Development of the Acoustic EFA(Energy Flow Analysis) Software NASEFAc++R1 and its Applications to Automobiles 2005-01-2346

Energy Flow Boundary Element Method (EFBEM) is developed as a promising tool of the noise analysis of system structures in medium-to-high frequency ranges. EFBEM is numerical method which solves the energy governing equation using boundary element technique for the noise prediction of complex structures where the exact solution is not available. Based on EFBEM, a noise prediction software named ‘NASEFA(Noise Analysis System by Energy Flow Analysis)’ has been developed. NASEFA consists of three major parts, i.e., translator, model converter and solver module. The translator makes NASEFA BE-model from bulk data framed by the preprocessor of a commercial FEM software, and the model convertor changes BE-model to EFBE-model including the various data such as structural materials, medium properties, sources and boundary conditions (acoustic energy density, intensity and absorption rate). NASEFA solves the acoustic energy density and intensity on boundary and in field, and moreover, it analyzes the interior/exterior noise problems for single and multiple domains in two- and three-dimension. This paper describes some applications of NASEFA to noise prediction of various automobiles, in addition to the concept and capabilities of the software.