Study of Noise Generated by Kirloskar Single Cylinder Four Stroke C.I. Engine

Abstract

In our modern, rapidly expanding environment one of the developing problems is that of “Noise”. The purpose of this report is to the study the fundamentals of acoustics and analysis of engine noise which causes serious effects on human beings. In India, the transportation sector is growing rapidly and number of vehicles on Indian roads is increasing at very fast rate. This has lead to overcrowded roads and pollution. Noise from a diesel engine is caused by vibration of the surfaces of the structure. Combustion is a major force which generates pressure and the engine mechanism also generates forces, these forces combine and cause the structure to vibrate. So, it is necessary to study noise generated by the engine by measuring sound pressure level and calculating sound power and measure the vibrations in which acceleration, velocity and displacement are measured at specific point to understand under which frequency range the vibrations are high. The sound pressure level under 1-1 Octave band Frequency range is also studied. All these studies were done by varying compression ratio and load at all marked locations of the engine. In the analysis of C.I. Engine noise the maximum sound pressure level comes out at exhaust and the acoustic power increases as load increases for all compression ratios. In the analysis of vibration the acceleration and vibrations are analyzed in which the acceleration is maximum at 1000 Hz and vibration is maximum at 500 Hz. From the analysis, there is more need to concentrate on low frequencies. There is no direct correlation find between sound pressure level analysis and vibrational analysis for the marked location. The analysis for frequency spectrum is also done on engine to find out under which frequency the sound pressure level is high. The regression analysis was also carried out for all locations and for acoustic power to find out the percentage error between measured value and predicted value. This study will help to optimize compression ratio and load produces lesser or higher noise in which frequency range and at which point.