Research Projects

The thermoacoustic characteristics of a 3D printed LPG or H2 fueled triple-swirl turbulent burner will be analyzed using optical diagnostics such as planar laser-induced fluorescence (PLIF), stereo particle image velocimetry (sPIV), and high-speed imaging. The proposed project will investigate the steady and unsteady combustion behavior of various LPG or H2 fuel blends to achieve a complete transition from LPG to H2. The complex triple-swirl burner section with co-rotating and counter-rotating swirl flow combinations and fuel or air injections will be entirely constructed using 3D metal printing. This would allow us to avoid flashbacks at lower bulk velocity operating conditions. A combustor section with optical access and quartz tube arrangements will be built to study the steady and unsteady combustion phenomena. Planar laser-induced fluorescence will be used to gather the scalar field of reacting flows for various operating conditions, essential for optimizing combustion efficiency and reducing emissions. In the proposed work, OH molecules will be excited using a 283 nm laser sheet, and the resulting fluorescence emission will be acquired to obtain information about the flame behavior. Particle image velocimetry will be employed to measure the velocity and turbulence of the fuel and airflow inside the combustor. This technique involves seeding the flow with small particles and capturing their motion with CCD cameras. The resulting images will be analyzed, and the flow patterns will be identified to know the regions of high turbulence that may contribute to thermoacoustic instability. High-speed imaging will be realized to capture the OH* chemiluminescence for understanding the flame dynamics and visualize the thermoacoustic oscillations of the burner with quartz tubes of varying lengths. The temporal signals of acoustic pressure will be measured using pressure transducers to identify the amplitude, frequency, and nonlinear features of LPG or H2 combustion behaviors at various mixture compositions and operating conditions. The data from pressure sensors and optical diagnostics will be analyzed using nonlinear dynamics and synchronization theory framework to understand the complex interactions better, driving regions, and to devise effective strategies for suppressing thermoacoustic oscillations.