideration to receive the Silver Combustion Medal that will be awarded during the 37th Symposium in Dublin, Ireland. A paper selected for this honor exemplifies quality, achievement, and significance to advance a field of combustion science. Distinguished papers are selected biennially from among the scientific papers presented during the International Symposium on Combustion and accepted for publication in the Proceedings of The Combustion Institute.