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Technical Paper

Reconfigurable Jig Tooling and In-Process Metrology for High Accuracy Prototype Compound Helicopter Wing Assembly

2019-09-16
2019-01-1877
This paper documents the potential use of reconfigurable reusable jig tooling based on the box-joint system for use in the assembly of a prototype compound helicopter wing. Due to the aircraft configuration the wing design is pinned at both ends and therefore requires a higher degree of accuracy (typically 0.2mm), over the 4m length, than conventional wings. In this paper the cost benefit of reusable tooling in a low volume prototype scenario is examined followed by the design of the jig and location features to enable accurate build and metrology documentation. A prototype 4m test jig comprising of commercially available components and bespoke machined ‘pick-ups’ is presented here. Hardware and measurement process cost modelling is documented along with results for the positional and hinge-line concentricity setting accuracy that was achieved using a laser tracking system.
Technical Paper

Advanced Assembly Solutions for the Airbus RACER Joined-Wing Configuration

2019-09-16
2019-01-1884
The Rapid And Cost Effective Rotorcraft (RACER) is being developed by Airbus Helicopters (ABH) to demonstrate a new Vertical Take-Off and Landing configuration to fill the mobility gap between conventional helicopters and aeroplanes. RACER is a compound rotorcraft featuring wings and multiple rotors. The wing arrangement suggested by ABH is defined as a staggered bi-plane joined configuration with an upper and a lower straight wing, either side of the fuselage, connected at their outboard extent to form a triangular structure. The ASTRAL consortium, consisting of the University of Nottingham and GE Aviation Systems, are responsible for the design, manufacture and assembly of the wings. Producing an optimised strategy to assemble a joined-wing configuration for a passenger carrying rotorcraft is challenging and novel. The objective of this work concerns all aspects of assembling the joined-wing structure.
Technical Paper

Low cost, fireproof, and light aircraft interior

2019-09-16
2019-01-1857
Low cost, fireproof, and light aircraft interior Fire is a dramatic issue in aircraft nowadays, especially with composite air crafts. An additional issue is the dangerous use of flammable Li-Ion batteries in a lot of appliances. we propose in order to avoid dramas to produce aircraft interiors, fire doors, cargo bay walls, as well than cargo container able to contain a fire inside them, with our ceramic composite called TOUGHCERAM ®. We have developed a low-cost, ceramic, damage tolerant, this ceramic is flexible between minus 100°C and plus 350°C. TOUGHCERAM ® poly-crystalize between 60°C and 110°C and can be reinforced with fibbers like carbon or basalt one. TOUGHCERAM ® survive 90 minutes to a propane 1900°C torches. TOUGHCERAM ® does not burn, nor smoke. In this paper we will explain how it is possible to develop a fully mineral ceramic offering such unique mechanical and fire properties.
Technical Paper

Intelligent Real Time Inspection of Rivet Quality supported by Human-Robot-Collaboration

2019-09-16
2019-01-1886
Aircraft production is facing various technical challenges, such as large product dimensions, complex joining processes and the organization of assembly tasks. Meeting the requirements that come with large dimensions, low tolerances and small batch sizes, in combination with complex joining processes, automation and labour-intensive inspection task, is often difficult to achieve in an economically viable way. ZeMA believes that a semi-automated approach is the most effective for optimizing aircraft section assembly. An effective optimization of aircraft production can be achieved with a semi-automated riveting process for solid rivets using Human-Robot-Collaboration in combination with an intuitive Human-Machine-Interaction operating concept. While using dynamic task sharing between human and robot based on their skills, and considering ergonomics, the determined ideal solution involves placing a robot inside the section barrel.
Technical Paper

Electromagnetic Characteristic Comparison of Superconducting Synchronous Motors for Electric Aircraft Propulsion Systems

