Accurate navigation is required in many Unmanned Aerial Vehicle (UAV) applications. In recent years, GNSS Precise Point Positioning (PPP) has been recognised as an efficient approach for providing precise positioning services. In contrast to the widely used Real-Time Kinematic (RTK), PPP is independent of reference stations, which greatly broadens its scope of application. However, the accuracy and

A first attempt is made to use recently developed, non-conventional Artificial Neural Network (ANN) models with Multilayer Perceptron (MLP), Radial Basis Function (RBF) and Adaptive Neuro-Fuzzy Interference System (ANFIS) architectures to predict the fuel flow rate of a commercial aircraft using real data obtained from Flight Data Records (FDRs) of the cruise, climb and descent phases. The training

Accurate prediction of supersonic and hypersonic turbulent flows is essential to the design of high-speed aerospace vehicles. Such flows are mainly predicted using the Reynolds-Averaged Navier–Stokes (RANS) approach in general, and in particular turbulence models using the effective viscosity approximation. Several terms involving the turbulent kinetic energy (k) appear explicitly in the RANS equations

Stratospheric airships are promising aircraft, usually designed as a non-rigid airship. As an essential part of the non-rigid airship, the envelope plays a significant role in maintaining its shape and bearing the external force load. Generally, the envelope material of a flexible airship consists of plain-weave fabric, composed of warp and weft fibre yarn. At present, biaxial tensile experiments are

Recent research on Flight-deck Interval Management (FIM), a modern technology for increasing safety and improving airspace and runway utilisation through self-spacing, has led to the development of a new rule-based logic for FIM, namely Interval Management – Speed Planning (IM-SP). In an initial benchmark study, IM-SP showed good spacing performance with a significant reduction in speed commands, a

Microwaves are a form of electromagnetic radiation commonly used for telecommunications, navigation and food processing. More recently microwave technologies have found applications in fibre-reinforced polymer composites, which are increasingly used in aircraft structures. Microwave energy can be applied with low power (up to milliwatts) for non-destructive testing and high power (up to kilowatts)

Multi-dimensional aerodynamic database technology is widely used, but its model often has the curse of dimensionality. In order to solve this problem, we need projection to reduce the dimension. In addition, due to the lack of traditional method, we have improved the traditional flow field reconstruction method based on artificial neural networks, and we proposed an array neural network method. In

A trajectory optimisation procedure is addressed to generate a reference trajectory for Satellite Launch Vehicles (SLVs). Using a grid-based discrete scheme, a Modified Minimum Cost Network Flow (MCNF)-based algorithm over a large-scale network is proposed. By using the network grid around the Earth and the discrete dynamic equations of motion, the optimum trajectory from a launch point to the desired

This study investigates and proposes a fire detection and suppression system for a smart air cargo container. A series of smoke spread and fire evolution numerical models are executed to assess the performance of container-based fire detection in various fire scenarios. This is to identify the worst case and optimise the location and threshold setting of fire detection sensors, achieving the shortest

In conventional linear parameter-varying (LPV) modelling and gain scheduling control design for turbojet engines, the linearisation is performed at a set of equilibrium points, and the validity of such LPV models is ensured near the equilibria. However, the linear model can only provide an approximate description of the engine’s state when the system operates away from equilibrium. In this paper, it

To improve the endurance performance of long-endurance Unmanned Aerial Vehicles (UAVs), a smart morphing method to adjust the UAV and flight mode continuously during flight is proposed. Using this method as a starting point, a smart morphing long-endurance UAV design is conducted and the resulting improvement in the endurance performance studied. Firstly, the initial overall design of the smart morphing

In this article, we investigate the horizontal trajectory tracking problem for an underactuated stratospheric airship subject to nonvanishing external disturbances and model uncertainties. By transforming the tracking errors into new virtual error variables, we can specify the transient and steady-state tracking performance of the resulting nonlinear system quantitatively, which means that under the

Targeting higher efficiencies and lower fuel consumption of turbomachines, heat transfer and profile loss are research topics of particular interest. In contrast to that, the interaction of both was, so far, rarely investigated, but gains in importance in recent research activities. The profile loss of engine components can be characterised by the airfoil wakes at the blade rows utilising established

One of today’s most propitious immersive technologies is virtual reality (VR). This term is colloquially associated with headsets that transport users to a bespoke, built-for-purpose immersive 3D virtual environment. It has given rise to the field of immersive analytics—a new field of research that aims to use immersive technologies for enhancing and empowering data analytics. However, in developing

A range of quasi-steady and unsteady aerodynamic models are used to predict the aerodynamic forces experienced by a flapping wing and a detailed comparison amongst these predictions in provided. The complexity of the models ranges from the analytical potential flow model to the computational Unsteady Vortex Lattice Method (UVLM), which allows one to describe the motion of the wake and account for its

