Abstract: Vacuum assisted resin infusion (VARI) is a process applied to manufacture large structures of composite materials, such as aircraft wing and fuselage skins, but the process parameters are designed by experience or lots of experiments. In this paper, the filling process of VARI for composite fuselage skin was analyzed based on simulation and optimized location of resin inlet ports. Firstly, we made 3D model of fuselage skin and simulated impregnation process. Secondly, we determined the location and quantity of resin inlet ports based on simulation results. The simulations showed that it is advisable to reduce the filing time not only by adding the resin inlet quantity, but also choosing optimal locations.

Abstract: In this paper, a vertical drop test of a full composite fuselage section of a regional aircraft has been presented. This test was performed to investigate the structural response of a prototype of ...

Abstract: Modern trends in the development of military and civil aviation are aimed at the constant growth of cruising and limit flight speeds of promising aircraft. The largest aviation powers (Russia, the USA, the EU, China, Japan) have created supersonic passenger and military aircraft and are talking about creating hypersonic aircraft. The pace of development of industrial technologies requires a significant reduction in the development of aviation equipment, so the advanced military aircraft of the 5th generation (Su-57, F-22, J-20, F-35) were developed within 10-15 years, and the requirements to the terms of creation of advanced aircraft complexes currently is no more than 8 years. These facts require a significant optimization of the aircraft life cycle stages, in particular, a significant volume of the development stage. In this paper, we consider the process of multi-criteria optimization of aircraft parameters at the stage of development and initial coordination of the minimum aerodynamic drag head-end of the aircraft fuselage, and assess the impact of this optimization on the life cycle of the product.

Abstract: The current necessity of the scientific and industrial community, for reduction of aircraft maintenance cost and duration, prioritizes the need for development of innovative nondestructive techniques enabling fast and reliable defect detection on aircraft fuselage and wing skin parts. Herein, a new low-cost thermographic strategy, termed Pulsed Phase-Informed Lock-in Thermography, operating on the synergy of two independent, active infrared thermography techniques, is reported for the fast and quantitative assessment of superficial and subsurface damage in aircraft-grade composite materials. The two-step approach relies on the fast, initial qualitative assessment, by Pulsed Phase Thermography, of defect location and the identification of the optimal material-intrinsic frequency, over which lock-in thermography is subsequently applied for the quantification of the damage's dilatational characteristics. A state-of-the-art ultra-compact infrared thermography module envisioned to form part of a fully-automated autonomous nondestructive testing inspection solution for aircraft was conceived, developed, and tested on aircraft-grade composite specimens with impact damages induced at variable energy levels and on a full-scale aircraft fuselage skin composite panel. The latter task was performed in semi-automated mode with the infrared thermography module mounted on the prototype autonomous vortex robot platform. The timescale requirement for a full assessment of damage(s) within the sensor's field of view is of the order of 60 s which, in combination with the high precision of the methodology, unfolds unprecedented potential towards the reduction in duration and costs of tactical aircraft maintenance, optimization of efficiency and minimization of accidents.

Abstract: In this paper, measurements of the attenuation by the window and fuselage of an aircraft for Terahertz communications are presented. The measurements are performed at 300GHz using an ultra wide-band sub-mmWave channel sounder in a Boeing 737. They are subdivided into a characterization of perpendicular and oblique incidence, respectively, with regard to the azimuth angle. Before presenting the results, the different measurement setups are described. The results suggest a minimal attenuation of -11.01 dB by the window for perpendicular incidence whereas no specific angle dependency could be identified.

Abstract: The aviation industry faces the challenge of offering aircraft that are lighter, more economical, and safer. One of the solutions is to increase the use of composites. For these materials, adhesive...

Abstract: Continuous curvilinear variable stiffness (CCVS) is presented as a novel solution to improve the load carrying capacity of a fuselage panel with a cutout. The CCVS technique allows for the tow path...

Abstract: This paper explains the novel conformal antenna design that achieves better Bandwidth (0.53 GHz) and Gain (9 dB) with slim and flexible substrate suitable for aircraft fuselage mounting. The achiev...

