To address the limitations of conventional one-dimensional longitudinal vibration transducers in terms of single-directional acoustic radiation and limited radiation area, this study proposes a novel longitudinal-bending orthogonal coupled piezoelectric ultrasonic vibration system(The vibration schematic diagram of the vibration system is shown in Fig.16.). By synergistically integrating the orthogonal longitudinal vibration of a sandwich-type piezoelectric transducer, displacement amplification via conical horns, and flexural vibration of metal disks, the system achieves two-dimensional four-directional large-area ultrasonic radiation.
A combination of theoretical modeling, finite element simulation, and experimental validation was employed to investigate the system's dynamic characteristics. First, an electromechanical equivalent circuit model was established based on coupled vibration theory and electro-mechanical analogy principles, from which resonance/anti-resonance frequency equations were derived. Subsequently, finite element simulations using COMSOL Multiphysics were conducted to analyze impedance responses, vibration modes, and acoustic radiation characteristics in air. Finally, prototype fabrication and performance verification were performed through impedance analyzer measurements, laser vibrometry, and ultrasonic de-misting experiments.
Theoretical predictions of anti-phase (22,871 Hz) and in-phase (23,016 Hz) resonance frequencies showed relative errors below 3.7% compared to experimental results (22,086 Hz and 22,196 Hz). Finite element simulations combined with experimental validation confirmed the excitation mechanism of 5th-order flexural vibration in the disks. Acoustic directivity patterns revealed a multi-beam radiation pattern with coexisting main lobes and side lobes(The directional patterns under anti-phase and in-phase vibration modes is shown in Fig.17.), while in-phase vibration mode demonstrated higher ultrasonic radiation intensity in the near-field region. Furthermore, under 200 W input power, the system reduced smoke concentration within 70 seconds, demonstrating its feasibility for gas treatment applications.
By leveraging the synergistic effect of orthogonal longitudinal coupling and flexural vibration, this design overcomes the limitations of traditional transducers and provides theoretical and technical support for high-power multi-directional acoustic radiation. The research outcomes offer promising solutions for applications in ultrasonic dust removal, defoaming, and other gas-phase processing fields.
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