Major Engine Manufacturers in Civil Aviation and Recent Developments in New Generation Engine Production

What are the Expectations from New Generation Engines in Civil Aviation?

In all engine designs envisaged to be used in civil aviation in the future, it is desired to meet the expectations for low fuel consumption, low maintenance-repair and operating costs, and environmental factors, in short, engine efficiency. The civil aviation world is eager to use the new generation propulsion vehicles produced for autonomous systems. The world's leading engine manufacturers are striving to burn less fuel, reduce carbon dioxide (CO₂) emissions into the atmosphere and develop environmentally friendly aircraft engines that produce less noise. They are introducing new technologies for this purpose. Engine companies continue their quest to increase the efficiency of aircraft engines while at the same time developing electric and hybrid propulsion systems. 

Airbus, for example, announced in September 2020 that it aims to produce a hydrogen-powered aircraft by 2035. Considering that a large number of unmanned aerial vehicles (UAVs) and aircraft to be developed to meet the need for urban air mobility (UAM) are starting to fly in densely populated areas, the aero-acoustics of these engines is also expected to be a design focus. Propulsion research and development envisages the use of new technologies and an even shorter engine development cycle than today. At the same time, efforts are underway to reduce the weight of new engines, improve engine performance, reduce engine fuel consumption, improve reliability, reduce emissions and noise, extend engine life and reduce maintenance requirements. The work being carried out in the field of engines, the most important and most expensive part of the aircraft, is aimed to shape the green transformation of the airline industry. In order to meet the expectations of global companies providing international airline transportation services, the world's four leading engine manufacturers (Pratt&Whitney, CFMI, General Electric, Rolls-Royce) are working on new models, developing different approaches according to their corporate cultures and know-how in the engine industry, and aiming to meet their customers with different solutions.

Pratt & Whitney

Pratt & Whitney is a company that, in addition to military aviation engines, has entered civil aviation with its PW1000G engines, most notably powering the Airbus A220 and A320neo family. Six different variants of this engine collectively make up the GTF family. Pratt & Whitney is currently investing around 10 billion dollars in turbofan gear technology and is looking to advance in this field. The GTF engine fans are designed by Pratt & Whitney to rotate much slower than the engine's other main components, the compressor and turbine. This allowed P&W to achieve a bypass ratio of 12:1, the highest in the aircraft engine industry. The turbofan gear design allows for double-digit reductions in fuel efficiency, noise and emissions. Pratt & Whitney claims that GTF's new designs with even higher bypass ratios will be the "architecture of the future". Pratt & Whitney is also working on a hybrid-electric turboprop engine demonstrator that De Havilland Canada will test on the Dash 8-100. Flight tests of this hybrid engine are expected to begin in 2024. The aim is to launch fully electric, hybrid-electric and hydrogen-powered engine variants. These new types of propulsion systems are initially intended to be used in regional passenger aircraft, and depending on the progress to be made, they will also be used in narrow and wide-body aircraft.

CFM International (CFMI)

The letters CFM do not stand for an acronym. CFM is a joint venture between GE Aviation and Safran. Its starting point is the CFM56 engine, a merger of the designation used by these two companies for their commercial engines. GE's CF6 engine and Snecma's M56 products are identified as CFM56 under a single brand. In addition to being the manufacturer of the CFM56, the best-selling aircraft engine of all time, CFM International is now on track to become the manufacturer of the LEAP (Leading Edge Aviation Propulsion) engine, a pioneering high-bypass turbofan. LEAP engines are already being used in flights and are expected to be widely available soon. The use of ceramic matrix composites (CMC) material in LEAP engines and the introduction of fuel nozzles produced with 3D technique as a new technology are remarkable. So far, 35,500 LEAP engines have been ordered. This makes the LEAP engine the second most ordered jet engine in the world after the CFM56, which has been in service for 44 years. Previously, CFM announced that it aims to close the year with the production of 2,000 LEAP engines in 2023. There is information that the famous engine manufacturer CFM is about to achieve this goal.

Meanwhile, CFM announced a new engine study with the theme of 'the future of aviation' in June 2021. CFM talked about a step that we can call a revolutionary innovation for sustainable engine production. The RISE (Revolutionary Innovation for Sustainable Engines) program aims to develop a new generation CFM engine by the mid-2030s. This program aims to reduce fuel consumption and carbon emissions by at least 20 percent with the new engine, which will be developed according to an open fan architecture for the first time in the world, and is also expected to be one hundred percent compatible with the use of Sustainable Aviation Fuel (SAF) or hydrogen as fuel. CFM claims that the RISE program will be a real game changer.

GE Aviation

GE Aviation is a leading engine company in terms of engines used in civil aviation. It is capable of producing large turbofan engines. In fact, the GE90, which powers the Boeing 777 family, was the world's largest jet engine when it entered service in 1995. At the time, GE introduced composite fan blades, which it used for the first time in this engine. It was also the first engine to use FAA-approved 3-D printed parts. The gains from the GE90 engine were blended with newer technologies and then carried forward to the new engine variant, GEnx, which allows for approximately 15 percent more fuel efficiency. GEnx powers the Boeing 787 and 747-8 wide-body airplanes. This engine variant has earned a reputation as one of the best-selling, high-thrust jet engines in the company's history.

