Consequently, a very small area ratio results in a very large resistance, and when
therefore the resistance
resulting in a zero gate velocity (like a closed valve).
Conversely, for a large area ratio, the resistance is insensitive to variations of
the gate area and the velocity is reduced with increase the gate area.
Therefore a maximum gate velocity must exist, and
can be found by

which can be solved numerically. The solution of equation () requires full information on the die casting machine.

A general complicated runner design configuration can be converted into a straight
conduit with trapezoidal cross-section, provided that it was proportionally designed
to create equal gate velocity for different gate locations^{18}.
The trapezoidal shape is commonly used because of the simplicity, thermal,
and for cost reasons.
leave it for now, better presentation needed

= 100 true mm

= 100 true mm

copyright Dec , 2006

The pdf version is also available here