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

ABSTRACT: Unsteady aerodynamic loading and flow separation on modern high speed aircraft weapons bay doors can excite aircraft structural modes and lead to buffet, flutter, or fatigue-induced failures. Rigorous numerical simulations, wind tunnel and flight tests are typically carried out to investigate the aerodynamic loading on the doors, but analyses often only consider steady loads on rigid doors and neglect transient and aeroelastic effects. Higher fidelity multidisciplinary analysis tools are critically needed to better understand and characterize the effects of unsteady loads and to design measures for mitigating buffet, flutter, and fatigue. This SBIR project will deliver breakthrough technologies to significantly improve predictive capabilities. Hybrid RANS/LES methods with low-dissipation schemes and tightly-coupled fluid-structure interaction will be used for weapons bay flow simulation including unsteady loading and structural response. The proposed research enables: (1) Improved fidelity and multidisciplinary analysis; (2) Greatly reduced numerical dissipation; and (3) Improved acoustics modeling for weapons bay tonal content. The merits of the proposed approach will be investigated and demonstrated in Phase I for benchmark weapons bay problems. Limited wind tunnel tests will be conducted for computational model validations. In Phase II, a comprehensive experimental program will be executed, and the simulation capabilities will be refined and validated against experimental data and realistic targeted applications. BENEFIT: The proposed computational and experimental effort will provide a much needed high-fidelity prediction tool for low-dissipation aerodynamics and fluid-structure interaction applications of high-speed aircraft over wide range of loading frequencies. This technology has immense potential in military and commercial aircraft sectors. Direct applications of this technology are in low-speed landing gear and speed brakes systems as well as high-speed weapons bay doors systems and for developing protocols for munitions delivery to achieve the desired impact. Other applications may include instrumentation cavities, control surfaces motion, and other moving parts. The proposed effort will have significant impact on improving reliability and safety procedures of weapons bay designs of tactical aircraft and will reduce dependence on flight and wind tunnel tests.