Entry-flow calculations for the Oldroyd-B and FENE equations

摘要: Abstract Entry-flow calculations are presented for the Oldroyd-B and FENE equations in limit of high contraction ratio both planar axisym- metric geometries. In addition to abrupt entry flow a cone-shaped half-angle π/4 is also considered. A decoupled finite-difference scheme used with time stepping converge solution non-linear equations. For stress equation streamline integration technique developed. it found that reordering elliptic operator stream function enables larger steps be taken at We when polymers near full extension. These show can predict much vortices than regime spring. No observed only weak axisymmetric. cone flow, again predicted but they remain localised entry, manner similar lip vortices. Pressure drops considered argued non-dimensional decrease pressure drop compared Newtonian should linear equation. An estimate this made , low concentration, limits.