The aerodynamic performance of a deployable and low-cost unmanned aerial vehicle (UAV) is investigated and improved in present work. The parameters of configuration, such as airfoil and winglet, are determined via an optimising process based on a discrete adjoint method. The optimised target is locked on an increasing lift-to-drag ratio with a limited variation of pitching moments. The separation that

Dynamic soaring improves the endurance of Unmanned Aerial Vehicles (UAVs) by obtaining energy from the horizontal wind shear gradient. The use of dynamic soaring in small solar UAVs can mitigate the trade-off between energy capacity and battery weight to achieve continuous all-day flight. The goal of this study is to determine the optimal energy acquisition methods for small solar UAVs using dynamic

In this work, consideration is given to a novel concept for aerofoil lift enhancement and delaying flow separation. Here, lift enhancement is attained by preventing the growth of the boundary layer through the elimination of the zero-slip condition between the wing surface and the air stream. The concept would simulate all the effects of a moving wall, leading to the appearance of a slip velocity at

This paper presents the design, manufacturing and experimental assessment of a morphing element consisting of a composite corrugated panel that hosts a diffused actuation system based on Shape Memory Alloy (SMA) actuators. The characterisation of the SMA actuators is reported and the system performance is predicted through an analytical model and finite element analyses. Two versions of the actuated

Lack of flexibility limits the performance enhancement of man-made flapping wing Micro Air Vehicles (MAVs). Active chordwise deformation (bending) is introduced into the flapping wing model at low Reynolds number of Re = 200 in the present study. The lattice Boltzmann method with immersed boundary is adopted in the numerical simulation. The effects of the bending amplitude, bending frequency and phase

Aircraft sequencing and scheduling within terminal airspaces has become more complicated due to increased air traffic demand and airspace complexity. A stochastic mixed-integer linear programming model is proposed to handle aircraft sequencing and scheduling problems using the simulated annealing algorithm. The proposed model allows for proper aircraft sequencing considering wind direction uncertainties

Metal-composite airframes will suffer various defects during their lifetime. One category of defects is composite laminate delamination. This study evaluates the criticality of delaminations existing around adjacent fastener holes in the carbon-fibre-reinforced plastic spar web of the F/A-18 aircraft’s trailing-edge flap. The evaluation is based on experiments and analyses. First, an intensive experimental

Oil-jet lubrication and cooling of high-speed gears is frequently employed in aeronautical systems, such as novel high-bypass civil aero engines based on the geared turbofan technology. Using such oil-jet system, practitioners aim to achieve high cooling rates on the flanks of the highly thermally loaded gears with minimum oil usage. Thus, for an optimal design, detailed knowledge about the flow processes

Motivated by the idea of turbomachinery active subspace performance maps, this paper studies dimension reduction in turbomachinery 3D CFD simulations. First, we show that these subspaces exist across different blades—under the same parametrisation—largely independent of their Mach number or Reynolds number. This is demonstrated via a numerical study on three different blades. Then, in an attempt to

We present a hybrid, semi-analytical approach to perform an eigenvalue-based flutter analysis of an Unmanned Aerial Vehicle (UAV) wing. The wing has a modern design that integrates metal and composite structures. The stiffness and natural frequency of the wing are calculated using a Finite Element (FE) model. The modal parameters are extracted by applying a recursive technique to the Lanczos method

Uncertainty in the critical amplification factor ( $N_{cr}$ ) of the $e^N$ transition model is used to approximate the uncertainty in the surface and flow quality of natural laminar flow (NLF) aerofoils. The uncertainty in $N_{cr}$ is represented by a negative half-normal probability distribution that descends from the largest $N_{cr}$ achievable with an ideal surface and flow quality. The uncertainty

The coexistence of multiple stable states is indicative of self-organising processes occurring in the course of the combustor-inlet interactions in a ramjet engine and give rise to the appearance of various nonlinear phenomena. This paper provides a dynamic model that can describe the multiple stable states and the corresponding nonlinear effects to further investigate the dynamic interactions between

This work aims to describe a mathematical model and a numerical method to simulate a thin anisotropic membrane moving and deforming in 3D space under a dynamic load of an arbitrary time and space profile. The anisotropic continuum medium model described in the article can be used to model a membrane made of composite material using its effective elastic parameters. The model and the method allow the

This paper is one of a series addressing the need for simple, yet accurate, methods for the estimation of cruise fuel burn and other important aircraft performance parameters. Here, a previously published, constant Reynolds number model for turbofan-powered, civil transport aircraft is extended to include Reynolds number effects. Provided the variation of temperature with pressure is known, the method

