In this study, a design method is proposed and validated through experimental demonstration of a wing twist-morphing structure using a double-tube cylinder equipped with ribs at its closed section member. The details of the experiments are as follows: (i) specimens were made in accordance with the design method proposed, (ii) specimens were twisted and measured using a photogrammetric measurement system, and (iii) the twist angle of each rib was calculated by measuring the movement of each marker. The validity of the design method was evaluated by comparing the results between theoretical values and experimental values. Although the values obtained from the experiments are found to be lower than those obtained from theoretical calculations, especially at the wing-tip side, the trend is still in line with the theory. This indicates that the method derived is effective and applicable to designing wing twist-morphing structures.

Morphing wing technology is anticipated as a way to improve efficiency over a wider range of flight conditions, but it is difficult to realize morphing because there are two conflicting demands, i.e. stiffness for aerodynamic forces and flexibility for morphing. Super-anisotropy of the corrugated panel is a solution to satisfy those demands. This paper focuses on applying camber morphing to vertical plane. Firstly, optimal deformation of airfoil for morphing control surfaces is defined by conducting airfoil analysis. For realizing optimal deformation, deformation analysis of corrugated panels is conducted and evaluated by using high flexible 2-D beam equations.

More flexible and economical access to space is achievable using hypersonic air-breathing propulsion. One of the main challenges for hypersonic air-breathing propulsion is reaching high combustion efficiency within the short residence time of the flow in the engine. Lengthening the combustor is not a viable option due to its many drawbacks, and the use of hypermixers or strut injectors increases mixing efficiency at the cost of increasing losses and heat load. On the contrary, inlet-generated vortices are an intrinsic feature of many scramjet inlets, and can be used to enhance mixing, incurring minimal losses and heat load increase. A previous computational study used a canonical geometry consisting of a flat plate with a fin at different deflection angles to investigate the ability of inlet-generated vortices to enhance the mixing rate. Significant increases in mixing rate were obtained due to the vortex-fuel plume interaction. The flow conditions were equivalent to those found in a rectangular-to-elliptical shape transition scramjet inlet at a Mach 12, 50 kPa constant dynamic pressure trajectory. Despite the minimal heat load increase of this approach, characterization of the vortex-fuel plume interaction effect on the wall heat transfer is required. In this work, the previous study is extended, describing the effect of the vortex-fuel plume interaction on wall heat transfer. Heat flux in the vicinity of the porthole injector reaches 200% compared to the baseline case with no vortex interaction. Moreover, the injection bow shock affects the corner region, creating pockets of heat flux up to 75% larger than the unaffected region. Additionally, the evolution of the fuel plume downstream of the injector location is investigated, describing the relationship between local maxima and minima of heat flux, and the location of the fuel on the wall surface. This relationship can be exploited in experimental data acquisition to obtain the fuel location from heat flux data. The viability of this experimental approach is explored using computational data, confirming that through careful sensor placement, position measurements with an accuracy higher than ±5mm can be achieved.

In this paper, we propose a novel type of aerial manipulation. The system proposed utilizes an eye-in-hand type of parallel manipulator with a visual sensor system attached on the end-effector. The aerial parallel manipulator can maximize the advantages of the serial manipulator while minimizing the combined shortcomings. In order to enhance these advantages, we derive the loosely coupled end-effector dynamics and apply them in the host vehicle utilizing a simple control law. Furthermore, we propose a vision-enabled end-effector control architecture based on the inverse kinematics of the parallel robot. The system proposed is verified and validated by performing a flight test.

A noncontact method of measuring the strain on a wire-mesh surface using a digital image correlation technique was developed and its feasibility was investigated. In this method, the mesh feature is utilized; thus, target markers, painting, and strain gauges on the mesh surface are not required. The strain on the mesh surface is estimated based on changes in the spatial frequencies of the mesh grating (mesh regularity), and the digital image correlation technique is used to clar-ify the regularity of the mesh by calculating the distribution of the similarities. The spatial frequency of the mesh grating is evaluated using fast Fourier transform (FFT) analysis of the similarities.

In this study, Welch's method is employed to reduce the influence of noise caused by imperfect and finite data. Then, a quadratically interpolated FFT (QIFFT) method is used to find the spectral peak. The spatial frequency of the mesh grating in the digital image captured is affected by the mesh's angle of tilt and distance from the camera. Therefore, a method to correct the effects of the mesh's angle of tilt and distance of the mesh from the camera on the estimated spa-tial frequency was also developed based on the shape measurement results obtained using a stereoscopic vision system. Experiments were conducted to investigate the feasibility of these methods. The camera captured the images of the mesh. The spatial frequencies of the mesh grating were analyzed using FFT and corrected using digital image correla-tion with the shape measurement results obtained using the stereoscopic vision system. The results of the experiments were in good agreement with the test conditions we set, thus clearly indicating the efficiency of the method developed.

