Design and analysis of Helmholtz resonator that reduces noise and harvests energy with piezoelectric effect

Research into energy harvesting has recently received a lot of interest. These research are critical for transforming waste energy into usable energy. Acoustic energy is a type of energy that has the potential to be recycled. Sound waves can be produced by a variety of noise sources, wasting energy in practically every part of our daily life. By harvesting acoustic energy from these discarded sound waves, it is possible to meet the energy requirements of low-power devices. Furthermore, this eco-friendly approach has the potential to replace the batteries in microelectromechanical systems (MEMS) devices. This thesis describes a mechanism for harvesting energy utilizing the piezoelectric effect and sound pressure. To boost the system's energy output, 15 distinct Helmholtz resonators were built. When subjected to acoustic pressure, Helmholtz resonators have the ability to increase the energy gained through the vibrational amplifying effect in resonance cavities. These resonators also have damping effects, thus they are being studied for noise reduction in a variety of sectors. This thesis investigates the impact of Helmholtz resonators on both acoustic energy harvesting and noise reduction. In the context of this information, the goal of this thesis is to investigate the effects of noise reduction and acoustic energy harvesting on 15 Helmholtz resonators arranged based on various cone inlet diameters, neck lengths and neck diameters at different frequencies, and to offer suggestions for improvement. The Helmholtz resonators utilized in the experiment were made with 3D printing technology. The resonators were produced of polylactic acid (PLA) material using a 3D printer due to its ease of manufacture, low cost, and availability from natural sources. The Helmholtz resonators and piezoelectric discs were secured with aluminum plates measuring 60x60x0.4 mm. The experiments had four stages. The first of these is the sound pressure measurement experiment of the speaker device used as a force. In this experiment, sound pressures in the specified frequency range were measured and sound pressure levels were obtained. In the second stage, the frequency-acceleration values in the resonators and on the plate were measured under acoustic pressure. While sound waves had a direct impact on the prototype, laser vibrometry was utilized to quantify frequency acceleration on the Helmholtz resonators and plate by focussing the laser. The third stage involved acoustic energy collection. Piezoelectric discs and resonators rigidly mounted to the plate were subjected to sound pressure from a speaker. The sound pressures created vibrations on the piezoelectric disk in the resonator cavity. The piezoelectric disc transformed the vibration-induced deformation energy into electrical energy, and an oscilloscope was used to obtain voltage-time graphs. During this experiment, sound pressure measurements were made with a microphone placed near the prototypes and frequency-sound pressure level graphs were generated. The gathered data were utilized to investigate the noise-reduction effects of acoustic energy harvesting systems. The experiments revealed that Helmholtz resonators had a noise-reducing impact. For the first time in the literature, the resonator's effectiveness was tested throughout a large frequency range. The efficiency of the resonators varies with frequency. Comprehensive experimental investigations were used in this thesis to explain why this frequency-dependent efficacy exists. To improve the system, specialized research on the proper frequency ranges for each Helmholtz resonator are required. This long study demonstrated, via the application of numerous analysis methodologies, that the developed Helmholtz resonators can be employed in acoustic energy harvesting and noise reduction systems.