Abstract: The application of wireless power transfer in the unmanned aerial vehicles (UAV) is becoming more and more extensive. In order to meet the requirements of miniaturization and lightweight, the fuselage of UAV often uses carbon fiber materials and the influence on the magnetic field distribution and energy transmission cannot be ignored. In this paper, the eddy current loss of the carbon fiber fuselage is simulated and analyzed, and the effect of the aluminum shielding method is studied. The study found that by optimizing the parameters such as the size, thickness and position of the shielded aluminum ring, the total system loss will be better improved, and the weight is light, which will not affect flight. Finally, a 500 W prototype is established to validate the method.

Abstract: This work demonstrates the calibration of an experimental air data probe on an atmospheric research aircraft by means of the Trailing Cone method. The probe under investigation is located on a nose boom in order to minimize the aerodynamic influence of the fuselage on the pressure measurement ahead of the aircraft. However, the data from this experiment proves that this configuration is still subject to significant pressure deviations from the undisturbed atmospheric values. This work demonstrates the determination of this error and presents an appropriate parameterization of the data which is prerequisite to provide accurately corrected pressure readings from this sensor. The experiment covers the determination of the proper configuration (length) for the Trailing Cone assembly, the validation of the method itself and the subsequent calibration of the air data sensor. Several improvements were applied to the Trailing Cone method in order to reduce the flight test effort as well as to significantly enhance the accuracy of the method itself. As a consequence a total of only three test flights was necessary to validate the method and to calibrate the air data sensor. The data analysis shows that the accuracy of the Trailing Cone reference measurement is very close to the pressure sensor calibration limit of 0.1hPa. The resulting accuracy of the corrected pressure measurement by the nose boom mounted pressure probe was demonstrated to be about 0.2 hPa, which represents the 3σ value.

Abstract: This research concerns the crashworthiness study and enhancement of commercial aircraft fuselage structures by incorporating crushable hybrid energy absorbers to work as vertical struts. To assess ...

Abstract: The Boeing 777 (sometimes referred to as Triple 7) is a large-capacity subsonic long-haul bomber aircraft built by the American company Boeing. This type of aircraft holds the current record of autonomy for commercial jets (17,450 km without food). Other special features of the aircraft include the perfect circular fuselage, a set of six wheels on each axle of the landing gear and the ability to be equipped with the high-performance General Electric GE90 engine. The 777 has been exclusively designed using CAD technology (with CATIA version 3), being the first airplane designed without building test structures before. Verification of joints and construction techniques has also been done digitally, with all the structures built up being included in the actual aircraft. The aircraft was designed to serve as an immediately superior Boeing 767 model and was built in airline consultancy (United Airlines, American Airlines, Delta Air Lines, ANA, British Airways, JAL, Qantas and Cathay Pacific) came from United Airlines in 1990 and the first flight took place on June 14, 1994, at the Boeing factory in Everett, near Seattle. It was the first ETOPS 180 bimonthly aircraft (it can fly up to 180 min from any airport able to take it). It is one of the best-selling (two-color) passenger airplanes in history, of which 988 were ordered, of which 635 were already delivered to the airlines. Its main competitors are Airbus A330 (for medium distance routes), Airbus A340 (for long-distance routes, with the claim that this model has the disadvantage of having four engines) and the future of the Airbus A350XWB-1000. Boeing plans to replace the model with the Yellowstone 3 code model in 2012-2015. The aircraft is equipped with modern technologies: Digital flight instruments offered by Honeywell LCD panels, fly-by-wire control, manual back-up systems, fully controllable avionics from software, use of composite materials on a larger surface (9% by mass), optical fiber as the primary transmission and control system for avionics, the largest and most powerful engine ever installed in a commercial aircraft (GE90-115B1) and the largest landing gear plus, the landing train allows the highest maximum weight on a wheel of all commercial jets - 23.73 t). The aircraft also uses classic technologies - such as the classic jump, unlike the Airbus models that have switched to joysticks. Similarly, the front section (section 41) is identical to that of the Boeing 767. For the comfort of pilots and crew members over long distances, there is a special resting space above the passenger cabin, complete with beds. In fact, the entire interior of the plane was new and then used in other models.

Abstract: The mean flowfield in the aft region of cargo aircraft configurations is analyzed using large-eddy simulations. A simplified surrogate fuselage is considered, consisting of a cylinder with axis par...

