When the turbine rotational speed is 34,586 r/min, the system isentropic and electromechanical efficiencies achieve the maximum values of 83.6% and 65.3% respectively.
This study uses a special configuration of electrodes for piezoelectric plates in experimental measurement of AF-ESPI to improve the electromechanical coupling efficiency of transverse vibration.
The maximum values of angular speed, output torque, and electromechanical transduction efficiency are 225 rpm, 15.736 mN m, and 16.22%, respectively.
Our findings suggest that matching the individual resonances of the fiber optics cable and the piezo-scanner alone, leads to optimum electromechanical conversion efficiency.
A challenge in polymeric piezoelectric materials is that their electromechanical coupling efficiency must be improved to approach that of bulk piezo ceramics.
Each case should be treated independently, since the need in electricity depends on different factors: sea water characteristics, values taken for RO sizing parameters, electromechanical components efficiency... and, last but not least, choice of the system for hydraulic energy recovery of the concentrate.
Compared with the ESSH technique, theoretical and experimental results demonstrate the new technique can improve electromechanical conversion efficiency when the piezoelectric energy harvester is excited under two-mode vibration, especially in the case of higher vibration amplitude of the second mode.
The proposed USM belongs to the bolt-clamped type motor, and the PZT ceramics work with d33 mode, which has high electromechanical coupling efficiency and can improve the mechanical output characteristics.
Even though piezoelectric MEMS resonators are known to possess substantially stronger electromechanical transduction efficiencies than the more traditional capacitive MEMS resonators, parasitic feedthrough remains an impediment for electrical characterization of resonators in liquids.
