This paper aims to present a novel airflow-induced acoustic piezoelectric generator that can be used to solve the problem of insufficient power supply of modern intelligent fuzes. The sound waves induced by airflow are the key to power generation performance. It is proposed that an edge tone frequency equal to the acoustic mode frequency is a sufficient condition for evoked acoustic waves, and a design idea and scheme for a universal fuze power supply is provided. We establish the vibration model of the airflow-induced acoustic piezoelectric generator. According to the model, the experimental research on the power generation performance shows that the sound pressure frequency, vibration displacement frequency, and output voltage frequency are consistent. The model provides a design idea for a vibration sensor. At the flow rate of 100.8 m/s, the output power is 45.3 mW, which is much higher than the fuze power sources such as the magnetic backseat generator. Therefore, the airflow-induced piezoelectric generator can effectively solve the problem of the modern fuze less types of power supply and low output energy.
In the field of new environmental energy harvesting technology, wind energy and piezoelectric energy harvesting have become research hotspots. By utilizing wind energy into vibration energy, i.e., wind-induced vibration effect is a research hotspot in the field of environmental energy harvesting. This article comprehensively analyzes the research status and development trend of piezoelectric energy harvesters based on wind-induced vibration effects at home and abroad. It was found that the conversion process of wind energy to vibration energy is mainly based on flutter, galloping, and acoustic resonance. The conversion of vibration energy into electrical energy is mainly piezoelectric power generation, supplemented by magnetic induction power generation and friction power generation. For high power density and small volume application scenarios, resonant cavity type wind vibration energy collection is the main development trend.
1 February 2020 in International Journal of Applied Electromagnetics and Mechanics
The lanthanum-doped lead zirconate titannate (PLZT) ceramic has shown its potential applications as light-controlled micro actuators activated by ultraviolet light for the photovoltaic effect in the field of micro-driven. Aiming to the slow response of photostriction of PLZT ceramic, the primary purpose of this article is to propose a light-controlled actuator with the novel opto-electrostatic hybrid driving based on PLZT ceramic. The mathematical model of the proposed light-controlled actuator is established on basis of the anomalous photovoltaic effect model of PLZT ceramic. The actuation characteristics of the micro actuator are investigated based on the established mathematical model and the experiments of the photovoltage of PLZT ceramic. Furthermore, the actuation curves of the micro actuator driven by opto-electrostatic hybrid driving based on PLZT ceramic are acquired to verify the rationality and feasibility of the light-controlled micro actuator design. So according to the analysis and experimental results, the light-controlled actuator driven by the novel opto-electrostatic hybrid driving based on PLZT can conduct the effectively and precisely displacement control with fast response speed. In addition, the driving method based on the novel opto-electrostatic hybrid driving has advantages of non-contact control, remote control and no electromagnetic interference, etc.
This paper aims at the power generation requirements of the fuze airflow-induced acoustic generator, analyzes the influence of structural parameters on the fluid power sound source, which is related to the power generation performance and use performance of the generator. In this paper, the orthogonal experiment method is used to study the sensitive parameters that control fluid dynamic sound sources. The results show that the annulus, the confronting distance, and cavity length can all have an impact on the sound pressure amplitude, and the sound pressure amplitude is most sensitive to the change of the confronting distance. However, the length of the resonant cavity has the most significant effect on the sound pressure frequency. The size of the annulus has a weak effect on the sound pressure frequency, and the confronting distance has almost no effect on the sound pressure frequency. The optimal combination scheme with the highest output power is selected according to the sensitive parameters. In addition, the empirical formula for the vibration frequency of the airflow-induced acoustic generator in the short resonant cavity was revised, and the influence of the annular gap on the vibration frequency was added, and the influence factor α = 0.3 was determined. The corrected frequency empirical formula has the smallest error between the theoretical value and the experimental value, and can be used as an effective method for estimating the vibration frequency. This provides a reference for the engineering design of the fuze airflow-induced acoustic generator, which has high military value and application prospects.
Piezoelectric transducers, which convert airflow induced vibrational energy into electrical energy, can be applied to self-powered supply and auxiliary power supply for various aircraft electronic systems. Micro-ringtone airflow piezoelectric generator, designed by the principle of airflow induced acoustic, is one kind among them. The vibrating piezoelectric generator, is usually mounted on the aircraft during the flight. The incoming airflow produces hydrodynamic acoustic source, which is the vibration source of the piezoelectric generator, actively vibrates the piezoelectric plate to convert energy. According to the vibration theory, a one-dimensional vibration model of piezoelectric generator with fixed peripheral pressure, under hydrodynamic excitation is established. The vibration and frequency characteristics of the piezoelectric transducers are analyzed by measuring the sound pressure and the piezoelectric generator voltage. Theoretical analysis and experimental results show that the frequency of hydrodynamic acoustic source is slightly lower than that of piezoelectric generator’s natural frequency. Maximum output power is obtained when the inflow speed is in the range of 128 m/s-148 m/s, the corresponding hydrodynamic acoustic source frequency is 6.9 %-8.7 % lower than the natural frequency of the piezoelectric generator. Excitation force and the displacements of piezoelectric plate are in same frequency. But is ahead of phase angle than the displacement of piezoelectric plate.