High-Fidelity Aerostructural Design Optimization of Transport Aircraft with Continuous Morphing Trailing Edge Technology

[摘要] Adaptive morphing trailing edge technology offers the potential to decrease the fuelburn of transonic commercial transport aircraft by allowing wings to dynamicallyadjust to changing flight conditions. Current configurations allow flap and ailerondroop; however, this approach provides limited degrees of freedom and increaseddrag produced by gaps in the wing’s surface. Leading members in the aeronauticscommunity including NASA, AFRL, Boeing, and a number of academic institutionshave extensively researched morphing technology for its potential to improve aircraftefficiency.With modern computational tools it is possible to accurately and efficiently modelaircraft configurations in order to quantify the efficiency improvements offered by mor-phing technology. Coupled high-fidelity aerodynamic and structural solvers providethe capability to model and thoroughly understand the nuanced trade-offs involvedin aircraft design. This capability is important for a detailed study of the capabilitiesof morphing trailing edge technology. Gradient-based multidisciplinary design opti-mization provides the ability to efficiently traverse design spaces and optimize thetrade-offs associated with the design.This thesis presents a number of optimization studies comparing optimized config-urations with and without morphing trailing edge devices. The baseline configurationused throughout this work is the NASA Common Research Model. The first opti-mization comparison considers the optimal fuel burn predicted by the Breguet rangeequation at a single cruise point. This initial singlepoint optimization comparisondemonstrated a limited fuel burn savings of less than 1%. Given the effectiveness ofthe passive aeroelastic tailoring in the optimized non-morphing wing, the singlepointoptimization offered limited potential for morphing technology to provide any bene-fit. To provide a more appropriate comparison, a number of multipoint optimizationswere performed. With a 3-point stencil, the morphing wing burned 2.53% less fuelthan its optimized non-morphing counterpart. Expanding further to a 7-point stencil,the morphing wing used 5.04% less fuel. Additional studies demonstrate that the sizeof the morphing device can be reduced without sizable performance reductions, andthat as aircraft wings’ aspect ratios increase, the effectiveness of morphing trailingedge devices increases. The final set of studies in this thesis consider mission analy-sis, including climb, multi-altitude cruise, and descent. These mission analyses wereperformed with a number of surrogate models, trained with O(100) optimizations.These optimizations demonstrated fuel burn reductions as large as 5% at off-designconditions. The fuel burn predicted by the mission analysis was up to 2.7% lower forthe morphing wing compared to the conventional configuration.

[发布机构] University of Michigan

[效力级别] aerostructural optimization

[关键词] multidisciplinary design optimization;aerostructural optimization;morphing trailing edge;Aerospace Engineering;Engineering;Aerospace Engineering