Advantages
- By reducing propeller blade tip losses, the ducted fan is more efficient in producing thrust than a conventional propeller, especially at low speed and high static thrust level (airships, hovercrafts).
- By sizing the ductwork appropriately, the designer can adjust the air velocity through the fan to allow it to operate more efficiently at higher air speeds than a propeller would.
- For the same static thrust, a ducted fan has a smaller diameter than a free propeller, allowing smaller gear.
- Ducted fans are quieter than propellers: they shield the blade noise, and reduce the tip speed and intensity of the tip vortices both of which contribute to noise production.
- Ducted fans can allow for a limited amount of thrust vectoring, something normal propellers are not well suited for. This allows them to be used instead of tiltrotors in some applications.
- Ducted fans offer enhanced safety on the ground.
Read more about this topic: Ducted Fan
Famous quotes containing the word advantages:
“Can you conceive what it is to native-born American women citizens, accustomed to the advantages of our schools, our churches and the mingling of our social life, to ask over and over again for so simple a thing as that “we, the people,” should mean women as well as men; that our Constitution should mean exactly what it says?”
—Mary F. Eastman, U.S. suffragist. As quoted in History of Woman Suffrage, vol. 4 ch. 5, by Susan B. Anthony and Ida Husted Harper (1902)
“A woman might claim to retain some of the child’s faculties, although very limited and defused, simply because she has not been encouraged to learn methods of thought and develop a disciplined mind. As long as education remains largely induction ignorance will retain these advantages over learning and it is time that women impudently put them to work.”
—Germaine Greer (b. 1939)
“To say that a man is your Friend, means commonly no more than this, that he is not your enemy. Most contemplate only what would be the accidental and trifling advantages of Friendship, as that the Friend can assist in time of need by his substance, or his influence, or his counsel.... Even the utmost goodwill and harmony and practical kindness are not sufficient for Friendship, for Friends do not live in harmony merely, as some say, but in melody.”
—Henry David Thoreau (1817–1862)