Modeling and analysis of double fractional order Jeffreys viscoelastic fluids flow

Abstract

In this paper, the rheological properties of welan gum solutions with mass fractions of 2%, 3% and 4% are measured using an Anton paar MCR 302 rheometer. It is found that the liquids fit the five-parameter Jeffreys model of double fractional order with corresponding rheological parameters. The behaviors of these fluids over linear stretching surface are studied based on the experimental results. We find that, compared with the Newtonian fluid, there exists an inflection on viscoelastic fluid velocity curve, which separated velocity curve into two parts with different concave-convexity. For the interval from inflection to external boundary, which similar to Newtonian fluid, the viscosity plays a major role, while for the interval from stretching surface to inflection, the elasticity plays a major role. At the inflection, the velocity gradient curve arrives its extreme. It is also found that, as viscoelastic solutions mass fractions decrease, the thickness boundary layer becomes thinner and the elasticity effect is weakened. Those results reveal the complex physical mechanism of viscoelastic fluid film flow and provide a theoretical basis for relevant engineering design.