Abstract:
A strong thermoacoustic oscillation of a surface burner made of a perforated metal fiber plate on the exit of a tube was investigated. First, the thermoacoustic power generation by a plane heater was analyzed theoretically based on the one-dimensional analysis of the heat transfer response of the heater to the oscillating flow and the result showed that the maximum power generates when the gas velocity is around ((omega)(alpha))[sup 1/2], where (omega) is the angular frequency and (alpha) is the thermal diffusivity of the gas. Second, an experiment was performed for the frequency characteristics and the standing wave pattern in the tube for various fuel rates and air ratios. It was found that the modal frequency of the tube associated with the maximum power generation is driven by the heater and that the effect of turbulence lowers the frequency by increasing the effective thermal diffusivity. In addition, the measured impedance of the perforated plate on the exit of a tube showed that the thermoacoustic oscillation can occur although the heat source is not at the lower half of a tube corresponding to the condition for the Rijke thermoacoustic oscillation.