| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 96 === Piezoelectric fans are solid-state resonant devices that use piezoelectric excitation to drive a thin blade into resonance to create a fluid flow for cooling electronic devices. These fans are of low power consumption, small size, low noise and long lifetime.
The objective of the present study is developing a finite element analysis model to investigate the static and dynamic characteristics of the piezoelectric fan. First, this study develops the constitutive equations for the piezoelectric fan. Then use the Hamilton’s principle and finite element approximate solutions to derive the finite element equations of motion for the piezoelectric fan. The present study uses four types of elements, i.e., three-dimensional solid element, piezoelectric three -dimensional solid element, shell element and solid-shell transition element, to model the bulk and plate portions of the piezoelectric fan, respectively. The solid-shell transition element lies between 3-D solid element and shell element to achieve the conformity requirement of a finite element model.
The present finite element model and the method for computing the eigenvalues and eigenvectors are adopted to find the natural frequencies and vibration modes of the piezoelectric fans. The present finite element equations of motion of the fans are solved by the Newmark direct integration scheme to simulate the dynamic responses of the fans subjected to the externally applied alternating voltages. The present results are compared with that of the finite element model with 3-D solid elements only to verify the accuracy and efficiency of the present finite element model of the piezoelectric fan.
|
|---|
