Abstract: In the conceptual design phase of the blended-body-wing commercial aircraft, a comprehensive analysis and an optimization platform are established to evaluate the overall performance of the design. The platform takes the geometric parameters of the airliner as the input, and completes the analysis of propulsion, geometry, weight, aerodynamics, and performance modules. An optimization model is built based on these modules. In order to efficiently evaluate the performance of the design and conduct the optimization design, the propulsion analysis module adopts a component-based model; semi empirical methods are used in the weight analysis module; the aerodynamics analysis module adopts the panel method combined with the engineering method; a simplified kinematic method is used in the performance analysis module; and the optimization model uses an evolutionary optimization algorithm with the capacity of parallel calculation. A 555-seats blended wing body commercial aircraft is taken as an example to analyze its performance based on the analysis and optimization platform. The results show that the models used in the platform were reasonable. Single objective and multiobjective optimizations are performed based on the initial design, in which the design variables include aircraft geometry parameters and engine maximum take-off thrust. In the single objective optimization, the maximum take-off weight is minimized. In the multiobjective optimization, the direct operating cost, and approach velocity are considered as the objectives simultaneously. The maximum take-off weight of the single objective optimization is reduced by about 7.17% compared to the initial design. The Pareto front for minimizing both the direct operating cost and the approach velocity shows that the DOC decreases by 8.77% while the approach speed increases by 3.32%.

Key words: blended-wing-body, civil aircraft, aircraft conceptual design, optimization, multidisciplinary