3.4.1 Utilizing semi dimensional analysis for characteristic time

The characteristic time scales determine the complexity of the problem. For example, if the time for heat transfer/solidification process in the die cavity is much larger than the filling time than the problem can broken into three separate cases 1)the fluid mechanics, the filling process, and 2)the heat transfer and solidification 3) dissipation (maybe considered with solidification). Conversely, the real problem in die filling is that we would like to the heat transfer process to be slower than the filling process to ensure a proper filling. The same can be said about other processes.