Questions tagged [vibration]

Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. The oscillations may be periodic such as the motion of a pendulum or random such as the movement of a tire on a gravel road.

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1answer
80 views

Why this inertial regulator of dragonfly wing pitch reduces self-excited coupled flapping and feathering vibrations and improves gliding flight speed

The pterostigma of insect wings an inertial regulator of wing pitch is linked in this answer to Why do dragonflies have these special little spots on their wings? (open access copy here) The Summary ...
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What are the expected vibration frequencies in a co-axial rotor system with contra-rotating propellers?

I am trying to understand the frequency spectrum of a co-axial rotor system. Form now i have a RC helicopter with two sets of three gear systems arranged in parallel, The number of teeth are 7,23,27) ...
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5answers
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Why do most radial engines use an odd number of cylinders?

To help suppress vibration, most 'V' and 'horizontal' engines use an even number of cylinders as closely opposed as possible. Radial engines are well known for excessive vibration. For some reason ...
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1answer
358 views

What could cause lower torque than normal during cruise in a King Air 300?

At approx FL200 in our King Air 300 we experience a vibration and notice the torque drop for both engines. The torque stays about 10% lower than normal in cruise. The vibration is intermittent and ...
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5answers
6k views

Do aircraft cabins have suspension?

On cars, we have 'shock absorber' suspension that decouples the passengers and loads from the road vibrations, bumps etc. On planes do we have any form of suspension that decouples the passengers &...
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2answers
167 views

Main structural (and any other) impact of hard landing

I was reading this question related to the parts suffering the most G forces. Reflecting about that question I question myself about hard landing, which is not a normal operation. So, my especific ...
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3answers
190 views

Is there any alternative to isolating the vibration of an ultralight engine other than using engine mounts?

Is there any alternative to isolating the vibration of an ultralight engine other than using engine mounts?
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2answers
702 views

How is vibration isolation achieved in helicopters?

In many helicopters, they say they have reduced the vibrations significantly, but how is this isolation being achieved?
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1answer
4k views

What is the range of frequencies of vibration in a helicopter due to the main rotor alone?

Vibration in helicopter can be caused by many different reasons. I am interested to know what is the range of frequencies of vibration due to the main rotor alone? I understand that it would depend ...