The aeroelastic phenomenon of limit-cycle oscillations (LCOs) is analysed using a projection-based reduced-order model (PROM) and Navier–Stokes computational fluid dynamics (CFD) in the time domain. The proposed approach employs incompressible Navier–Stokes CFD to construct the full-order model flow field. A proper orthogonal decomposition (POD) of the snapshot matrix is conducted to extract the POD

Electric-powered disposable unmanned aerial vehicles (UAVs) have wide applications due to their advantages in terms of long time flight and load capacity. Thus, improving their endurance has become an important task to enhance the performance of these UAVs. To achieve this, we investigated a battery dumping strategy which splits the battery into several packs that are used and dumped in sequence to

One of the most critical aspects of a small satellite is the electrical power system (EPS) since the electrical power is necessary for the satellite to operate correctly during its predefined lifetime. The electrical power system consists mainly of solar cells, batteries, voltage converters and protection circuits. The electrical power system is responsible of providing stable power to the rest of

This paper describes the application of low-order models to the prediction of the steady performance of axial compressors at sub-idle conditions. An Euler body-force method employing sub-idle performance correlations is developed and presented alongside a mean-line approach employing the same set of correlations. The low-order tools are used to generate the characteristic lines of the compressor in

This article presents a development of a simple analytical aerodynamic model capable of describing the effect of leading-edge vortices (LEVs) on the lift of rotating samara wings. This analytical model is based on the adaptation of Polhamus’ method to develop a sectional two-dimensional lift function, which was implemented in a numerical blade element model (BEM) of a rotating samara blade. Furthermore

This paper deals with modelling the performance of an air transport network operated by existing subsonic and the prospective supersonic commercial aircraft. Analytical models of indicators of the infrastructural, technical/technological, operational, economic, environmental, and social performance of the network relevant for the main actors/stakeholders involved are developed. The models are applied

The early conceptual design (CD) phase of space access vehicles (SAVs) is the most abstract, innovative and technologically challenging phase of the entire aerospace design life cycle. Although the design decision-making during this phase influences around 80 percent of the overall life cycle cost, it is the most abstract and thus least understood phase of the entire design life cycle. The history

“Urban air vehicles” have been hailed as the next revolution in aviation. Prototypes of various sizes have been flown to demonstrate basic flight (hover and climb), but in most cases there is no demonstration of full flight capability, for example conversion from vertical to level flight (conversion corridor). There are proposals for vehicles in a wide range of scales: from drones specifically designed

This paper presents the development and implementation of a user-defined material (UMAT) model for NiTi Shape-Memory Alloy (SMA) wires for use in LS-DYNA commercial explicit finite-element analysis software. The UMAT focusses on the Shape-Memory Effect (SME), which could be used for actuation of aerostructural components. The actuation of a fundamental structure consisting of an SMA wire connected

This paper provides a solution to the active vibration control of a microsatellite with two solar panels. At first, the microsatellite is processed as a finite element model containing a rigid body and two flexible bodies, according to the principles of mechanics, and that the dynamic characteristics are solved by modal analysis. Secondly, the equation involving vibration control is established according

Considering the decision-making requirements of airport, airlines and passengers, a bilevel programming model which contains two parts was proposed in this paper. One part is to improve the utilization of gates of the airport (upper level), so the objective function of the upper level to the minimum overall variance of slack time between two consecutive air crafts at the same gate. The other part looks

The need for autonomous location estimation in the form of optical navigation is an essential requirement for forthcoming deep space missions. While crater-based navigation might work well with larger bodies littered with craters, small sub-kilometer bodies do not necessarily have them. We have developed a new pose estimation method for absolute navigation based on photometric local feature extraction

The oil and gas industry relies heavily on helicopters for transporting personnel and cargo to and from offshore installations and support vessels. A growing number of offshore helicopter operations are to moving helidecks, which include large vessels such as FPSOs, drill ships, and semi-submersibles, as well as smaller service vessels. Landing a helicopter on a moving helideck presents additional

The background and rationale for the research reported in this paper is detailed in the companion paper subtitled Part A: Modelling the on-deck helicopter Reserve of Stability (ROS). This paper (Part B) derives the fundamental principles underpinning the safe operational envelope and the definition of Motion Severity and Wind Severity Indices (MSI/WSI), and then presents the probabilistic modelling

Air-breathing propulsion has the potential to decrease the cost per kilogram for access-to-space, while increasing the flexibility of available low earth orbits. However, to meet the performance requirements, fuel-air mixing inside of scramjet engines and thermal management still need to be improved. An option to address these issues is to use intrinsically generated vortices from scramjet inlets to

In demand of simpler and alternative ground flutter test, a new technique that emulates flutter on the ground has recently emerged. In this paper, an improvement of the test technique is made and verified through the experimental work. The technique utilizes general ground vibration test (GVT) devices. The key idea is to emulate the distributed unsteady aerodynamic force by using a few concentrated