Abstract: This paper presents the results of research on the airflow around a multirotor aircraft. The research consisted of the analysis of the velocity field using particle image velocimetry. Based on the tests carried out in a wind tunnel, the distribution of the velocity and its components in the vertical plane passing through the propeller axis were determined for several values of the angle of attack of the tested object for two values of airflow velocity inside the tunnel, i.e., vwt = 0 m/s and vwt = 12.5 m/s. Determining the velocity value as a function of the coordinates of the adopted reference system allowed for defining the range of impact of the horizontal propellers and the fuselage of the research object itself. The tests allowed for quantitative and qualitative analyses of the airflow through the horizontal rotor. Particular attention was paid to the impact of the airflow and the angle of attack on the obtained velocity field distributions.

Abstract: In this work, a novel optimization framework, based on a Multi-Disciplinary Optimization (MDO) procedure, applied to the vibro-acoustic Finite Element Method (FEM) model of an aircraft fuselage mock-up, is proposed. The MDO procedure, based on an Efficient Global Optimization (EGO)-like approach, is implemented to characterize acoustic sources that replicate the sound pressure field generated by the engines on the fuselage. A realistic sound pressure field, evaluated by aeroacoustic simulations, was considered as the reference acoustic load, whereas two equivalent sound fields, displayed by two different arrays of microphones and generated by the same configuration of monopoles, were calculated by the proposed vibro-acoustic FEM-MDO procedure. The proposed FEM-MDO framework enables to set up ground experimental tests on aircraft components, useful to replicate their vibro-acoustic performances as if tested in flight. More in general, such a procedure can also be used as a reference tool to design simplified tests starting from more complex ones.

Abstract: A double-positions 4-PPPS parallel mechanism is used for the aircraft fuselage assembly process to improve the docking efficiency and reduce the labor intensity. However, the accuracy is hard to guarantee, for the mechanism is large and redundant and has manufacturing and assembly errors. To improve the accuracy of the 4-PPPS parallel aircraft fuselage docking system, firstly, an averaging iteration method is proposed to calibrate the datum points in the airplane coordinate which are the references of the entire docking system. And secondly, a kinematic calibration method based on the derivative of the spatial pose transformation is proposed to calibrate up to 42 kinematic parameters. By these two methods, the final maximum position error reduced from 2.2 mm to 0.035 mm and the maximum pointing error reduced from 0.08 degree to 0.018 degree. The accuracy measurement and docking experiment prove the efficiency of the proposed methods.

Abstract: Aircraft concepts, which utilize boundary layer ingestion as a means to increase airframe and propulsion system integrated performance, such as propulsive fuselage concepts, have been the subject of many studies in the recent past. High fidelity numerical and experimental methods have been employed to optimize fuselage and propulsor geometries and performance characteristics. However, some of the fundamental principles that relate the physical shape of a fuselage-propulsor to the potential benefit of boundary layer ingestion are still not fully understood. The presented methodology serves as a tool to investigate the effect of geometrical propulsor parameters and fuselage-propulsor fan pressure ratio on the performance of a propulsive fuselage aircraft concept. For this purpose, a method for the systematic design space exploration of a fuselage-propulsor configuration is presented and applied in a 2D axisymmetric CFD study.

Abstract: This paper develops a numerical method that is capable of analyzing the aerodynamic characteristic of the helicopter main rotor in consider influence of fuselage. The method is based on an unsteady nonlinear vortex-lattice method that can be used to simulate the interactions among the helicopter components efficiently. To clarify the effect of the main rotor-fuselage interaction, the aerodynamic characteristics of the main rotor in consider the influence of fuselage is determined along with those of the combined main rotor-fuselage system. The paper also shows the velocity field and free wake model in several flight regimes. The fuselage is modelled as a streamlined object, which is discretized into the system of quadrilateral vortex panels. The nopenetration boundary condition is satisfied on the fuselage surface, and no vorticity is shed from the fuselage. The results obtained in this paper are validated against experimental data and some from previous numerical methods.

Abstract: By applying finite element software ANSYS/LS-DYNA, finite element models of front bulkhead and main cabin are established, which aims to assess the dynamic response of fuselage structures impacted ...