In part 2 of the paper simplified unsteady-mass (and momentum-) balance equations of melt polymer resin in the cavities of GAIM were proposed, as a time-dependent rule of thumb, to constitute a novel flow model in GAIM under the configuration of two fan-shaped geometries connected with a gas nozzle. Upon performing a simulation on them with commercial software (MOLDFLOW), we compared the time evolution of simulated gas penetration lengths with the those of unsteady trajectory on the gas flow in GAIM by the suggested novel flow model in the fan-shaped cavities in order to check the precision of model-predicted gas penetration lengths as well as the consistency of its predicted direction. The results by the suggested novel flow model were satisfactory to fit the trajectory simulated with commercial software (MOLDFLOW).