2019-09-16
2019-01-1912
Aircraft service has been increasing today and it also results in the increase of the greenhouse gas emission. To solve this problem, the electric aircraft propulsion system is the key solutions to realize the clean and high efficiency aircraft, while demanding higher output density motors. So far, though 5 kW/kg is realized with permanent magnet type synchronous motors, the electric aircraft for over 100 passengers demands motors with 16 -20 kW/kg. Superconducting (S.C.) technology is one of the effective candidates for higher output density motors. In comparison with copper wires, the S.C. wires have higher current density at less than –200 ℃. And we can make a lighter weight coil with the S.C. wires. So far, many groups have been studying the S.C. motors over 16 kW/kg. Generally, there are two kinds of S.C motors. One is the S.C. motors made of the S.C. field coils and copper armature windings. The other is the fully S.C. motors using S.C. field and armature windings.
Technical Paper

Compensating the Effects of Ice Crystal Icing on the Engine Performance by Control Methods

2019-09-16
2019-01-1862
Aircraft equipment is operated in a wide range of external conditions, which, with a certain combination of environmental parameters, can lead to icing of the engine internal elements. Due to icing, the engine components performance change what leads to decrease in thrust, gas dynamic stability, durability, etc. Safe aircraft operation and its desired performance may be lost as a result of such external influence. Therefore, it is relevant to study the possibilities of reducing the icing effect with the help of a special engine control. The focus of this paper is to determine control methods of an aircraft gas turbine engine addressing this problem. The object of the study is a modern commercial turbofan with a bypass ratio of about 9. In this paper analysis of the effect of ice crystal icing on the engine components performance is conducted.
Technical Paper

C919 Trailing Edge Assembly Interchangeable Tooling

2019-09-16
2019-01-1880
Traditional Trailing Edge (TE) assembly that utilise fixtures for accurate positioning of aircraft (a/c) parts do not allow for removal of specific tooling from the fixtures to travel with the TE, post assembly. Instead, the tooling that positions all the primary a/c assembly datums generally utilise precision pins of various sizes that index and clamp the a/c ribs. Often it is difficult to remove the pins post assembly before the spar can be taken out of the fixture. Use of hammers is common place to hit pins out of holes which is less than ideal considering the a/c parts can be fragile and the tooling is precision set. Also, the Main Assembly Fixture (MAJ) that will receive the TE will inevitably need to relocate some if not all the primary a/c ribs and therefore will most likely be subject to some amount of persuasion.
Technical Paper

Hypersonic flow simulation towards space propulsion geometries

2019-09-16
2019-01-1873
With the actual tendency of space exploration, hypersonic flight have gain a significant relevance, taking the attention of many researchers over the world. This work aims to present a numerical tool to solve hypersonic gas dynamic flows for space propulsion geometries. This will be done by validating the code using two well-known hypersonic test cases, the double cone and the hollow cylinder flare. These test cases are part of NATO Research and Technology Organization Working Group 10 validation of hypersonic flight for laminar viscous-inviscid interactions. During the validation process several important flow features of hypersonic flow are captured and compared with available CFD and numerical data. Special attention is taken to the phenomenon of vibrational excitation of the molecules. Different vibrational non-equilibrium models are used and compared with the available data. The pressure and the heat flux along the surfaces are also analyzed.
Technical Paper

Analysis of a Coupling System of Aircraft Environmental Control and Fuel Tank Inerting Based on Membrane Separation

2019-09-16
2019-01-1895
This paper raises a coupling system of aircraft environmental control and fuel tank inerting based on membrane separation. The system applies a membrane dehumidifier to replace water vapor removal unit of heat regenerator, condenser and water separator, which is widely used in conventional aircraft environmental control system nowadays. Water vapor can travel across the membrane wall under its pressure difference without phase change, so the dehumidification process consumes no cooling capacity and the cooling capacity of the system increases. This paper first compares the thermodynamic properties of environmental control system based on membrane dehumidification and the environmental control system based on condensation. The results show that the membrane dehumidification system has bigger cooling capacity and lighter weight.
Technical Paper

Analytical Model for Calibration Results performances enhancement, resulting in automated prescription for equipments

