翼身融合布局民机克鲁格襟翼设计

翼身融合（BWB）布局是"绿色航空"发展目标的下一代大型民用飞机的理想布局。由于高度融合的外形特点，BWB布局难以通过应用传统增升装置实现低速增升与配平的协调设计。本文采用开缝钝头克鲁格襟翼提高BWB布局低速失速特性。首先，构建了克鲁格襟翼二维参数化方法，该方法符合克鲁格襟翼运动机构特点，可准确描述几何外形与缝道配置。其次，开展克鲁格襟翼几何参数与偏转角度的影响规律研究，分析流动形态与增升机理，提出设计原则。综合考虑外形、运动机构与遮蔽效应等设计约束，以提高增升能力为目标，开展前缘开缝克鲁格襟翼优化设计。优化设计结果满足设计约束，数值分析表明其增升能力比初始外形与经典缝翼均有明显提高。最终，采用前缘开缝克鲁格襟翼与后缘简单襟翼构建BWB增升构型，数值模拟与风洞试验结果表明，增升方案能够实现升力系数要求，降低了对配平能力的需求，减小了增升装置和高升力配平设计压力。提出的克鲁格襟翼设计方法不仅适用于BWB布局，也为传统布局民机增升装置设计提供了技术支持。

Design of Krueger flap for civil aircraft with blended-wing-body

The Blended-Wing-Body (BWB) is the most promising candidate for the next generation transport to achieve "green aviation". Due to its unique blended geometric characteristics, the low speed characteristics of BWB can hardly gain enough lift under trimmed condition by applying the traditional high-lift device. The slotted bull-nose Krueger flap is applied to improve the low speed stall characteristics of the BWB configuration. Firstly, a two-dimensional parameterized method for the slotted bull-nose Krueger flap is established to accurately describe the geometry and deployed settings, which accord with the characteristic of actuating mechanism. Then, the effects of Krueger geometry parameters and the deflecting angle are investigated, during which the features of the flow phenomena and high-lift mechanism are studied, and several design principles are proposed. After that, with considerations of geometry, mechanism, and shielding effect constraints, an optimization is conducted to enhance the lift improvement towards a more practical Krueger design. The optimization results for leading edge device satisfy the design constraints and show promising aerodynamic features compared with the initial design and a classic slat design. Finally, a BWB high-lift configuration consisting of leading edge slotted bull-nose Krueger flap and trailing edge simple-hinged flap is established. The aerodynamic characteristics of leading edge device are obtained by numerical simulation and the entire high-lift configuration is studied through wind tunnel experiments. The result shows that this kind of high-lift device is suitable to relieve the pressure of trim and realize sufficient lift gain. The study proves that the Krueger design methodology is suitable for further research and could be applied as a high-lift device for both conventional and innovative configurations.