Multicellular piezoelectric actuator for setting in motion fluids, and heat exchange enhancement

In this paper, a multi-cellular piezoelectric actuator has been dimensioned, designed and integrated into an electro-active morphing wall heat exchange demonstrator. The design study was performed using finite element simulations. Numerical study shows that the obtained deflections vary from 77 to 462 μm for applied displacement ranging from 3 to 18 μm. Once the operating principle validated, a series of actuators has been machined and tested. Dynamic tests (unloaded) gives a maximum displacement about 230 μm for a frequency ranging up to 100 Hz. However the static tests give results with a good agreement with simulation. The developed actuators have been introduced into a demonstrator to show the feasibility of an intensification of heat exchange by electro-active morphing. The recovered data have demonstrated the feasibility of pumping for a traveling wave of 5 Hz closing quasi-totally the channel. Another result is the reduction of wall temperatures during the application of a traveling wave on the, thereby that the heat transfer was intensified. Moreover, an increase in the rate of flow was observed. All this results demonstrate the enhancement of heat transfer.