2019-09-16
2019-01-1878
The current aeronautical manufacturing sector is characterized by the high level of competence and the required requirement in its production processes, based on the objectives of profitability and safety (airworthiness). In recent years, there is a real revolution in the sector, where the most advanced tools for the organization and optimization of production are given priority, supported by the latest massively used techniques of automatic data collection. , their organized storage and their analytical classification. Metrology plays a key role in ensuring the quality and reliability of the information generated in these productive cycles. The provision of an analytical model of flexible measurement systems, capable and easily adaptable to the dynamics of the company, is presented as one of the pillars in which this new conception of production is based.
Technical Paper

Preliminary Design of Hydraulic and Pneumatic System Architectures for a Morphing Flight Control Structure

2019-09-16
2019-01-1916
Bionics in aeronautics has the potential to increase the performance and efficiency of aircraft significantly. Inspired by the wings of birds, morphing wing structures are extensively investigated over the last decades. The continuous adaption of the wings over a large scale of the flight envelope enables an optimization of the aerodynamic characteristics and, in this way, a reduction of the fuel consumption. Additionally, those structures could support or replace traditional flight control surfaces. Depending on the morphing technology, different systems may be suitable to actuate the morphing structure. An early inclusion of the system architecture concepts into the development of the morphing technology enables the design of an optimal system in compliance with all requirements. Therefore, this paper discusses the conceptual design of system architectures for a novel morphing wing structure that is used for flight control.
Technical Paper

Self-affinity of an Aircraft Pilot's Gaze Direction as a Marker of Visual Tunneling

2019-09-16
2019-01-1852
For the last few years, a great deal of interest has been paid to crew monitoring systems in order to address potential safety problems during a flight. They aim at detecting any degraded physiological and/or cognitive state of an aircraft pilot or crew, such as visual tunneling, also called inattentional blindness. Indeed, they might have a negative impact on the performance to pursue the mission with adequate flight safety levels. One of the usual approaches consists in using sensors to collect physiological signals which are then analyzed. Two main families exist to process the signals. The first one combines feature extraction and machine learning whereas the second is based on deep-learning approaches which require a large amount of labeled data. In this work, we focused on the first family.
Technical Paper

Numerical Analysis of a Cycloidal Rotor Under Diverse Operating Conditions and Altitudes

2019-09-16
2019-01-1872
The current paper deals with the numerical study of the downwash flowfield characteristics in a cycloidal rotor. In an aircraft equipped with this kind of thruster, the downwash flow plays significant role in different flight modes. The interaction of this downwash jet with ground in effective height levels is studied using CFD simulations. Several operating conditions like pitching oscillation angles, rotation speeds and height levels are all considered in this work. The results declare that close-ground operating states augments the efficiency of cyclorotor. The vertical and horizontal forces of a single blade is also analyzed in a complete cycloid in different operating conditions. A lead and lag in maximum and minimum extremes of force curves of a single blade cycloid is obtained while being subjected to different functional conditions.
Technical Paper

Landing Gear Integration into Aircraft Structure in Early Design Stage

2019-09-16
2019-01-1890
The demanded development towards various emission reduction goals set up by several institutions forces the aerospace industry to think about new technologies and alternative aircraft configurations. With these alternative aircraft concepts, the landing gear layout is also affected. Turbofan engines with very high bypass ratios could increase the diameter of the nacelles extensively. In this case, mounting the engines above the wing could be a possible arrangement to avoid an exceedingly long landing gear. Thus, the landing gear could be shortened and eventually mounted at the fuselage instead of the wings. Other technologies such as high aspect ratio wings have an influence on the landing gear integration as well. To assess the difference, especially in weight, between the conventional landing gear configuration and alternative layouts a method is developed based on preliminary structural designs of the different aircraft components, namely landing gear, wing and fuselage.
Technical Paper

Advanced Exergy Analysis of an Air Craft Gas Turbine Engine at Different Power Loading Operations.