Modern airliners use the profiles calculated by the onboard flight management system (FMS) to execute safe and efficient descents. Since the wind often varies greatly between the cruising altitude and the end-of-descent altitude, the FMS uses both predicted and measured wind to determine the descent profile. Even so, the actual wind encountered along the descent changes the profile. When a constant descent speed is maintained at idling thrust, the aircraft deviates from its path and needs to either fly an additional steady level flight segment to the metering fix or deflect speed brakes to ensure the speed constraints at the metering fix are met. This research analyses the optimal top of descent in respect to such wind prediction error and fuel burn. Numerical simulations for the Boeing 767-300 are done and it is shown that an early descent of 0.5 nm would save, on average, 0.9 lb of fuel for an idling descent from 30,000 ft to 10,000 ft and at a constant speed of 280 kt, and decrease the number of cases where the necessary deceleration could not be achieved due to lack of enough lateral distance by 77%, thus improving safety and easing operations.

The use of adhesives for aircraft structural bonding and repairs is increasing due to the many benefits, including, reducing the overall weight of the aircraft and increasing the fatigue life of joints. However, many commercial adhesives used in the industry, such as Hysol® EA 934NA, typically require five to seven days to cure at room temperature, affecting aircraft down time. SATTO® is a product that is currently used as a filler for repairing aircraft cabin plastic, such as seats, trays, cabin paneling, etc., and cures within 30 minutes (SATTO® Filler). The chemical composition of SATTO® Filler was modified to improve its adhesive properties, while maintaining short curing times (SATTO® Adhesive). The use of this product in structural applications would be attractive as repairs could be conducted more rapidly, even at the gate, with minimum down time. This paper presents the results of a series of bolt pull-out tensile tests conducted with both SATTO® products as a potting adhesive for honeycomb inserts. The tests were conducted at various cure times in order to determine the cure time for optimum strength. The results were compared with the results of similar tests conducted with Hysol® EA 934NA at the recommended 5-7 days cure time. The results show that in this application the SATTO® products do not cure in 30 minutes and have a lower bonding strength than Hysol® EA 934NA. However, the tests do show that the SATTO® products are capable of carrying a moderate load at a cure time of about 2 hrs.

The purpose of the present study is to characterize the flow of CO₂-N₂-Ar plasma in a hollow electrode arc heater using optical diagnostics. Spectroscopic measurements are conducted in the region of the arc-heated part. The rotational and vibrational temperatures are determined from the measured spectra of CN Violet Δv=0 and C₂ Swan Δv=0 using a spectrum fitting technique. It is found that the rotational and vibrational temperatures are almost same, showing that the plasma in the arc heater is close to thermal equilibrium. The chemical composition of the plasma is calculated using the NASA-CEA program. The result shows that Ar, CO, and O are dominant species in the plasma investigated in this study. Although the mole fractions of CN and C₂ are extremely low, they are strong radiators in the CO₂-N₂-Ar plasma. The numerical spectrum in the wide wavelength range is calculated using the chemical composition deduced by the NASA-CEA program and compared with the measured one. The result shows that the numerical spectrum does not agree with the measured one due to contamination caused by carbon. Spectrum calculations are conducted parametrically by changing the chemical composition to investigate the influence of carbon contamination. The numerical spectrum becomes close to the measured one when the mole fractions of CN and C₂ decrease, showing that carbon contamination has a significant influence on the reaction processes of the plasma in the arc heater.

This paper investigates the relationship between natural frequencies and different braiding parameters: the braiding angles and the fiber volume fractions for three-dimensional, four-directional (3D4d) braided composites. A systematic experiment was set up and conducted, and a corresponding finite element model was built to analyze the experimental results. Since the rate of change among the first three orders of natural frequencies for changing braiding parameters are strongly monotonous, only the first order is analyzed. Based on experimental data, the relationship between the natural frequencies of the first order and the two types of braiding parameters are compared and discussed. The findings suggest that the natural frequency of this material and its 3D4d structure can be designable.

Morphing wings that transform their configuration seamlessly are expected to improve maneuverability and reduce noise and energy consumption of airplanes compared to conventional wings deformation including gaps and kinks. In addition, solid actuators such as electromagnetic motors and shape memory alloys (SMAs) reduce weight and maintenance cost compared to conventional hydraulic actuators. In this paper, a morphing flap model with a 500mm span × 642mm chord is developed, one-third of the trailing part of which deforms elastically. The actuator system is comprised of thin SMA wires and air blowers to improve the response of the SMA wires. Wind tunnel tests of the morphing flap model are carried out to check its controllability and examine its performance under aerodynamic loads.

