The Inertial Effects on the Flow Pattern in a Gas-assisted Injection Molding Process

摘要

The flow field of the long bubble steadily expelling a viscous fluid confined by two closely located parallel plates is examined. Using a theoretical bubble's profile to depict the procedure for computing the free surface and flows simultaneously can reduce the computing time of tracing the free surface. It is helpful to search the influence of bubble size on the flow field. It shows not only the two typical flow patterns (complete bypass flow and recirculation flow) but also examined the migrant phenomenon of the stagnation point moving at the region of bubble tip front. The increment of ratio of asymptotic bubble width to the half width of confined fluid (i.e. λ) to stimulate the movement of stagnation point lays in 2 3<λ<0.6839 for Re = 0, and the stagnation point is very sensitive to any increment of λ with Re>100. The value of (x_(sp))~* decreases in λ or Re increasing situation, but the reverse effect on (y_(sp))~* y is observed.