Morphing cover for front fender opening using SMA hinge to reduce aerodynamic drag

We are developing a morphing panel that uses shape memory alloys to enclose the front wheel-house opening. This is highly desirable to reduce the aerodynamic drag of automobiles, and improve fuel economy. The front fender has a large opening for clearance while turning. It has been estimated that the aerodynamic drag can be reduced by about 7-8% if the wheel opening is enclosed. However, such an enclosure can interfere with the wheel during turning maneuvers, so we have designed a morphing cover that can change shape depending on the wheel turn direction: preventing interference. A fender cover panel that can change shape from flat to semi-hemispherical, while withstanding aerodynamic pressure has been developed. Further, compact and lightweight distributed hinge actuators have been developed to integrate into the panel to trigger the shape change. This paper will show how such designs are realized, along with target performance.