The first plane designed by Wrigth Brothers called Flyer used a propeller type engine, which had been used for many years until they were replaced by jet engines. Jet engines not only increased the aircraft speed, which was limited to 700 km/h with propeller types, they also provided flight comfort because they were quite and less vibratory. Jet engines have been dominated the market since 1950's and their designs have been improved greatly for the past 20 years with the invention of new material alloys, which can stand higher temperatures. Despite jet engine's success, a search for a new engine with better fuel economy has always continued.
With green energy becoming an important topic in the recent years, Propfan technology initially developed by NASA in 1980s has received a lot of attention and development funds. Propfan is a combination of propeller and jet engine technologies. Propfan is built almost identical to a jet engine, and it basically works with the same principle: extraction of energy from a flow of hot combustion gas. Generated energy is; however, used to power an exposed fan, similar to turboprop engines. In other words, thrust is generated by propellers placed outside the engine not by the exhaust jet. Propfan engines have
- the fuel efficiency advantages of propeller type engines, and
- the performance capability of commercial jet engines.
Recent tests of Propfans showed 30% less fuel consumption compared to jet engines. Tom Williams, executive vice president for programmes and former head of Airbus in the UK, believes that Propfans will be in service by 2025. They will first be used on short to mid range aircrafts. Williams said "Airlines are looking for technologies that will greatly reduce their fuel consumption, and Propfan technology is very likely to succeed."
0 comments:
Post a Comment