Hybrid Finite Element Analysis for Rotorcraft Interior Noise Simulations, Phase II

Structural-acoustic concerns are present in rotorcraft, aircraft, launch vehicles, and crew modules since they are directly related with occupant comfort and noise induced vibration on payloads and electronic equipment. In all of these areas simulations are utilized during design. Currently, structural-borne paths are difficult to address, since the excitation propagates through the stiff load bearing members to the flexible panels and capturing the behavior of both within the same simulation model is challenging. The proposed Hybrid FEA innovation will allow including structure-borne noise simulations within a multidisciplinary design environment and it will enable the evaluation of advanced concepts and reaching cost and weight savings. Therefore, the proposed developments will be useful to all NASA groups and contractors interested in reducing weight and cost when designing rotorcraft, aircraft, launch vehicles, and crew modules. Structure-borne interior noise or radiated noise concerns are present in Naval applications where mechanical excitation from the propulsors is transmitted through stiff foundations to the outer hull of a vehicle; in automotive applications structure-borne noise comprises a major issue due to excitation applied at the shock towers from the suspension system, or due to excitation applied at the engine mounts of the vehicle's subframe from an operating engine; in heavy construction equipment excitation from the engine and the hydraulic system is transmitted through the load bearing structure to the interior cabin. In all of these areas simulations are utilized during design. Therefore enabling structure-borne noise computations and linking them with other simulation models within a multidisciplinary environment will offer cost and weight savings. Thus, there is a great commercial market potential for the outcome of this SBIR. More »