Distributed real-time avionics networks have been subjected to a great evolution in terms of functionality and complexity. A direct consequence of this evolution is a continual growth of data exchange. AFDX standardised as ARINC 664 is chosen as the backbone network for those distributed real-time avionics networks as it offers high throughput and does not require global clock synchronisation. For

The objective of this study is to identify, evaluate, and provide recommendations towards the realisation of near-term hypersonic flight hardware through the consideration of carrier vehicle constraints. The current rush of available funds for hypersonic research cannot cause a program to ignore growth potential for future missions. The prior NB-52 carrier vehicles, famous for the X-15 and X-43A missions

Numerical investigation of the effect of pylon geometry within a pylon-cavity aided Supersonic Combustion Ramjet (SCRAMJET) combustor on mixing enhancement, flame-holding capability, fuel jet penetration and total pressure loss are conducted in the current study. RANS equations for compressed real gas are solved by coupled, implicit, second-order upwind solver. A two-equation SST model is used for

Turbo-electric propulsive fuselage aircraft featuring Boundary-Layer Ingestion (BLI) are considered promising candidates to achieve the emissions reduction targets set for aviation. This paper presents an analytical method capable of estimating the BLI benefit at aircraft level, enabling a quick exploration of the propulsive fuselage design space. The design space exploration showed that the assumptions

Pilots are sometimes not provided with sufficient information to avoid go-arounds or other operational disruptions that result from low-level wind disturbances. We identified issues with existing windshear alerting systems and developed three types of airport low-level wind information systems to enhance pilot situational awareness of wind conditions by providing landing aircraft with quantitative

A novel second-order sliding-mode-based impact angle and autopilot lag guidance law for engaging manoeuvering targets with unknown acceleration is presented in this study. A backstepping technique is applied to the design of the sliding surface. The proposed guidance law is based on a new sliding surface. It exhibits the advantage of ensuring that the sliding surface and its derivative will converge

Rotor Track and Balance (RTB) is an important part of regular helicopter maintenance. The ability to perform this service assessment during normal operations, rather than with a series of explicit RTB flights, would greatly reduce the time the vehicle is non-operational and the maintenance costs associated with these flights and adjustments. This paper presents a novel methodology for identifying the

The gas temperature of the supersonic heat airflow simulated test system is mainly determined by the fuel and air flow rates which enter the system combustor. In order to realise a high-quality control of gas temperature, in addition to maintaining the optimum ratio of fuel and air flow rates, the dynamic characteristics of them in the combustion process are also required to be synchronised. Aiming

Because the wing-structure weight required to support the critical wing section bending moments is a function of wingspan, net weight, weight distribution, and lift distribution, there exists an optimum wingspan and wing-structure weight for any fixed net weight, weight distribution, and lift distribution, which minimises the induced drag in steady level flight. Analytic solutions for the optimum wingspan

Extensive research in recent years has focused on improving the current loss-of-control prevention systems and developing new strategies for safe path planning of the impaired aircraft. Success in developing such systems requires a comprehensive perception of the influence of damage on the aircraft’s dynamic behaviour and performance, and the effect of various failure degrees on the flight envelope

The development of oceanography and meteorology has greatly benefited from satellite-based data of Earth’s atmosphere and ocean. Traditional Earth observation missions have utilised Sun-synchronous orbits with repeat ground tracks due to their advantages in visible and infrared wavelengths. However, diversification of observation wavelengths and massive deployment of miniaturised satellites are both

This paper proposes a fault-tolerant control (FTC) method based on fast fault observer (FFO) to solve the problem of actuator gain loss fault and stuck fault for hypersonic vehicles. Firstly, an input-output feedback linearisation model is presented that considers parametric uncertainties, control input saturation, disturbances and actuator faults. Secondly, the above factors are defined as an integrated

Metop is the space segment of the EUMETSAT Polar System (EPS), which provides real-time data to several European meteorological services as well as to the National Oceanic and Atmospheric Administration (NOAA) and other international agencies. The third Metop satellite, Metop-C, was launched on 7 November 2018 and shall enter in operations in few months, once the on-going commissioning of the meteorological

This work presents a comparative study of design and development, in addition, of analyses of variable span morphing of the tapered wing (VSMTW) for the unmanned aerial vehicle (UAV). The proposed concept consists in the sliding of the inner section into the fixed part along the wing with varying the angle of the inner section inside the fixed part (parallel with the leading edge and the moving-wing

In this paper, a robust three-dimensional guidance law against manoeuvering targets is designed using the approach of discrete-time partial stabilisation. In the proposed method, the equations of the guidance problem are divided into two subsystems where the asymptotic stability is desired only for the first one. The control input of the second subsystem is designed such that the collision to be ensured