With increase of amplitude or reduction of frequency of the entrance pressure, both of the amplitude of velocity and that of pressure within the die become larger, which can be observed more clearly for the case of larger amplitude of entrance pressure.

• 当入口压力的振幅增大或频率减小时 ,口模内压力和速度的振幅都增大 ,并且入口压力振幅越大这种现象越明显。