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.
ZHANG Minghui
,
CHEN Zhenli
,
MAO Jun
,
WANG Gang
,
TAN Zhaoguang
,
WANG Long
,
ZHANG Binqian
. Design of Krueger flap for civil aircraft with blended-wing-body[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2019
, 40(9)
: 623048
-623048
.
DOI: 10.7527/S1000-6893.2019.23048
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