THE CONTRIBUTION OF RADIATION AND VISCOUS LOSS IN A FLUID LOADED FLEXURAL PLATE WAVE SENSOR

✍ Scribed by J.L. Dohner

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 256 KB
• Volume: 217
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1998.1729

✦ Synopsis

In this paper a study of radiation and viscous losses in a fluid loaded Flexural Plate Wave (FPW) sensor is presented. Previous to this study, it was believed that supersonic radiation was the dominant mechanism of damping in FPW devices. However, because no previous theory had been developed to model finite length effects, this belief was never challenged. In this paper it will be shown that the dominant mechanism of damping can not only be due to supersonic radiation, but also to a fluid/structure resonance which enhances viscous loss. The equations of motion for a single port FPW sensor plate are derived and coupled to the equations of motion for a Newtonian fluid. These coupled equations are solved by using a wave number transform approach. The resulting solution is comprised of terms derived by Wenzel, plus additional terms representing diffracted wave dynamics. It is shown that significant viscous damping occurs when a resonance involving diffracted wave dynamics is excited.