A Study on Effectiveness of Muffler on a Two Wheeler Noise

Abstract

The major contribution of the traffic noise, towards overall noise pollution, is a well-known established fact. Traffic noise from highways creates problems for surrounding areas, especially when there are high traffic volumes and high speeds. Noise pollution has hazardous effects on human health like Effects in work efficiency, loss of hearing ability. It may cause headache and psychological strain. Generally today’s main source of noise is traffic noise, out of which 70% is due to traffic noise. In order to minimize the noise it is necessary to study two-wheeler noise. In two-wheeler noise the main source of noise is exhaust noise. To reduce exhaust noise different types of mufflers are used. In this study Royal Enfield Bullet motorcycle (350 cc) was used to measure the noise of two-wheeler. In this different types of mufflers were studied out of which two were reflective type (M1 and M2), one was free flow (M3) and one was hybrid type (M4). This M4 type muffler was prepared by using technique of reflective type and absorptive type muffler a new hybrid type muffler M4 is modified from their existing design by introducing 1 cm thick glass wool because of its absorptive nature and it also controls the external heat that takes place on the outer surface of the muffler. Sound power, frequency spectra, sound pressure level and insertion loss are measured without and with different types of mufflers. It is found that due to this hybrid modification there is 2 dB (approx.) noise level reduced in the vehicle.