Two-dimensional heat transfer of jet impinging on shape memory alloy actuator

The SMA (shape memory alloy) actuator heated and cooled by jet impingement was investigated numerically and experimentally. Two-dimensional incompressible and unsteady flow (both hydrodynamically and thermally) is solved using the standard k-Ε turbulence model and energy conservation equation. The solid region is simulated by coupling the fluid with the moving and static boundary condition at the fluid-solid interface, respectively. The temperature of the actuator for the static boundary condition is a little higher than that for the moving boundary condition. The results show that the difference of temperature and the shape deformation on the surface of SMA increase with the increasing of exit velocity and jet periods. An experimental apparatus about periodic jet impingement was set up to study the heat transfer of the jet gas and the SMA actuator. The model results are found to compare favorably with the experimental data.