Analysis of acoustic radiation and viscous damping on the vibration of piezoelectric circular microdiaphragms

In this study, an analytical calculation was performed by using the Navier-Stokes equation for Newtonian fluids to investigate influences of acoustic radiation and viscous damping on the frequency and quality factor of piezoelectric circular microdiaphragms (PCM). Theoretical model shows that the ratio of contribution of viscosity over acoustic radiation term on the frequency shift of PCM mainly depends on (υ/h_cp)^0.5. This means, besides the kinematic viscosity, the thickness and the sound velocity in the plate are also two significant parameters in viscosity influences on the frequency shift of PCM. Throughout the work, theoretical and experimental values were compared and fairly good correlation was observed.