Open rotor motors, which have the potential to contribute significantly to reducing emission rates thanks to their fuel efficiency, promise a meaningful change for the aviation industry.
The aviation sector is one of the leading players that contribute to climate change negatively. Serious studies have been carried out for a long time to reduce the negative contribution of passenger aircraft used in the civil aviation sector in terms of both fuel consumption and emission rates. One of these works is propfan or “Open Rotor” motor technology as it is preferred today.
It is possible to express the architecture, which is called open rotor, which consists of two rows of open blades rotating in opposite directions and because they are also open, as a mixture of turboprop and turbofan engines in the simplest form. The architecture, which can be compared to a turbofan engine in terms of speed and performance and to a turboprop engine in terms of fuel economy, promises fuel savings of close to 30%.
The main structure of open rotor motors is the same as jet. In the system operating with jet engine logic, the cold air flow, which constitutes a large part of the impulse, comes out at a higher rate because the blades are exposed. This means a much more efficient engine. The only reason why pals are kept outside, and not in the nacelle (the enclosed part of the wing of an airplane that contains the engines) like conventional jet engines, is not just to provide a higher rate of airflow.
Another important advantage of the engines that survived the Nacelle is the lighter aircraft. In this way, engines that can be enlarged without creating additional load on the plane can become more efficient as they will breathe much more cold air. Open rotors, which are already in the design phase, are at least twice the size of existing motors.
Unfortunately, these engines, which have been under development since the 1980s, have not yet come out commercially. Safran, the multinational aircraft and rocket engine manufacturer based in France, making one of the most serious halves in this field, was able to show the demo version of the technology in 2017. According to the company, we still need time to see a product working in a real world environment.
Another issue that can be written as a minus to the current state of open rotors is the noise problem they have. Open rotors, which work much louder than a standard turbofan engine, may not be very suitable for passenger aircraft in their current form.
Companies such as US General Electric and Pratt & Whitney are also seriously investing in open rotor technology. Technology is likely to be implemented much faster nowadays with the pluses brought by three-dimensional printing methods. Let’s see how soon and to what extent the aviation sector will reduce its negative contributions to climate change thanks to the developing technology.