Flow-induced birefringence study of secondary flow in entrance region of rectangular slit channel for long-chain-branched polyethylene melt

This work presents an analysis of the inner boundary secondary flow (i.e., corner vortex flow) in entrance region a rectangular slit channel for long-chain-branched polyethylene melt evaluated using particle tracking and stress-induced birefringence measurements. Further, flow-induced technique was used to investigate effects temperature shear rate on size entry flow. Obtained results trends were compared with laser-Doppler velocimetry data taken from open literature same polymer comparable conditions. Interestingly, both methods very similar. suggests that measurements may be useful tool investigating flows melts.