Disturbance degree of the apparent phase velocity increases with decrease of frequency until a maximum one occurs.
表观相速度扰动程度随频率减小而增加，直至出现大扰动。
2
A finite dimensional repetitive control method is proposed for the high precision velocity control of servomechanisms subject to significant nonlinear disturbance torque.
提出了一种有限维重复控制方法，以实现对有严重非线性扰动力矩的伺服机构的高精度速率控制。
3
The results show that the wavy interface and vortex street are caused by the velocity distribution of shear flow and periodic disturbance at the interface.