On forcespinning of nonlinear rotating jets of viscoelastic Boger fluids

•Strong tensile force or stretching force makes jet of Boger fluid very thin.•Jet in three-dimension moves much faster than jet in two-dimension.•Strong centrifugal force can make jet thinner with increasing arc length.•Three-dimensionality of jet & presence of gravity are destabilizing.•High rotation & viscoelasticity can make jet of Boger fluid very thin. We consider forcespinning (FS) of nonlinear three-dimensional rotating viscoelastic jets of Boger fluids and in the presence of gravity effect. In FS process, a fluid jet is forced through an orifice of a rotating spinneret leading to the formation of a curved jet. Applying the upper-convected Maxwell constitutive model for the stress tensor part of the governing non-Newtonian jet system and using scaling and perturbation methods, we develop a model for the jet system. We determine the nonlinear solutions for the jet quantities such as the radius, speed, stretching force, compressive force, tensile force and the jet centerline, and we calculate these quantities for different values of the jet arc length and the parameters representing rotation, viscoelasticity, gravity, surface tension and polymer viscosity. We find that the effects of rotation, relaxation time, gravity and three-dimensionality of the modeling system on the jet of Boger fluid can be significant. Beyond a very short distance from the jet exit, the jet speed, tensile force, stretching force and the jet curvature are notably increased and the jet radius is much reduced with increasing the viscoelasticity, rotation rate and the jet arc length. Strong tensile force or stretching force corresponds to weak compressive force and very thin jet of Boger fluid.