Smart Vortex Generator Transformed by Ambient Temperature Change

The concept of a smart vortex generator (SVG) is proposed. The SVG has an upright position when acting as a vortex generator during takeoff and landing, and a stowed position when cruising. This SVG consists of a shape memory alloy (SMA) plate that memorizes the upright position near the ground at high temperatures and a blade spring hooked to the SMA plate that moves the plate into the stowed position when exposed to low temperatures associated with high-altitude cruising. To study the deformability of the SVG, numerical simulations were performed using a simple mathematical model. The results revealed that the temperature of the SVG can smoothly follow the changes in ambient temperature both in ascending and descending phases, and that the SVG can vary its shape from the upright position to the stowed position and vice versa according to the ambient temperature without requiring additional energy. Moreover, it was found that the temperature range for deformation depends on the stiffness of the spring, and that the degree of deformation depends not only on the stiffness of the spring, but also on the martensite variants which appear when cooled.