Outer sound field simulation of a diesel engine based on coupled BEM/FEM method

Sound field induced by structural vibration of a highly intensified V6 diesel engine was simulated with coupled boundary element method and finite element method (BEM/FEM) method. Acoustic parameters such as the whole engine's radiating acoustic power, radiation efficiency, contributions of main parts to acoustic results, near field and far field sound pressure level, as well as outer field sound intensity vectors were calculated. Under assistance of these results, structural acoustic optimization was conducted on of the diesel's structure, especially the lower crankcase. Results show that the modification could ameliorate the diesel engine's structural sound radiating condition in the studying frequency band.