Abstract
Thermoacoustic phenomenon has attracted attention as one means of utilizing relatively low temperature waste heat from automobiles and factories. Thermoacoustic systems utilizing thermoacoustic spontaneous oscillation have applications including generators, engines, and refrigerators. The spontaneous oscillation pressure of the thermoacoustic system depends on the temperature variation of the heat source when the load connected to the system is constant, which yields a oscillation death and thus power generation shutdown due to a large pressure drop. Therefore, oscillation pressure amplitude needs to be maintained at a constant value by varying the system's load. In this paper, electricity-feedback traveling-wave thermoacoustic generator is considered as a target system of which pressure amplitude is to be maintained at a reference value by dynamically varying a load resistance in the electricity feedback circuit which is a replacement to the acoustic power feedback in the looped-tube-type thermoacostic systems. Experimental results show that it is possible to maintain the pressure amplitude at constant against temperature fluctuation by constant oscillation control of which PI(proportional and integral) controller's output is used as the reference command for the load resistance.
