Development of a SMA-based actuator for compact kinetic energy missile

In this paper, a prototype SMA-based actuator for a compact kinetic energy missile was fabricated. Thin film nickel-titanium was selected as an actuating mechanism because it exhibited high power density compared to other smart materials. This study represents a proof of concept that high drive frequency and high power density can be both achieved with thin film SMA. The thin film reached a drive frequency of 80Hz while achieving a power density of 27900 Watts/kg. As for the pump, the power density was 2.93 Watts/kg, but obtaining higher value can certainly be achieved by reducing the chamber weight through optimization. In any case, CFD analysis revealed that the pump chamber had to be redesigned to change the flow profile because the present design created non-circulating dead zones immediately adjacent to the diaphragm. Therefore by redirecting the liquid flow to directly cool the SMA diaphragm improved the heat transfer and thus improved performance of the actuator can be achieved.