To improve the drag reduction efficiency of a winglet under off-design conditions, this paper presents a morphing winglet concept that utilizes shape memory alloy (SMA) spring actuators to change the cant angle of the winglet and optimize the drag characteristics of an aircraft under various flight conditions. The required SMA spring actuators are designed through a coupling design method, and the morphing capability of the morphing winglet is validated by finite element analysis and wind tunnel test. Finally, a closed-loop control for the morphing winglet is presented. The results show that an active cant angle of 23° can be achieved within 1 min in the takeoff phase of a flight (with the freestream velocity is 26 m/s and the angle of attack is 3°). The maximum error of control precision is less than 12%. The testing results agree well with the design specifications.
LI Wei, XIONG Ke, CHEN Hong, ZHANG Xu, SU Yonggang, REN Zhiyi
. Research on Variable Cant Angle Winglets with Shape Memory Alloy Spring Actuators[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2012
, 33(1)
: 22
-33
.
DOI: CNKI:11-1929/V.20111031.1056.002
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