Design Optimization and Analysis of Advanced Exhaust Systems Navy STTR FY2014.A Sol No.: Navy STTR FY2014.A Topic No.: N14A-T005 Topic Title: Design Optimization and Analysis of Advanced Exhaust Systems Proposal No.: N14A-005-0012 Firm: Combustion Research and Flow Technology, Inc. 6210 Kellers Church Road Pipersville, Pennsylvania 18947-1020 Contact: Neeraj Sinha Phone: (215) 766-1520 Web Site: www.craft-tech.com Abstract: Historically, aircraft engines have featured relatively simple axisymmetric exhaust shapes with several moving parts; however, future engine exhaust systems are expected feature compact, sinuous ducts with complex non-axisymmetric shapes, fixed exit areas, thrust vectoring etc., constructed with a minimum number of moving parts. Their exhaust plumes are currently not well understood; however, LES analysis of the exhaust system interior aerodynamics and the plume appears promising. Attention must also be directed towards the structural analysis. The current practice in the aerospace industry is to conduct uncoupled aerodynamic and structural analyses, which is a cumbersome, time consuming and expensive. It results less than optimal final exhaust configurations under tight time and budget constraints. This provides a strong motivation for creating a multi-disciplinary exhaust system optimization environment within which LES modeling of the exhaust flowfield is coupled to structural analyses of the components forming the exhaust system with the objective of minimizing structural component weight and maximizing system performance. Such tools are requisite for supporting the development of next-generation engines and optimizing their designs with regards to maximum system performance, as well as durability from the improved understanding of the structural loads on the exhaust nozzle and duct components leading to weight reduction. Benefits: The proposed program is of direct relevance to the U.S Navy and its prime contractors responsible for the development of advanced high performance military gas turbine engines. The successful development of a high fidelity nozzle design optimization capability will significantly shorten the engine development cycle by enabling robust and accurate evaluation of designs that enhance thrust performance and durability. Details of the dynamic response of nozzle structures to this loading can be incorporated into the design process at an early stage and thus help in the design of "durable" structures. Also threat assessment studies of IR/RCS signature or noise emissions levels can be easily evaluated using the proposed modeling. This will be particularly appealing to the U.S Navy and engine OEMs as it can facilitate a "quick" scoping out of the design modifications without full-scale, prototype implementation. This would result in significant cost savings to the U.S Government. The STTR technology will find application at the US Navy and its prime contractors as a test bed for conducting design support. This modeling is equally relevant to next-generation engines with their focus on enhanced fuel economy and low noise emissions. Return