Acoustic characterization of a partially-premixed gas turbine model combustor: Syngas and hydrocarbon fuel comparisons

Investigation of Dimethyl Ether Combustion Instabilities in a Partially - Premixed Gas Turbine Model Combustor Using High-Speed Laser Diagnostics

“…This paper focuses on a dual-swirl burner that undergoes a natural combustion instability at a frequency in the range between 250 to 480 Hz. The naturally occurring combustion instability has previously been shown to be the product a Helmholtz and a convective-acoustic mechanism which also displays a flame speed dependence 4 . This instability introduces oscillations in fuel and air mass flow rates which affects mixing, stabilization, instability strength, flame shape, and anchoring.…”

“…This instability introduces oscillations in fuel and air mass flow rates which affects mixing, stabilization, instability strength, flame shape, and anchoring. These combustion parameters have been investigated by studying the interaction between the flame and fuel-air mixing for varying fueling conditions in methane, propane, ethylene, and syngas flames 4 . This current work focuses on identifying similar interactions in dimethyl ether flames with the addition of high-speed laser diagnostics to evaluate flame surface density measurements and preheat zone marking.…”

Thermoacoustic combustion instability of propane‐oxy‐combustion with CO2dilution: Experimental analysis

“…They reported that transient flame topology change (periodic change between V-shaped to M-shaped structure) results due to increase in wall temperature as combustor power increases before eventual attainment of the wall equilibrium temperature corresponding to that power input. 41 In other words, irrespective of the fuel, it is the interaction between the flame and the acoustics that leads to such instabilities. 28 Thermoacoustic instability has been extensively studied in air-oxidized, premixed combustion systems 16,28-31 as reviewed by Lieuwen.…”

“…40 A comprehensive review of the differences in dynamic response characteristics to forced excitation between premixed and non-premixed flames is conducted by Magina et al 17 While there is no such thing as a "stable fuel," combustion of hydrocarbon fuels is reported to exhibit different stability characteristics compared with other fuels like hydrogen-enriched hydrocarbons or syngas. 41 In other words, irrespective of the fuel, it is the interaction between the flame and the acoustics that leads to such instabilities. Nevertheless, a high concentration of hydrogen in fuel mixture is shown to drastically affect, in a positive manner, the flame anchoring, as well as, shaping the flame into an elongated V-shape that dampens acoustics strength.…”

“…Nevertheless, a high concentration of hydrogen in fuel mixture is shown to drastically affect, in a positive manner, the flame anchoring, as well as, shaping the flame into an elongated V-shape that dampens acoustics strength. Allison et al 41 reported lower acoustic amplitude from a V-shaped, anchored, non-resonating flame for hydrogen-rich syngas fuel in contrast to a flatshaped flame produced by some hydrocarbon fuels. Narrower region for amplification or damping of combustion instability, accompanied by high heat-release density, is, however, reported for hydrogen-rich flames.…”