2019-09-16
2019-01-1863
The innovations in aircraft propulsion have been identified as the key parameter towards the progress in transportation. Continuous advancement in the performance and efficiency of propulsion has enabled aircraft to travel over larger distances with higher speed. Aviation is also responsible for approximately 2% of total greenhouse gases emission and is expected to grow around 3% by 2050. The present study aims to use the exergetic analysis of a turboprop engine which should be helpful in designing of such engines and also helps these engine users to regulate and select the operation modes. A gas turbine with film air cooling of turbine blades has been proposed to be the turboprop engine. The engine is analyzed on exergy point of view at different power loading operation modes and the performance is studied.
Technical Paper

The benefits of using Composite Bearings in Aircraft Shock Absorbers

2019-09-16
2019-01-1898
This paper will use actual examples from aircraft recently introduced into service, to describe the main advantages of changing from the currently used metallic bearings, to composite bearings. Abstract: The introduction of composite bearing in a recently introduced twin aisle aircraft has resulted in: • Weight saving, by replacing bronze bearings with plastic bearings • Lowering of the particle count in the shock absorber oil, (Reduced contamination with metal particles) leading to reduced wear on seals and bearings. Qualification testing showed that Composite Bearings are able to provide longer service life than bronze bearings.
Technical Paper

Simulation of aircraft assembly via ASRP software

2019-09-16
2019-01-1887
ASRP (Assembly Simulation of Riveting Process) software is a special tool for modelling assembly process for large scale airframe parts. On the base of variation simulation, ASRP provides a convenient way to analyze, verify and optimize the arrangement of temporary fasteners. During the airframe assembly process certain criteria on the residual gap between parts must be fulfilled. The numerical approach realized in ASRP allows one to evaluate the quality of contact on every stage of the assembly process and solve verification and optimization problems for temporary fastener patterns. The paper is devoted to description of several specialized approaches that combine statistical analysis of measured data and numerical simulation using high-performance computing for optimization of fastener patterns, calculation of forces in fasteners needed to close initial gaps and identification of hazardous areas in junction regions.
Technical Paper

Design Approach for Secure Networks to introduce Data Analytics within the Aircraft Cabin

2019-09-16
2019-01-1853
In the past, aircraft network design did not demand for information security considerations. The aircraft systems were simple, obscure, proprietary and, most importantly for security, the systems have been either physically isolated or they have been connected by directed communication links. The union of the aircraft systems thus formed a federated network. These properties are in sharp contrast with today’s system designs, which rest upon platform-based solutions with shared resources being interconnected by a massively meshed and shared communication network. The resulting connectivity and the high number of interfaces require an in-depth security analysis as the systems also provide functions that are required for the safe operation of the aircraft. This network design evolution, however, resulted in an iterative and continuous adaption of existing network solutions as these have not been developed from scratch.
Technical Paper

Improving competitiveness of Additive Manufacturing Aerospace serial parts

2019-09-16
2019-01-1900
The interest of selective laser melting technology for aerospace parts is very high due to their high complexity and their freedom of design which allow functions integration. However, the competitiveness of Laser Beam Melting (LBM) machines for aerospace industry is limited by two major road blocks. On the one hand, basic parametric set sold with LBM machines are more oriented to historical qualification than productivity rates. For instance, the ongoing qualification on EOS M290 by AIRBUS COMMERCIAL AIRCRAFT only enables us to produce a hundred pieces per machine per year. On the other hand, wasted times between two consecutive manufacturing batches are significant and are impacting the yearly output of the machines. The present project focuses on two activities, focusing on the largest available machines, XLINE2000R and M400, in order to maximize the amount of pieces per build.
Technical Paper

The Szorenyi Three-Chamber Rotary Engine concept

2019-09-09
2019-24-0168
Currently automotive engines are reciprocating or Wankel rotary engine types. Reciprocating engines are bulky, heavy and complex, mainly due to the intake and exhaust valves and their associated cam-­‐train. Wankel engines are rev limited due to the large eccentric load on the crankshaft, and have poor sealing of the apex seals leading to poor economy and undesirable emission gases. The Rotary Engine Development Agency (REDA) has designed a three­‐chamber rotary internal combustion engine concept using its patented Szorenyi Curve. It is an evolution of the four chamber engine design which was the subject of SAE Technical Paper 2017-­‐01-­‐2413 and SAE publication ‘So You Want to Design Engines: UAV Propulsion Systems’. This paper on the three­‐chamber engine concept includes an analysis of the major issues affecting the Wankel engine.
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