#thermoacoustic instability

[fuckyeahfluiddynamics]

Searching for Stability in Cleaner Flames

Spiking natural gas power plants with hydrogen could help them burn cleaner as we transition away from carbon power. But burners in power plants and jet engines can be extremely finicky, thanks to thermoacoustic instabilities.  (Image and research credit: B. Ahn et al.; via APS Physics) Read the full article

[materialsscienceandengineering]

Putting gas under pressure

Understanding gas flames' response to acoustic perturbations at high pressure should make next-generation turbines safer and more efficient.

Soldiers marching lockstep across a bridge can cause the structure to collapse if the rhythm of their step matches the bridge's natural vibration frequency. Combustion engineers must consider a similar effect when designing the gas turbines used in electricity generation and aero-engines.

Just as soldiers' feet can cause bridge sway to reach the point of destruction, a gas turbine can be damaged, or even explode, if heat and pressure fluctuations produced by the flame couple with the acoustics of the combustion chamber. At a lesser degree, this'thermoacoustic instability hampers efficient combustion, increasing noise and pollution emissions.

Predicting and preventing thermoacoustic instabilities remains challenging for the design of a gas turbine. To improve the models used, Deanna Lacoste from KAUST's Clean Combustion Research Center and her colleagues have measured the stability of gas flames at elevated pressure.

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