FSI of viscosity measuring mechanical resonators: theoretical and experimental analysis

Abstract

Measuring viscosity online in processes is crucial to maintaining the quality of many chemical and biological processes. The damping induced by the liquid around the resonator is used to determine the viscosity of the liquids. Typical viscosity sensors are probe style and obstruct the piping system, disturbing the flow and creating a potential source of contamination in critical processes. The eventual goal is to design a non-intrusive sensor capable of accurately measuring the viscosity of the liquids without influencing the flow within the pipe. In order to get a deeper insight into the functionality of such a device, a mathematical model has been developed describing the mechanical vibration coupled with the fluid-structure interaction (FSI) models. The shear stresses at the wall have been analysed using the computational fluid dynamics tool OpenFOAM and have been integrated into the derived model. For validation, the model has been tested against the samples. The model is capable of accurately predicting the response of the sensor and can be used as an optimization and design tool.