拍音型駐波與雙聲源肯特管的印證 Dual-Source Kundt's Tube Interferometry and Beat-Pattern Analysis
When two sound waves with the same amplitude and very close frequencies interfere while traveling in opposite directions, they form a composite wave that exhibits the dual characteristics of both standing waves and beats. We call this a "beat-type standing wave." We used trigonometric sum-to-product identities to analyze its mathematical properties, predict its behavior, and simulate the composite waveform using a program. To observe the sound waves, we first studied a standard Kundt's tube, referencing literature to understand the behavior of the styrofoam balls. Finally, we expanded this into a dual-source Kundt's tube, using MATLAB to write a dual-channel sound wave program. This allowed for precise control over the volume, frequency, and phase of the two sources, achieving a frequency difference as small as 0.01Hz. We successfully verified the properties of the beat type standing wave and discovered that it can effectively push particles within the medium, indicating potential value for engineering applications.