  We have developed a new multiscale simulation technique to investigate
history-dependent flow behavior of entangled polymer melt, using a smoothed
particle hydrodynamics simulation with microscopic simulators that account for
the dynamics of entangled polymers acting on each fluid element. The multiscale
simulation technique is applied to entangled polymer melt flow around a
circular obstacle in a two-dimensional periodic system. It is found that the
strain-rate history-dependent stress of the entangled polymer melt affects its
flow behavior, and the memory in the stress causes nonlinear behavior even in
the regions where ${\rm Wi} \le 1$. The spatial distribution of the
entanglements $<Z>$ is also investigated. The slightly low entanglement region
is observed around the obstacle and is found to be broaden in the downstream
region.
