Discussion on resonant frequency in thermoacoustic systems

Publisher Summary This chapter presents a new method of calculating resonant frequency, referred to as standing wave minimal antinode method (SWMAM). This makes it possible to consider the influence of resistance, since zero antinode is no longer a necessity as in an ideal standing wave system. Numerical simulation will be made on three types of tubes for their resonant frequencies with three methods, focusing on the influences of impedance composition on the resonant frequency. The SWMAM is proved valid for calculating resonant frequency, after comparison with two traditional methods. It is convenient for analyzing the influence of impedance on the resonant frequency. The impedance of tube ends has obvious effect on resonant frequency when the resistance is not so large. When the end buffer volume is 0.5–3 times that of tube, the resistance fraction greatly affects the resonant frequency. Based on three different methods, numerical simulation has been made on three types of tubes for their resonant frequencies, focusing on the influences of impedance composition on the resonant frequency. Results under different conditions are used to discuss the equality and difference among these methods.