In the present problem, we have studied mechanical & aero dynamic induced noise. Mechanical noise refers to noise generated by the vibrating surface of the engine structure, engine components and engine accessories after excitation by reciprocating or rotary components. Aero dynamic noises are due to air intake and exhaust of the gases. In the present study, the identification of the engine sources such as Engine Structural Noise, Fuel Pump Noise, Oil Pan Noise, Air Suction Noise and Exhaust Noise has been performed.
These four noise sources like Fuel pump, oil pan, Suction noise and Exhaust noise were isolated through wooden/plastic/steel ducts by acoustical duct method for a 80.85 kW diesel engine coupled with a hydraulic dynamo meter at different speeds and load conditions. The results were compared with the overall/structural Sound Pressure Level (SPL). The SPL of engine sources like oil Pan, fuel pump & Air intake are also plotted to show the ranking of all sources and also checked the impact of speed and load on noise ranking of the components/systems of the engine.