Propellers
A propeller converts through helical motion the energy supplied by a power source into thrust, a force that moves a vehicle forward in a fluid medium. They are used primarily for marine and aerial propulsion, but they are found on other technologies such as hovercraft and wind turbines as well. Propellers, which are essentially a series of twisted wings, or blades, connected to a central hub, are efficient energy transmission devices for those applications. The blades strike the air or water at a certain angle, called the pitch, and create an area of low pressure in front of the propeller. As a result, the blades generate thrust through either fluid or aerodynamic means by pushing forward through the low-pressure area. Slip, or the energy lost as the propeller rotates, offsets the full output of thrust. The effectiveness of the propeller is measured by propulsive efficiency, the ratio of engine power to the actual thrust produced minus slip, during one complete revolution of the propeller. Because this process resembles the twisting movement of a carpenter's screw as it advances through wood, marine propellers are often called "screws" and aerial propellers are called "airscrews."
There exists a wide range of propellers for different applications.
This page contains 201 words.
Propellers article
Read the rest of this article.
This article contains 2,292 words
(approx. 8 pages at 300 words per page).
Order our Propeller Article
