Large-amplitude standing-wave fields in standing-wave tube with abrupt cross section

Abstract

The transfer matrix is used to analyze the properties of a two-step standing-wave tube with abrupt cross-section (STAS). With the STAS, a large-amplitude standing-wave field of 184.7 dB is established at the right end in an improved standing-wave tube experimental system under the excitation at the resonant frequency of the 1st-order peak. Harmonic development at the right and left ends are investigated experimentally for the large-amplitude standing-wave fields obtained under the excitations at the resonant frequencies of the 1st- to 5th-order peak. For comparison, the large-amplitude standing-wave fields excited at the resonant frequencies of the 1st- to 5th-order trough are also studied experimentally in the same way and the large-amplitude standing-wave field of 179.1 dB is obtained at the resonant frequency of the 1st-order trough. For further comparison, the variations of sound pressure level (SPL) and waveform distortion of the fundamental waves at the right and left ends under the excitations at the resonance frequencies of the 1st- to 5th-order peak and trough are also investigated experimentally. Under the same source-driving voltage, the SPL of the fundamental wave at the right end excited at the resonance frequency of the 1st-order peak are higher than the corresponding one at the resonance frequency of the 1st-order trough while forthe waveform distortions, theinverseistrue.