Study on liquid-jet cooling and heating of the moving SMA actuator

In this paper the numerical simulation and experiment were performed to investigate liquid-jet cooling and heating of the moving SMA (shape memory alloy). Two-dimensional unsteady flow was solved using the laminar flow model and energy conservation equation. The solid region was simulated by coupling the fluid with moving boundary and static boundary condition at the fluid–solid interface, respectively. Results showed that separation on the moving SMA surface was observed for the heating process and some vortices away from the moving surface were induced for the cooling process. A subatmospheric region on the impingement surface was observed with the increase of the streamwise distance from the stagnation point. The temperature of SMA actuator was compared for static and moving surface at different exit velocities, jet periods and nozzle-to-surface distances. The shape deformation of the actuator increased with the increase of the jet velocity and period, decreased with the increase of the nozzle-to-surface distance. An experiment on jet impingement was set up to study the liquid-jet cooling and heating the SMA actuator. The results of the numerical simulation were in good agreement with the experimental data.