The increasing demand for air transportation makes it critical to consider environmental issues such as noise and fuel consumption in aircraft design and optimization procedures. In this thesis, an integrated framework is developed to design low-fuel consumption aircraft with trailing-edge noise consideration by performing aerodynamic shape optimization (ASO)....[ Read more ]

The increasing demand for air transportation makes it critical to consider environmental issues such as noise and fuel consumption in aircraft design and optimization procedures. In this thesis, an integrated framework is developed to design low-fuel consumption aircraft with trailing-edge noise consideration by performing aerodynamic shape optimization (ASO).

The framework is realized by integrating a trailing-edge noise prediction model into a detailed flight performance analysis procedure, which efficiently emulates aircraft operation from takeoff to landing and computes flight-mission range, time, and fuel burn. To make this framework suitable for optimization and ensure computational tractability, surrogate models are constructed and used to replace expensive aerodynamic and aeroacoustic computations.

A hybrid method has been devised to enable the systematic integration of operational data into this framework. Through the developed mission parameterization process, nominal parameters are substituted by the extracted mission and speed profiles. In addition to the mission-based ASO, which optimizes the baseline airfoil under realistic flight conditions, a state-of-the-art single-point optimization is also performed for comparison purposes.

As expected, the mission-based optimization result shows a simultaneous reduction in fuel consumption and trailing-edge noise. Meanwhile, the single-point optimum reduces the trailing-edge noise at the expense of higher fuel consumption in medium- and long-haul flights. This tradeoff between aerodynamic performance in the transonic region and aeroacoustic performance in the low Mach region cannot be revealed and properly analyzed without including flight mission analysis in the optimization loop.

Although the aeroacoustic performance of the mission-based optimum in the low Mach region is not better than that of the baseline airfoil under the same fixed flight condition, the mission-based optimization formulation can still reduce the maximum trailing-edge noise in the landing and takeoff cycle, thanks to the enhanced aerodynamic properties throughout the entire mission.

The results presented in this thesis clearly demonstrate the benefits of considering the full flight operating envelope, with reference to real data, in the ASO procedures. The developed solution approach enables more realistic performance and tradeoff assessments of fuel consumption and trailing-edge noise with airfoil geometry changes while maintaining computational efficiency.