When damage occurrs on a wing during flight, the stress at the damage site becomes large and the risk of catastrophic failure increases. In order to deal with this problem, Objective Stress Reduction (OSR) is considered by controlling the wing load distribution using an adaptive wing. The purpose of OSR is to reduce all or part of the stress acting on the wing. OSR also helps to adjust the extent of reduction depending on the condition in order to avoid increasing drag as much as possible. Static aeroelastic analysis is conducted for an adaptive wing model that has plain flaps at its leading- and trailing-edges using MSC/NASTRAN. From the results of a parametric study, it is revealed that the bending moment and drag are in a trade-off, and that OSR can adjust the extent of stress reduction depending on the various flight conditions by controlling the set of flap deflection angles.

As part of research into trajectory-based operations, we analyzed airspace and airport demand in the Fukuoka Flight Information Region for 2013 and 2030 to identify bottlenecks and understand future capacity requirements. Baseline traffic scenarios for selected days in 2013 were created from historical flight data. In this paper, we present a method to create forecast scenarios from baseline scenarios and a traffic growth forecast using a ‘copy-and-shift’ method that preserves characteristic flow peaks while increasing traffic. We also present a simple method for estimating the number of annual and hourly movements at airports from two ‘typical’ traffic scenario days and compared it with historical landing data to correct for traffic ‘missing’ from the baseline scenarios such as VFR traffic. We present the resulting 2030 forecasts of annual movements and typical runway demand for the eight busiest airports in Japan, and give comments regarding actual versus expected traffic and on the growth of the main Kanto region airports. A version of this paper presented at APISAT 2016 also contained an analysis of air traffic flows and international air route demand. This is omitted here due to page constraints, but the discussion on airport capacity from the previous paper has been expanded.

This research presents a new multi-objective path planning method for an unmanned aerial vehicle (UAV) using evolutionary computation. The proposed method searches for a desirable Pareto-optimal solution using an “aspiration point” and an “ideal point.” The aspiration point refers to the preference information for a decision maker (DM), and the ideal point represents a virtual solution that optimizes all objective functions simultaneously. All of the solutions generated in using evolutionary computation evolve toward the aspiration region, which is determined by the aspiration point. If a solution that is closer to the ideal point than the aspiration point is generated in the search process, the aspiration point is moved to the position of the solution point. This process is repeated until specific termination conditions are satisfied. Some results of the benchmark test problems show that the proposed method can efficiently generate the Pareto-optimal solution for the DM and a high probability compared to the existing method called the “weighted-sum method.” The usefulness of the proposed method is also shown by applying it to a multi-objective path planning problem that assumes an aerial photo-shoot mission using a UAV.

In the present study, the optical diagnostics of nonequilibrium argon plasma induced by a hypersonic shock wave are conducted based on a simple collisional-radiative (CR) model. Spectroscopic measurements show that line spectra of argon atoms are predominant and clearly seen in the near-infrared region. Line spectra of argon atoms and ion are observed in the visible region. However, the influence of contaminated gases is significant. The electron excitation population is deduced by applying the Boltzmann plot method to the measured line spectra of argon atom. The result shows that the electron excitation population is much different from the Boltzmann distribution, indicating that the argon plasma is in a thermal nonequilibrium state. Finally, the spatial distribution of the electron temperature is obtained by applying the CR model to the measured spectra and compared with that of the calculated one. It is found that the electron temperature obtained using the CR model qualitatively agrees well with the calculated one. The present result has indicated the possibility of using the simple CR model for determining the electron temperature of nonequilibrium argon plasma induced by a hypersonic shock wave.

A novel rotational internal combustion engine is invented and investigated as an auxiliary power unit (APU) of aircraft and range extension power unit for electric automobiles. For the intended applications, IC engines are required to have vibration-free characteristics. There are no reciprocating components in the present engine, resulting in vibration-free operation. This engine mainly consists of a rotor casing, a rotor and a crankshaft. The rotor is shaped in a single-lobe peritrochoid (S.L.P.) curve. The rotor is turned using a crankshaft eccentricity e and self-rotation in the counter-direction is achieved using phasing gears. The rotor casing shape has two cavities that define the envelope curve of the rotating single-lobe peritrochoid rotor. The space between the rotor and casing is where the processes for the working gas are performed: intake, compression, ignition, expansion and exhaust. The intake of premixed air/fuel gas and exhaust of burnt gas are controlled by rotary valves installed on the combustion recesses of the rotor-casing. The combustion recesses are equipped with spark-electrodes for ignition. One of the advantages of this engine compared to Wankel rotary engines and a previous engine invented by authors is easy and reliable sealing of the working gas. In this engine configuration, a sealing component is only installed on the waist section of the rotor-casing, instead of complex sealing system used for the rotor in the case of Wankel engines, resulting in higher efficiency by reducing the leakage of working gas.

In this paper, first the configuration and geometries of this engine are described. Next a prototype engine is introduced and the cyclic behavior of the working process of the engine is explained. The performance of the prototype engine driven by an electric motor is also shown.