Viscous flow through a thin‐walled elastic hollow ellipsoid—Experiments to demonstrate a potential flowmeter

Abstract

Large deformation of an elastic hollow ellipsoid may be used as the mechanism of a flowmeter. It is seen as being inspired by human biology, when passing through fluid internally. The investigation on this potential was carried out where simply the relationships among pressure drop across an ellipsoid, deformation, flowrate and fluid viscosity were obtained. The elastic hollow ellipsoid was made from Silicone, which has a long axis of 0.05 m, a short axis of 0.03 m, and a wall thickness of 3.5 × 10−4 ± 4.6 × 10−5 m. A monotonic relationship between fluid flowrate and a representative diameter of the ellipsoid was found. Sodium carboxymethyl cellulose (CMC) aqueous solutions were used as a more viscous media so the effect of viscosity was explored. Unlike the firm result on flowrate gauging, it was inconclusive on differentiating the effect of viscosity. When the inlet and the outlet of the fluid were switched over, the geometrical expansion of the ellipsoid was found to be sensitive to the small spatial variation of wall thickness (a non‐uniformity caused by manufacturing limitation). Nevertheless, this work has demonstrated an interesting flowmeter and further explorations on viscosity effect may be warranted.