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This paper describes some applications of NASEFA to noise prediction of various automobiles, in addition to the concept and capabilities of the software. Energy Flow Analysis (EFA) have been developed to supply better analysis solutions than conventional method in medium-to-high frequency ranges, and Energy Flow Boundary Element Method (EFBEM) is recognized as a promising numerical method in applying EFA to complex system structures. Based on EFBEM, a reliable noise prediction software, NASEFAC++ has been developed to cover the multi-domain acoustic analysis problems shown in the diverse acoustic fields and to predict noise analysis in structure and noise distribution around structure happened from noise in structure. It has been also applied to the car interior multi-domain noise analysis and exterior noise problems around car showing reliable results.

In this paper, Power Flow Boundary Element Method (PFBEM) is studied as a new tool of the noise and vibration analysis in medium-to-high frequency ranges, and the noise and vibration prediction software using this method is developed. The developed prediction system includes both direct and indirect approaches, and also offers the various functions like baffled condition, absorption boundary condition and so forth. To verify the accuracy, the developed prediction system is applied to the prediction of the vibration energy distributions in simple beams and thin plates, and the results are compared with the exact solutions of Power Flow Analysis (PFA). As practical examples, car cabins surrounded by the materials of different absorption coefficients are modeled and the distributions of smoothed acoustical energy density are successfully predicted.

The Power Flow Finite Element Method (PFFEM) offers very promising results in predicting the vibration responses of system structures. We have developed the PFFEM based software for the vibration analysis in medium-to-high frequency ranges. The software can analyze the system structures composed of beam, plate, shell, link and other. components developed, and has many useful functions. In homogeneous domain, the software solves the energy governing differential equations for multi-DOF structural elements. At the discontinuities, it generates joint elements to cover the vibrational attenuation and can solve the joint element equations by using the wave transmission approach very efficiently. For the application of real vehicle system, an automobile is examined with respect to several parameters.

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).

The Energy Flow Analysis (EFA) offers very promising results in predicting the noise and vibration responses of system structures in medium-to-high frequency ranges. We have developed the Energy Flow Finite Element Method (EFFEM) based software, EFADS C++ R4, for the vibration analysis. The software can analyze the built-up structures composed of beam, plate, spring-damper, rigid body elements and so on, and has many useful functions. For the effectiveness and convenience of software, the main functions of the whole software are modularized into translator, model-converter, and solver. The translator module makes it possible to use of finite element (FE) model for the vibration analysis at low frequencies. The model-converter module changes FE model into energy flow finite element (EFFE) model.