Prediction and Control of Motorcycle Engine Noise under Combustion LoadN. Bhatia , U. Mohite ,
 Mahindra 2 Wheelers, Pune, India
Engine is a major source of noise in motorcycle. Acoustic analysis of a single cylinder motorcycle engine under combustion load is presented. Engine surface acceleration obtained from vibration analysis is used as input for acoustic analysis. Process automation is carried out using java script to interpolate nodal acceleration data on the engine skin and to solve the acoustic model for each frequency step. Far field SPL is calculated for each frequency at 0.5m distance from engine. Results of acoustic analysis helped to identify critical frequencies with high SPL and areas of engine structure responsible for high noise radiation. SPL vs. Frequency plot and sound intensity plots from acoustic analysis are compared with test results. Structural modifications in engine are then implemented to achieve noise reduction.