The GE9X, meanwhile, is GE's newest engine developed specifically for the Boeing 777X. The GE9X is an engine with dimensions larger than the fuselage of a Boeing 737. It is also more powerful than America's first manned space rocket. At 134,300 pounds of high thrust, the GE9X engine holds the record as the world's most powerful engine. In these engines, where the fan blades are made even thinner, this method increases aerodynamic efficiency, while the resulting lower fan radius ratio maximizes airflow. Thus, drag can also be kept to a minimum. Unlike the other variants, this engine variant uses a smaller number of fan blades. Instead of 38 fan blades used in CF6, 16 fan blades are used in GE9X engines. Thus, the GE9X has the most efficient fan mechanism, which improves the performance of its purple and allows for less fuel consumption. Around 65 ceramic composite materials (CMC) were used in the GE9X engine. The use of CMC material allows the weight of parts made of this material to be reduced by 70%. It also provides a twofold increase in durability compared to parts made from other materials. CMC is one-third the weight of steel. It can withstand temperatures as high as 2,400 degrees Fahrenheit, far beyond the melting point of many advanced metallic superalloys. Thus, CMC is a breakthrough in improving thermal efficiency in next-generation engines.

In GE9X engines developed using additive manufacturing technique, more than 300 engine parts are embedded in seven components produced by 3D printing. This makes it possible to reduce the overall weight of the engine. This engine is ten percent more fuel efficient than the GE90. The GE9X engine was granted FAA certification on September 25, 2020, registering the engine in terms of airworthiness and reliability. Also in November 2021, the engine successfully passed the dust extraction test. Boeing plans to use the GE9X engine on 777X aircraft starting from 2024. In this context, in February 2022, Qatar Airways ordered 50 of these engines in addition to the purchase of 50 Boeing 777-8 freighters, ensuring that it will be the first airline to use GE9X engine technology. The 777-8 Freighter is being optimized to use only the GE9X engine. At the same time, Singapore Airlines has ordered 22 more GE9X engines for its Boeing 777Xs, in addition to the 40 orders previously placed. In July 2022, Lufthansa announced the purchase of Boeing 777-8 Freighters with GE9X engines to develop its cargo fleet. Lufthansa also announced that it has ordered 14 GE9X engines for use on these aircraft. GE announced that it has received a total of 700 engine orders so far, amounting to $28 billion. 

GE is also working on MESTANG (More Electric Systems and Technologies for Aircraft in the Next Generation). In addition, fan blades to be produced from composite materials, heat-resistant light metal alloys, advanced cooling methods and additive manufacturing technologies are also included in the company's range of new technologies.

In order to meet these production targets and develop new technologies, GE Aviation has found it necessary to invest $4.3 billion in its US facilities and $1.1 billion in its overseas production facilities. According to GE; with the new engine facilities, it aims to realize the mass production of components to be produced with the use of advanced materials in shorter time and in larger numbers. 

Rolls-Royce

Rolls-Royce engines are used in Airbus and Boeing wide-body passenger/cargo aircraft. Rolls-Royce aims to offer 2-shaft and 3-shaft engine solutions in the engines it plans to produce in the future. These new architecture engines are expected to be improved with innovative technologies. In the meantime, Rolls-Royce has announced that it is focusing on the goal of building the world's largest jet engine. The first prototype of the new gigantic engine, dubbed the UltraFan demonstrator, which will have the largest fan diameter ever at 140 inches, is said to be in the assembly phase at the company's facility in Derby, England. The power transmission of this prototype engine reached 87,000 horsepower, a new record in this field. The first demonstrator engine, UF001, is expected to make its first run on 100 percent sustainable aviation fuel (SAF) by early 2024. The new engine, which will offer 25 percent fuel efficiency compared to previous Trent-type variants, is being produced with the long-term goal of powering the wide-body jets of the 2030s.

New Approaches in Engine Technology

Recent civil aviation engines have increased turbine inlet temperature, increased compressor pressure ratio, increased bypass ratio, improved fan and nacelle performance, reduced noise and emissions, and improved reliability. New engine technologies include engine-body integration, new and improved materials and material processing techniques, advances in turbomachinery technology, advances in combustion technology, and the use of greatly improved versions of Computational Fluid Dynamics (CFD) in engine design procedures. Carbon fiber winglets have enabled the development of highly efficient long-haul jets such as the Boeing 777 and Boeing 787 Dreamliner, where two engines are considered sufficient instead of four. In the coming years, new technologies such as "smart engines" and the use of magnetic bearings promise to open new doors that will change the course of development of engines for commercial aviation. Additive manufacturing is also expected to enable the use of lighter parts in engines, which can be produced cheaper and faster, reducing assembly costs and production time, as well as simplifying engine maintenance and increasing fuel economy.

Conclusion

Today's technological innovations have enabled us to reach a level of maturity that allows us to reduce emissions and noise in addition to fuel efficiency. The two most widely used aircraft in commercial aviation are the Boeing 737 and the Airbus A320. The new models of these two airplanes not only carry more passengers, but also burn 23 percent less fuel with their new engines. CFMI, Pratt & Whitney, General Electric and Rolls-Royce, the world's four leading engine manufacturers, are in a fierce race to develop engines that meet the expectations of commercial aviation companies and to make them available to their customers in a short time. This race is about to bring more advanced and environmentally friendly engines to the service of humanity. The production of new generation smart engines in the increasingly complex field of civil aviation is only possible with the great technological know-how of very few countries. While it seems possible for countries that are lagging behind to build the fuselage of an airplane, I believe that it is about to become a mission impossible for them to catch up with the trend in these advanced engines. Nevertheless, I still maintain my belief that an approach similar to the TR engine, which is targeted to be produced for the MMU Kaan, should start somewhere in civil aviation as soon as possible, albeit belatedly.