Aerodynamic Analysis of Deployed Bay Doors on Modern High-Speed Aircraft

ABSTRACT: This SBIR program seeks to more accurately evaluate the unsteady aerodynamics on the weapons bay door due to the weapons bay, transient surface motions, and fluid-structure interaction. The goal of the program is to develop a methodology that will allow the unsteady aerodynamic loads on deployed aircraft bay doors to be evaluated early in the design process such that designs can be optimized to avoid aeroelastic instabilities or fatigue induced failures. The program will leverage methods previously developed by ATA that facilitate fully-coupled, unsteady fluid-structure interaction simulation of flexible structures exposed to subsonic, supersonic, and hypersonic flows. The program will take a building block approach to gradually add complexity to the simulation of the deployed bay door, beginning with rigid CFD analyses at selected flight conditions and advancing to static and then dynamic fully-coupled FSI analysis by the end of Phase I. The methodology will be validated using flight test data and will lay the foundation for development of a unified capability in Phase II that can analyze a analyze a dynamic store separation with a fully flexible door undergoing cycling and predict sonic fatigue, buffet, limit cycle oscillation, and flutter. BENEFIT: The methods and tools that will be developed under this SBIR can directly impact the design of a variety of geometrically complex hardware that is deployed into, or otherwise exposed to, high speed, turbulent flow over a range of flight conditions and must be capable of surviving the harsh unsteady loads that result from that environment. This includes design optimization of weapons bay doors, landing gear doors, external fuel pods, attachment hardware for wing and fuselage weapons, control surfaces for supersonic and hypersonic vehicles, etc. The methods will allow engineers to accurately predict the dynamic response of these structures under the unsteady fluid dynamic loads and design them so as to avoid sonic fatigue, buffet, limit cycle oscillation, and flutter. The methods can also be applied to more general applications that benefit other industries. These industries may include the commercial aerospace, space, maritime, and automotive industries where the tools can be used, for example, to create optimal designs for any surfaces and/or cavities exposed to high-speed fluid flows.