Thermoacoustic oscillation in channels of the pressurized He II Original Research Article

In channels filled with the pressurized He II at 1 atm, a continuous thermoacoustic oscillation with a clear sound is triggered above the critical power-input qλ of the phase transition under some conditions. A temperature distribution along the channel length is entirely maintained as long as the thermoacoustic oscillation lasts, i.e. the heat qλ is kept transporting in the vortex state without drying the heater surface. The characteristic frequency of the thermoacoustic oscillation depends both on the channel length and weakly on the bath temperature, reflecting the property of the 1st sound.