infrasonic frequency是什么意思

用法例句

The results indicate that:(1) for high subsonic inlet flow,the boundary layer in blade suction surface being aspirated can increase the cascade pressure rate and flow turning angle,but not always reduce flow loss;(2) for middle subsonic inlet flow,the boundary layer in blade suction surface being aspirated can increase the cascade pres.

结果表明:(1)对于高亚声速压气机叶栅,采用吸力面附面层吸除可提高叶栅的扩压度,但不一定能减小流动损失。

It is emphasized that the kind of extremely low altitude, subsonic winged missiles should play a key role in the future, and some supersonic and combined winged missiles should be developed actively and gradually so as to b.

根据国外飞航导弹的发展趋势 ,从体系角度提出了“有的放矢”的指导思想和“效费比”评价准则 ;强调了超低空、亚声速飞航导弹的主导地位 ;指出积极稳妥地发展超声速飞航导弹和组合式飞航导弹 ,形成近、中、远、洲际全程覆盖对地、对海、对信息链实施精确打击的飞航导弹体系的意义 。