Abstract
Acoustic energy contained in sound pressure waves that propagate in the environment and come from various sources (eg operation of internal combustion engines, industrial processes, transport, etc.) is regarded as a waste pollutant. In very few cases this energy is recovered and converted into other forms of energy (electrical, thermodynamic, and so on). However In the past 10 years, the attention to this energy harvesting increased and began to be reported concrete by results obtained in laboratories.
Purpose of the research is to determine the amount of energy that can be harvested from flue gas system for internal combustion engines through a proper acoustic energy conversion. The conversion is based on the Helmholtz resonator and was conducted under laboratory conditions. Based on experimental measurements performed were determined noise levels associated to the operating speed range goal of a single cylinder engine and equipment also analyzed sound pressure waveform that characterizes the evolution of the exhaust gas.
After analyzing spectral and energy acoustic pressure waves recorded were identified characteristics corresponding exhaust noise test speed range.
Determined properly obtained were generated in the converter sampled acoustic signals on time. Experimental results have shown the efficiency of the proposed device (the principle Hemholtz resonator) to convert noise - waste energy) into low power electricity. Was also identified the engine speed ranges where the harvested energy has an acceptable efficiency.
Keywords: noise, acoustic, energy, conversion, electromagnetic transducer, Helmholtz