The upstream gap is selected to maximize undershoot of the first normal stress difference [N.sub.1] at the die wall caused by flaring.
Gander and Giacomin [3, 4] believe that the step decrease in shear rate in these flared dies can produce stress undershoot. For straight and flared dies with the same orifice, they believe the undershoot causes lower shear stresses at the flared die exit than for the straight die.
Specifically, we wanted to see if a stress undershoot must occur near the die exit for a flared die to suppress die drool.
For example, a barrel zone that runs with high cooling due to high shear heat generation of the screw will drastically undershoot
the setpoint if the screw is suddenly stopped, because the heat load is suddenly removed.
Analysts did have undershoots
in 4 of the last 5 months, however.
Analysts still expect a 225k March nonfarm payroll rise that undershoots
recent gains of 313k in February and 239k in January, though it sits near the 221k average Q4 gain and exceeds the 190k average increase over the past 12 months.
reports revealed modest undershoots
for December housing starts and the January Philly Fed report, though the details of both reports were close enough to assumptions to sustain solid trajectories into 2018.
According to Chin-Hong, although specifications should let you know if the supply causes any voltage overshoot or undershoot when it trips, many datasheets do not provide this information.
The specs will tell you how much of an overshoot or undershoot transient the supply will produce and how long the supply takes to recover from those transients.