Search results
Results From The WOW.Com Content Network
A propeller that turns clockwise to produce forward thrust, when viewed from aft, is called right-handed. One that turns anticlockwise is said to be left-handed. Larger vessels often have twin screws to reduce heeling torque , counter-rotating propellers , the starboard screw is usually right-handed and the port left-handed, this is called ...
When the propeller slowed, the RPM would decrease enough for the spring to push the weights back in, realigning the propeller to the shallower pitch. Small, modern engines with a constant speed unit (CSU), such as the Rotax 912 , may use either the conventional hydraulic method or an electrical pitch control mechanism.
The propellers on some aircraft can operate with a negative blade pitch angle, and thus reverse the thrust from the propeller. This is known as Beta Pitch. Reverse thrust is used to help slow the aircraft after landing and is particularly advantageous when landing on a wet runway as wheel braking suffers reduced effectiveness.
A Mark 46 Mod 5A torpedo is inspected aboard a destroyer in April 2005. Contra-rotating propellers have benefits when providing thrust in marine applications. Contra-rotating propellers are used on torpedoes due to the natural torque compensation and are also used in some motor boats.
When most of the blade surface is covered by cavitation, the pressure difference between the pressure side and suction side of the blade drops considerably, as does the thrust produced by the propeller. This condition is called "thrust breakdown". Operating the propeller under these conditions wastes energy, generates considerable noise, and as ...
A toroidal propeller is a type of propeller that is ring-shaped with each blade forming a closed loop. The propellers are significantly quieter at audible frequency ranges, between 20 Hz and 20 kHz, while generating comparable thrust to traditional propellers. In practice, toroidal propellers reduce noise pollution in both aviation and maritime ...
The dynamometer measures the thrust and torque of the propeller. The propeller shaft extends a sufficient length forward from the boat to ensure that the flow around the propeller is not disturbed by the boat. The test is conducted by towing the open water boat at a steady speed while running the propeller at a constant revolution rate.
The propellers on a wing rotate in opposite directions to each other: the propellers rotate from the top of the arc downward toward each other. If both engines on a wing are operative, the shift of the thrust vector with increasing angle of attack is always towards the other engine on the same wing. The effect is that the resultant thrust ...