Funded by NASA Langley Research Center

Energy Finite Element Analysis (EFEA) Development

In many situations, aerospace structures are subjected to high frequency excitations. Presently, noise performances of these products are determined either experimentally, which is not feasible at the early design stage, or by using computational simulation technique based on Statistical Energy Analysis (SEA). SEA requires a high level of analyst expertise and, in some instances, testing of the product’s components. An alternative computational simulation technique for high frequency vibration and noise prediction based on EFEA conceptually offers unique features such as the ability to input local power and damping treatments. More importantly, EFEA is based on the extensively used and comprehensively developed finite element method. The use of finite element method for both low and high frequency noise and vibration problems will provide the users a unified framework for the resolution of problems where the frequency spans a wide range.

 

Funded by NASA Glenn Research Center

Research

Currently, turbomachinery noise is often predicted using semi-empirically derived correlations and scaling procedures, many of which are extremely elaborate and incorporate a great number of aerodynamic, aeromechanical, and geometric parameters. Various numerical techniques for predicting turbomachinery noise have also been developed in recent years. There are many advantages for performing sound field modeling by numerical methods, e.g., saving on time and cost, ease of dealing with design changes, etc. However, all these techniques require knowledge of the sound sources. The identification of these sound sources is especially difficult in the presence of many potential sources that interact, which is exactly the case with turbomachinery noise. Acoustical holography allows the identification of complex noise sources that are otherwise difficult to characterize. The proposed development based on acoustical holography will enable identification of turbomachinery noise sources in aerospace industry as well as automotive and consumer products.

 

Noise Source Identification of Turbomachinery Noise Sources

Comet

Technology

Corporation