A fan disk is the central hub of a fan in a

turbofan The turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft engine, aircraft propulsion. The word "turbofan" is a portmanteau of "turbine" and "fan": the ''turbo'' portion refers to a gas turbine engine which ac ...

engine. Fan blades are attached to the fan disk, which is rotated by a shaft driven by a

gas turbine A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directi ...

. In modern passenger aircraft, most of the propulsive thrust comes from fans, which are driven by gas turbines. A single stage fan was developed to produce high thrust and act as a multi-bladed propeller. Fan disks are attached to a shaft that is driven by a multistage Low Pressure Turbine (LPT) to reduce mechanical stress. Air enters the front of an engine, where a fan increases the pressure by rotating within a duct. Most of the pressurized air is exhausted through the rear of the engine, where it expands and its velocity increases. Fan disks are large and heavy. The one shown in the photo is over 31 inches (1.2 m) in diameter, and rotates up to 3800

rotations per minute Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...

(RPM). 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 United Airlines Flight 232 was a regularly scheduled United Airlines flight from Stapleton International Airport in Denver to O'Hare International Airport in Chicago, continuing to Philadelphia International Airport. On July 19, 1989, the DC ...

in 1989. While operating there is increased aerodynamic loading on the fan disk while the fan blade tips are traveling faster than sound. A fan blade weighing 15-lbs can experience upwards of 60 tons of centrifugal force. Fan disks are usually made of a

titanium alloy Titanium alloys are alloys that contain a mixture of titanium and other chemical elements. Such alloys have very high tensile strength and toughness (even at extreme temperatures). They are light in weight, have extraordinary corrosion resistance a ...

, which is strong, light weight, and resistant to corrosion.

References

Muhammad Adnan , Liu Shujiel; FEA Analysis and Fatigue Life Prediction of Aircraft Turbine Disk; North American Academic Research, 4(4) 10-19, Apr 2021, https://doi.org/10.5281/zenodo.4670446 Muhammad Adnan , Liu Shujiel; FEA Analysis and Fatigue Life Prediction of Aircraft Turbine Disk; North American Academic Research, 4(4) 10-19, Apr 2021, https://doi.org/10.5281/zenodo.4670446 Aircraft propulsion components {{Component-aircraft-stub

See also

References