NASA SBIR 2008 Solicitation


PROPOSAL NUMBER: 08-2 A2.09-9167
PROPOSAL TITLE: Hybrid Finite Element Analysis for Rotorcraft Interior Noise Simulations

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Michigan Engineering Services, LLC
2890 Carpenter Road, Suite 1900
Ann Arbor, MI 48108 - 1100
(734) 358-0792

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Geng Zhang
2890 Carpenter Road, Suite 1900
Ann Arbor, MI 48108 - 1100
(734) 477-5710

Expected Technology Readiness Level (TRL) upon completion of contract: 6

TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
One of the main attributes contributing to the competitiveness of rotorcraft, is the continuously increasing expectations for passenger comfort which is directly related with reduced vibration levels and reduced interior noise levels. Such expectations are amplified in the VIP market where people are used in the acoustic and vibration levels of civil and executive jets. One of the most critical excitations for interior noise in helicopters is the one from the gearbox. Thus, the structure-borne noise path (i.e. excitation propagating from mounting locations through the fuselage structure to the panels of the cabin and to the interior) must be captured in rotorcraft interior noise computations. This proposal addresses the need stated in the solicitation for developing physics based tools that can be used within a multi-disciplinary design-analysis-optimization for computing interior noise in rotorcraft applications. Currently, there is no robust simulation capability for this type of acoustic simulations. The hybrid FEA method can be used for structure-borne helicopter applications and can be integrated very easily (due to the finite element based model) with models from other disciplines within a multidisciplinary design environment. It combines conventional FEA with Energy Finite Element (EFEA) and it extends the frequency range of applicability of an existing finite element model by converting the elements that model the flexible panels into EFEA type of elements. A seamless Hybrid FEA capability of commercial quality will be developed based on MES' commercial EFEA code. UTRC will participate in the proposed effort for validating the new developments through comparisons to test data for a rotorcraft structure and for providing technical consultancy.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
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.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
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.

NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.

Aircraft Engines
Launch and Flight Vehicle
Structural Modeling and Tools

Form Generated on 08-03-09 13:26