Periodic Reporting for period 2 - LiTRAS (Linear Innovative Thrust Reverser Actuator System)
Berichtszeitraum: 2022-03-01 bis 2023-02-28
In order to meet the challenges of transport, the European aeronautics industry must continue to innovate so that it maintains a competitive edge over traditional and emerging competitors. Societal needs require products to be more environmentally friendly, e.g. by reducing fuel consumption, gas and noise emissions. These requirements demand new technologies from all sectors, and from aerospace community in particular.
In this context, a way to increase the efficiency of aircraft propulsion is the development of UHBR (Ultra-high bypass ratio) turbofan engines, which reduce the fuel required. However, these new engine concepts reduce the space available for other systems, one of which is the thrust reverser (TR). Basically, this is responsible during landing for opening the doors of the nacelle where the propulsion engine is installed in order to assist the braking of the aircraft. This system is usually driven by hydraulics actuators synchronized by mechanical means to allow the simultaneous opening of all the TR cowls and vanes of the aircraft engine. High temperature electromechanical rotary actuators can be used in place of hydraulics, but the actuator complexity is increased since it is equipped with several additional components like at least an electrical motor, a gearbox and a ball-screw.
The aim of the LiTRAS project is to replace traditional TR actuators with equipment based on linear motors to eliminate additional mechanical components needed to transform rotational motion into linear movement and simplifies the architecture. The aim is to simplify the architecture, reduce the weight of the system and increase its efficiency without losing reliability.
This has required developing specific linear motors with extraordinary thrust force density of 1.5 MN/m3 to actuate TR when dealing with demanding high-load emergency situations. The use of these actuators also means that other components of the TR will have to be redesigned, such as gate sliders, the blocking subsystem that prevents gates from opening accidentally, and the manual aperture of said gates when system maintenance operations must be performed. All according to strict operational and space requirements.
The main benefits of this application for the aeronautic industry will be (1) reducing the motors’ weight, (2) increasing their efficiency getting more efficient aircrafts, (3) contributing to the reduction of the development time of the future engine architectures by 10% and (4) more safety, because all these improvements increase reliability.
The LiTRAS project is set to be a compact, safe, reliable and easy to operate solution for the coming aeronautic industry.
In this context, a way to increase the efficiency of aircraft propulsion is the development of UHBR (Ultra-high bypass ratio) turbofan engines, which reduce the fuel required. However, these new engine concepts reduce the space available for other systems, one of which is the thrust reverser (TR). Basically, this is responsible during landing for opening the doors of the nacelle where the propulsion engine is installed in order to assist the braking of the aircraft. This system is usually driven by hydraulics actuators synchronized by mechanical means to allow the simultaneous opening of all the TR cowls and vanes of the aircraft engine. High temperature electromechanical rotary actuators can be used in place of hydraulics, but the actuator complexity is increased since it is equipped with several additional components like at least an electrical motor, a gearbox and a ball-screw.
The aim of the LiTRAS project is to replace traditional TR actuators with equipment based on linear motors to eliminate additional mechanical components needed to transform rotational motion into linear movement and simplifies the architecture. The aim is to simplify the architecture, reduce the weight of the system and increase its efficiency without losing reliability.
This has required developing specific linear motors with extraordinary thrust force density of 1.5 MN/m3 to actuate TR when dealing with demanding high-load emergency situations. The use of these actuators also means that other components of the TR will have to be redesigned, such as gate sliders, the blocking subsystem that prevents gates from opening accidentally, and the manual aperture of said gates when system maintenance operations must be performed. All according to strict operational and space requirements.
The main benefits of this application for the aeronautic industry will be (1) reducing the motors’ weight, (2) increasing their efficiency getting more efficient aircrafts, (3) contributing to the reduction of the development time of the future engine architectures by 10% and (4) more safety, because all these improvements increase reliability.
The LiTRAS project is set to be a compact, safe, reliable and easy to operate solution for the coming aeronautic industry.
The project began with the definition of specifications for the new linear TR actuator, and after the first 18 months the design of the prototype to be built and validated within the project has been completed. The main tasks carried out in that period were, basically:
- Define the specifications: analyse the specifications of the real application, identify those that can be met within the project timeframe, that aims reaching TRL4, and evaluate how to ensure that a future version to be used in real aircraft meets all the other specifications.
- Design the linear motor integrated into the actuator: analyse the state of the art of electric linear motors and identifying suitable motor types for this application; then carry out preliminary designs to further evaluate these types and select the candidate to be developed in the project; and finally, design the motor in detail and optimise it to meet the performance and integration requirements.
- Design the complete actuator: identify the necessary elements apart from the motor, include the systems for locking the mechanism and for its manual operation for maintenance work, and the motor guidance system; then carry out a preliminary design of these; and finally, their optimisation and detailed design.
After designing LiTRAS actuator, the next period of the Project has been devoted to manufacture a real scale prototype, and validate it through experimental tests in a test-bench applying the same force loads that would be in the real aircraft.
The main activities carried out in this period are, basically:
- Manufacture the parts, and purchase commercial elements. One of the most challenging tasks has been the design for manufacturing of the motor slider frame, because it is a very slender part and needs to be very flat in order to assure motor airgap uniformity all along its active length.
