Dynamic squeeze film rheometry for flat and spherical geometries using nonlinear spectral analysis

Abstract

In this paper, the effect of plate skewness is considered in squeeze film viscometry for Newtonian liquids. Film dynamics are derived for parallel and inclined configurations in the case of flat and spherical geometries, and the analytically derived results are then compared with experimental data obtained using a Micro Fourier Rheometer. The susceptibility to plate skewness for the different geometries is assessed by measuring viscosity of a silicone oil standard. In order to obtain viscosity estimates, nonlinear spectral analysis techniques are used based on the theoretically derived equations, and the measured plate force and motion. Good agreement between predicted and experimental values is achieved, indicating that a spherical plate provides a much more robust estimate of viscosity compared to flat plate geometry.