航行中螺旋桨产生鸣音是由于在桨叶()以外的部位产生有规律的涡流,在某些转速下涡流引起的振动频率与桨叶固有频率接近而产生共振所致。 A、随边0.4RB、随边0.7RC、导边0.4RD、导边0.7R
航行中螺旋桨产生鸣音是由于在桨叶()以外的部位产生有规律的涡流,在某些转速下涡流引起的振动频率与桨叶固有频率接近而产生共振所致。
A、随边0.4R
B、随边0.7R
C、导边0.4R
D、导边0.7R
相关考题:
关于螺旋桨鸣音,下列不正确的说法是()。 A、在螺旋桨工作时发出的“嗡嗡”的响声B、导边涡流激振力引起的桨叶振动C、实质上是共振D、随边0.4R以外部位的涡流引起的振动频率与桨叶固有频率接近所致
66、在鱼洗实验中,下列哪个说法是正确的? In the fish washing experiment, which of the following statements is true?A.当鱼洗器壁的振动频率越来越接近于鱼洗固有频率时,产生共振现象; Resonance phenomenon occurs when the vibration frequency of the wall of the fish washer is closer and closer to the natural frequency of the fish washer;###SXB###B.当鱼洗器壁的振动频率大于鱼洗固有频率时,产生共振现象; Resonance phenomenon occurs when the vibration frequency of the wall of the fish washer is greater than the natural frequency of the fish washer;###SXB###C.当鱼洗器壁的振动频率小于鱼洗固有频率时,产生共振现象; When the vibration frequency of the fish
在鱼洗实验中,下列哪个说法是正确的? In the fish washing experiment, which of the following statements is true?A.当鱼洗器壁的振动频率越来越接近于鱼洗固有频率时,产生共振现象; Resonance phenomenon occurs when the vibration frequency of the wall of the fish washer is closer and closer to the natural frequency of the fish washer;#B.当鱼洗器壁的振动频率大于鱼洗固有频率时,产生共振现象; Resonance phenomenon occurs when the vibration frequency of the wall of the fish washer is greater than the natural frequency of the fish washer;#C.当鱼洗器壁的振动频率小于鱼洗固有频率时,产生共振现象; When the vibration frequency of the fish