Newtonian die swell evaluation for axisymmetric tube exits using a finite element method

Using a finite element method, a value of 13.2 per cent is obtained for the die swell of a highly‐viscous Newtonian fluid flowing at very low Reynolds number from a circular tube of constant radius. The same method is then used to obtain die swell values for a variety of axisymmetric tube exits. It is found that, in general, conical constrictions at or near the tube exit result in a decrease in die swell, while conical expansions increase the die swell.