- Assemble the prototype. Particularly delicate is the assembly of the different parts because there is huge magnetic attraction between the magnets and the stators of the motor. A specific bench has been prepared to carry out the assembly.
- Prepare the test bench.
- Realize the experimental tests. Test results correlate well with the theoretical ones, thus the prototype is validated.
On the dissemination side several activities have been performed:
- Communication about LITRAS project on the partners' website and social networks (Twitter, LinkedIn).
- Two videos have been produced and made public through different channels (mainly by Youtube). One of the videos uses animated cartoons, and its aim is to present the ambition of the LITRAS project to the general public. The other video uses real images of the project and speeches by the project partners, and aims to convey more technical aspects of the project to an audience with more industrial or scientific knowledge.
- Scientific dissemination by presenting a technical paper about the linear motor on the 13th Coiltech 2022 conference (Italy, 2022, September 28-29) and submitting to the next R3ASC conference that will be held in September 2023 an abstract about the design and test of the LiTRAS actuator.
- Participation in aeronautics’ sector exhibition Feindef 2021 (Madrid, Spain), where CESA introduced LITRAS project with the professionals from industry, academia, etc. who visited CESA’s stand.
Identified Key Exploitable Results:
1. Linear innovative TR Actuator System (LiTRAS) concept.
2. Linear motor for high demanding environment.
- Define the specifications: analyse the specifications of the real application, identify those that can be met within the project timeframe, that aims reaching TRL4, and evaluate how to ensure that a future version to be used in real aircraft meets all the other specifications.
- Design the linear motor integrated into the actuator: analyse the state of the art of electric linear motors and identifying suitable motor types for this application; then carry out preliminary designs to further evaluate these types and select the candidate to be developed in the project; and finally, design the motor in detail and optimise it to meet the performance and integration requirements.
- Design the complete actuator: identify the necessary elements apart from the motor, include the systems for locking the mechanism and for its manual operation for maintenance work, and the motor guidance system; then carry out a preliminary design of these; and finally, their optimisation and detailed design.
After designing LiTRAS actuator, the next period of the Project has been devoted to manufacture a real scale prototype, and validate it through experimental tests in a test-bench applying the same force loads that would be in the real aircraft.
The main activities carried out in this period are, basically:
- Manufacture the parts, and purchase commercial elements. One of the most challenging tasks has been the design for manufacturing of the motor slider frame, because it is a very slender part and needs to be very flat in order to assure motor airgap uniformity all along its active length.
- Assemble the prototype. Particularly delicate is the assembly of the different parts because there is huge magnetic attraction between the magnets and the stators of the motor. A specific bench has been prepared to carry out the assembly.
- Prepare the test bench.
- Realize the experimental tests. Test results correlate well with the theoretical ones, thus the prototype is validated.
On the dissemination side several activities have been performed:
- Communication about LITRAS project on the partners' website and social networks (Twitter, LinkedIn).
- Two videos have been produced and made public through different channels (mainly by Youtube). One of the videos uses animated cartoons, and its aim is to present the ambition of the LITRAS project to the general public. The other video uses real images of the project and speeches by the project partners, and aims to convey more technical aspects of the project to an audience with more industrial or scientific knowledge.
- Scientific dissemination by presenting a technical paper about the linear motor on the 13th Coiltech 2022 conference (Italy, 2022, September 28-29) and submitting to the next R3ASC conference that will be held in September 2023 an abstract about the design and test of the LiTRAS actuator.
- Participation in aeronautics’ sector exhibition Feindef 2021 (Madrid, Spain), where CESA introduced LITRAS project with the professionals from industry, academia, etc. who visited CESA’s stand.
Identified Key Exploitable Results:
1. Linear innovative TR Actuator System (LiTRAS) concept.
2. Linear motor for high demanding environment.
LiTRAS represents a novel TR actuation technology development up to TRL4, with high potential to contribute, once higher maturity level is reached, to an important reduction of architectural complexity and manufacturing/maintenance cost of future aerospace powerplant systems. At the end, LiTRAS actuators will provide a solution with much less components and fluids than hydraulic systems and rotary EMA architectures, so they have significant advantages:
1. Improved values of safety and reliability because it is jamming-free, and there is lower failure probability due to having much less components.
2. Lower maintainability because it doesn’t need relubrication, and almost no part is subjected to mechanical wear.
3. Environmentally more friendly because it can be integrated in the limited space of modern UHBR engines which consume less fuel and have lower emissions.
LiTRAS project is expected to improve European capability in electro-mechanical linear motion technology applied to the aerospace powerplant environment.
It also creates the basis for a future improvement of European capability in linear sensor technology for aerospace harsh environment.
1. Improved values of safety and reliability because it is jamming-free, and there is lower failure probability due to having much less components.
2. Lower maintainability because it doesn’t need relubrication, and almost no part is subjected to mechanical wear.
3. Environmentally more friendly because it can be integrated in the limited space of modern UHBR engines which consume less fuel and have lower emissions.
LiTRAS project is expected to improve European capability in electro-mechanical linear motion technology applied to the aerospace powerplant environment.
It also creates the basis for a future improvement of European capability in linear sensor technology for aerospace harsh environment.