The Measurement And Analysis Of The Thermal Parameters Of The Premixed Flame Under The Influence Of Acoustic Wave

The acoustically excited flame has been a main topic in the pulse combustion research. The dynamic measurement of time-resolved temperature and pressure fluctuations in combustion zone is the emphasis and difficulty of pulse combustion.In this research, we experimentally investigated the character of pulse flame excited by large amplitude acoustic field and analyzed the thermal parameters. The mean work and results of this dissertation are as follows:1) A theoretical basis for the application of a two-thermocouple probe, comprised of two fine-wire thermocouples of different diameters, to carry out fluctuating temperature measurements is established with the aid of the method of least squares.2) The amplitude distribution of standing wave measured in Rijke tube does no fully conform the half sine wave distribution. The antinodes of the standing wave move to the heat source. The first order and second order harmonic amplitude have been separated, and the full wavelength sinusoidal distribution model of the second order harmonic was obatained.3) The experimental results show that for the open environment and Rijke tube, the methane steady flames exist natural pulsation frequencies, one is 10.99Hz, the other is 49.81Hz.4) It was found that the acoustic mode enhanced the mixing of fuel and oxygen, reduced the flame length, and increased the flame envelope fold. Flames predominantly controlled by diffusion process were more susceptible to changes in their gas emissions than the premixed ones.5) The dynamic temperature sequence showed there were no main frequency but a number of large amplitude low-frequency of temperature fluctuation with the onset of acoustic oscillations. The incentive effect of sound field was that the flame average temperature distribution becomed more uniform, the original high temperatures decreased and low ones increased.6) The use of spectrum analysis and heating rate of the temperature fluctuation would promote the research of pulse combustion research because of the significance information.