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An axial fan is a type of fan that causes gas to flow through it in an axial direction, parallel to the shaft about which the blades rotate. The flow is axial at entry and exit. The fan is designed to produce a pressure difference, and hence force, to cause a flow through the fan. Factors which determine the performance of the fan include the ...
A household electric fan A large cylindrical fan. A fan is a powered machine that creates airflow. A fan consists of rotating vanes or blades, generally made of wood, plastic, or metal, which act on the air. The rotating assembly of blades and hub is known as an impeller, rotor, or runner. Usually, it is contained within some form of housing ...
The GE Passport is a high bypass ratio turbofan. The engine is a twin-spool, axial-flow turbofan with a high bypass ratio of 5.6:1 and an overall pressure ratio of 45:1. The front fan is attached to the three-stage low-pressure compressor; the 23:1 pressure ratio 10-stage high-pressure compressor includes five blisk stages for weight reduction.
The high-bypass turbofan engines used on many modern airliners is an example of a very successful and popular use of ducted fan design. The duct increases thrust efficiency by up to 90% in most cases [citation needed], in comparison to a similar-sized propeller in free air. Ducted fans are quieter, and offer good opportunities for thrust vectoring.
The second family is the 100 inch (2.5 m) fan engine developed specifically for the Airbus A330 twinjet, and the third family has a diameter of 112-inch (2.8 m) designed to power Boeing 777. The Pratt & Whitney F119 and its derivative, the F135, power the United States Air Force's F-22 Raptor and the international F-35 Lightning II, respectively.
A commercial fan delivering air at 20 miles per hour (mph) requires about 64 times as much power as a similar sized fan delivering air at five mph. [8] Airspeed, combined with fan "effectiveness," means that when the objective is to cool people or animals, very large, low-speed commercial fans are more efficient and effective than small high ...
The two are related by the propulsive efficiency, [66] a measure of the energy wasted as a result of producing a force (ie thrust) in a fluid by increasing the speed (ie momentum) of the fluid. Dry engine ratings/ throttle lever positions below afterburning selection EGT exhaust gas temperature EPR engine pressure ratio Fan turbofan LP ...
Fan disks must withstand the centrifugal force of the attached fan blades. Because of their size and weight, a failed fan disk can severely damage an aircraft, as happened with United Airlines Flight 232 in 1989. [4] While operating there is increased aerodynamic loading on the fan disk while the fan blade tips are traveling faster than sound. [5]