flap nozzle meaning in English

活瓣喷口
活动喷嘴

However , by comparison with flap nozzle servo valve which has been used widely and popularly by now , the torque motor of jet pipe servo valve has a larger rotary inertia . this causes low natural frequency of servo valve , and thus the response speed of jet pipe servo valve is slow . moreover , the jet pipe of servo valve has large flexibility , and it is easy to excite oscillations and noise in the valve , which is named self - excited oscillations and noise
然而与目前普遍使用的喷嘴挡板伺服阀相比,射流管伺服阀的衔铁组件转动惯量大,导致力矩马达部分固有频率低,从而响应速度慢,此外,射流管供油管柔性大,容易产生自激现象,这些缺点都使得射流管伺服阀的动态特性差,从而影响了它的工作性能。