Experiments on thermoacoustic instabilities were conducted in premixedimpinging jet configuration for premixed syngas-air mixtures with the volume ratio of 10% and 90% for H2 and CO respectively, by varying
equivalence ratio Ф and global velocity gra...
Experiments on thermoacoustic instabilities were conducted in premixedimpinging jet configuration for premixed syngas-air mixtures with the volume ratio of 10% and 90% for H2 and CO respectively, by varying
equivalence ratio Ф and global velocity gradient C g. The main concerns are focused on clarifying the mechanisms for an oscillation generated in noisy flame and an instability driven via flame-vortex interaction. The result shows that the non-reacting flow field presented divergent flow shape, while the reacting flow field showed an “S”shape. The FFT frequencies of flame and vortex were acquired and analyzed to obtain the
frequency. The frequency of non-reacting flow vortex (V N·R·V=140 Hz) was different from natural frequency of burner itself (60 Hz). The frequencies of vortex and pressure perturbation were similar to flame frequency.
Thus, the oscillation was caused by flame not flow and the flame-vortex interaction was associated with self-excited instabilities as comparison of frequency, pressure perturbation and vortex.