Study on Band Gap and Sound Insulation Characteristics of an Adjustable Helmholtz Resonator

To solve the problem of low-frequency noise in environment, a Helmholtz-type phononic crystal with adjustable cavity structure and labyrinth tubes was designed. The unique design tube greatly increases length tube, improving sound insulation performance, realizes active regulation band structure. gap characteristics were analyzed by finite element method (FEM) electro-mechanical-acoustic analogy method. result shows that, firstly, can generate two complete gaps range 0–500 Hz, there is lower limit 40 Hz. Meanwhile, has excellent performance Secondly, multiple resonant be connected adjusting structural layout through telescopic screw, so as to achieve purpose widening control environmental noise. Finally, periodic arrangement structure, reducing spacing between cells effectively increase bandwidth gaps. This broadens idea provides new control.