What is the purpose of an Unducted fan system?

The Unducted Fan (UDF) engine is an innovative aircraft engine concept based on an ungeared, counterrotating, unducted, ultra-high-bypass turbofan configuration. This engine is being developed to provide a high thrust-to-weight ratio power plant with exceptional fuel efficiency for subsonic aircraft application.

What happened to the UDF engine?

But what sparked the interest in developing a fuel efficient engine and aircraft became the demise of the UDF and the 7J7. The end of the oil embargo led to cheaper fuel prices. The 737 continued to be a workhorse for short to mid-range flights and the Airbus 320 offered even better performance.

How do propfan engines work?

You can think of the contemporary propfan as a turboprop that has two high rpm contra-rotating propellers or fans with six or more highly swept fan blades each. These fans are driven by a turbine engine through a reduction gear or a low-speed free turbine.

Who invented the turbofan?

Frank Whittle
Hans von Ohain
Jet engine/Inventors

How is an Unducted propfan different from the turboprop vs turbofan engine?

A propfan, also called an open rotor engine, or unducted fan (as opposed to a ducted fan), is a type of aircraft engine related in concept to both the turboprop and turbofan, but distinct from both. The design is intended to offer the speed and performance of a turbofan, with the fuel economy of a turboprop.

What happened to the GE36?

The GE36 was developed by General Electric Aircraft Engines, with its CFM International equal partner Snecma taking a 35 percent share of development. Development was cancelled in 1989.

What’s the difference between a propfan and a turboprop?

Are turboprops more efficient than turbofans?

In fact, turboprop engines are also more efficient than turbofan engines, but aircraft speeds using turboprop engines are typically lower than those of turbofan engines.

Which is better turbofan or turbojet?

Low-bypass-ratio turbofans are more fuel efficient than the basic turbojet. A turbofan generates more thrust for nearly an equal amount of fuel used by the core because the fuel flow rate is changed by slightly when adding the fan. As a result, the turbofan offers high fuel efficiency.