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The problem with diesels is that, for a given size, there is a fixed amount of power generated per cylinder. To increase power it is necessary to add cylinders but, when cylinders are added, the crankshaft has to be lengthened and after a very limited number of additions, the lengthened crankshaft begins to flex and vibrate all on its own.
The amplifying devices in audio and radio equipment are vulnerable to a variety of feedback problems, which can cause distinctive noise in the output. The term motorboating is applied to oscillations whose frequency is below the range of hearing, from 1 to 10 hertz , [ 3 ] so the individual oscillations are heard as pulses.
For urgent orders requiring rapid acceleration, the handle is moved three times so that the engine room bell is rung three times. This is called a "cavitate bell" because the rapid acceleration of the ship's propeller will cause the water around it to cavitate, causing a lot of noise and wear on the propellers. Such noise is undesirable during ...
The tach timer is usually used to schedule engine maintenance, although it is just an approximation of "Time in service" which is used to time and schedule aircraft maintenance. Time in service is defined in 14 CFR 1.1 [ 2 ] as the actual time in the air, whereas tach time measures engine revolutions, which would still count time on the ground ...
Hogging is the stress a ship's hull or keel experiences that causes the center or the keel to bend upward. Sagging is the stress a ship's hull or keel is placed under when a wave is the same length as the ship and the ship is in the trough of two waves.
A circle of death can be initiated if the boat operator releases the steering mechanism while the boat is still powered, which means the propeller is still turning. The force of the rotating propeller blades incurs a force known as steering torque , causing the motor itself, which is mounted on a swivel jointed mechanism, to turn sharply into ...
Wave-making resistance is a form of drag that affects surface watercraft, such as boats and ships, and reflects the energy required to push the water out of the way of the hull. The hull of a moving watercraft creates waves (a wake ) which carry energy away and resist the motion of the watercraft.
This solution focuses on the materials that marine propellers are created from which is a direct factor in cavitation. While redesigning propellers would only garner an extra one or two percent efficiency in operation, changing the materials a propeller is made from has greater effects. [ 3 ]