Aeronautics and aerospace Research Papers (original) (raw)

The paper is about preliminary sizing and analysis of a trainer aircraft wing. The main objective is to fix an appropriate
structure within the given envelope and to estimate the Gross take-off weight, wing loading, Stress distribution, low
frequency vibrational modes, take-off distance and stall velocity. Sizing is done by using classical engineering theories and
FEA packages. Skin and web are considered as shell elements. Flange, spar and stringer are considered as beam elements.
From the analysis structure has been optimally designed which satisfies the strength and stability criteria. The detailed
design of trainer aircraft wing structure is modelled using CATIA V5 R20. Then stress analysis of the wing structure is
carried out by using the finite element approach with the help of MSC NASTRAN/PATRAN to find out the safety factor of
the structure.

Novel techniques for laser beam atmospheric extinction measurements, suitable for manned and unmanned
aerospace vehicle applications, are presented in this paper. Extinction measurements are essential to support the
engineering development and the operational employment of a variety of aerospace electro-optical sensor systems,
allowing calculation of the range performance attainable with such systems in current and likely future applications.
Such applications include ranging, weaponry, Earth remote sensing and possible planetary exploration missions
performed by satellites and unmanned flight vehicles. Unlike traditional LIDAR methods, the proposed techniques
are based on measurements of the laser energy (intensity and spatial distribution) incident on target surfaces of
known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for
radiance. Various laser sources can be employed with wavelengths from the visible to the far infrared portions of
the spectrum, allowing for data correlation and extended sensitivity. Errors affecting measurements performed
using the proposed methods are discussed in the paper and algorithms are proposed that allow a direct determination
of the atmospheric transmittance and spatial characteristics of the laser spot. These algorithms take into account a
variety of linear and non-linear propagation effects. Finally, results are presented relative to some experimental
activities performed to validate the proposed techniques. Particularly, data are presented relative to both ground and
flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm.
This includes ground tests performed with 10 Hz and 20 KHz PRF NIR laser systems in a large variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft.

- by Roberto Sabatini
- •
- Aerospace Engineering, Laser, Atmospheric Aerosols, Aerospace

A methodology for including maximum flutter
speed requirement in the preliminary structural
wing design is developed. The problem of
minimizing structural weight while satisfying
static strength, dynamic characteristic and
aeroelastic behavioural constraints is stated in
a non-linear mathematical form , with beam
width and thickness taken as design variables ,
and solved using gradient-based optimisation
technique. Dynamic characteristics of the
structure are calculated using finite element
model. Laplace form of the unsteady
aerodynamics forces are obtained from Fourier
transform of unit pulse aerodynamics response.
The frequency-domain p-k method is applied for
the calculation of aeroelastic stability
boundaries. Based upon constraint values and
the required gradients, a first order Taylor
series approximation is used to develop an
approximation linear programming for weight
minimization. A modified feasible direction
method is, then, applied iteratively to solve the
optimisation problem. Validation of the method
are carried out in the design of cantilever
straight wing structure with 6% hyperbolic
airfoil. It will be shown that the optimised wing
design can significantly differ from those
obtained without optimisation process.

- by Harijono Djojodihardjo
- •
- Aerodynamics, Aeronautics, Aeronautics and aerospace

Distributed Satellite Systems (DSS) provide a promising solution in increasing the sustainability of both the space and terrestrial environment through responsive Earth Observation (EO) and Space Domain Awareness (SDA) operations. To exploit the advantages of DSS mission architectures, a technical evolution is required from the deliberative methodologies of traditional ground station operations to approaches that are more suited to autonomous, reactive space mission architectures. At its core, this transition is directly reflected in the design, and development of new, more autonomous Mission Planning Systems that adopt the Adaptive Multi-Agent System (AMAS) framework. With a view towards trusted autonomy, this paper explores the required evolution towards a more supervisory role of future ground station operations. In doing so, this paper provides an initial analysis of a conceptual goal-based distributed space-based SDA application within the Observe Orient Decide and Act (OODA) decision loop framework.

- by Roberto Sabatini
- •
- Aerospace Engineering, Human Computer Interaction, Space Sciences, Ergonomics
- by Salman Salahuddin
- •
- Aerospace Engineering, Military History, Military and Politics, Aeronautics

The current project is a study of the 1-D linear advection equation that characterize the waves and represent the transport of substance by bulk motion.The system corresponds to an hyperbolic partial differential equation and takes a big interest when it comes to the study of the normal shock wave. To solve this equation, numerical methods are used and different schemes are introduced to better control the solution through stability, accuracy and consistency. In what follows, a numerical study and investigation of the 1-D Linear Advection Equation.

This summer training, carried out at Hindustan Aeronautics Limited (HAL),
Bangalore; included familiarizing with the various processes involved in the company from
the point of receiving of customer orders, the production processes involved; till the final
dispatch of the end product to the customers. HAL have various divisions therefore my
training is completed at the Aircraft division. In Aircraft division during the training we learn
whole procedure of aircraft manufacturing and also learn how can the biggest industry is
work as unit with systematic way. I am very happy to know that how do the done things in
practically way .We are understand that various type of work and procedure how to done .
It is very useful for us that different type of aircrafts and fighter jets how to complete
at workshop place. The main thing is that we see the live industrial experience in first time in
life and we meet the senior engineers and employs to get some knowledge about the field.
We see different type machining process those are specially use only in aircraft industries.

- by Aasan Aasan
- •
- Aerospace Engineering, Design, Manufacturing, Aeronautical Engineering
- by Emmanuel Dorméus
- •
- Aerospace Engineering, Aerospace, Aeronautics and aerospace

The demand for improved safety, integrity and efficiency due to the rapid growth of aviation sector and the growing concern for environmental sustainability issues poses significant challenges on the development of future Communication, Navigation and Surveillance/Air Traffic Management (CNS/ATM) and Avionics (CNS+A) systems. High-integrity, high-reliability and all-weather services are required in the context of four dimensional Trajectory Based Operations / Intent Based Operations (TBO/IBO). The Next Generation Flight Management Systems (NG-FMS) and the Next Generation Air Traffic Management (NG-ATM) systems are developed allowing automated negotiation and validation of the aircraft intents provided by the NG-FMS. After describing the key system architectures, the mathematical models for trajectory generation and CNS performance criteria evaluation are presented. In this paper, the method for evaluating navigation performance is presented, including a detailed Monte Carlo simulation case study. The proposed approach will form a basis for evaluating communication and surveillance performances as well in future research. The Monte Carlo simulation results demonstrate the capability of the proposed CNS+A system architectures to comply with the required navigation performance criteria in the generation of optimized aircraft trajectory profiles.

- by Roberto Sabatini
- •
- Aerospace Engineering, Aeronautical Engineering, Electronics, Aviation

This paper presents the concept of Cognitive Human-Machine Interfaces and Interactions (CHMI2) for Unmanned Aircraft Systems (UAS) Ground Control Stations (GCS). CHMI2 is a new approach to aviation human factors engineering that introduces adaptive functionalities in the design of operators' command, control and display functions. A CHMI 2 system assesses human cognitive states based on measurement of key psycho-physiological observables. The cognitive states are used to predict and enhance operator performance in the accomplishment of aviation tasks, with the objective of improving the efficiency and effectiveness of the overall human-machine teaming. The CHMI 2 system in this paper employs a four-layer architecture comprising sensing, extraction, classification and adaptation functionalities. An overview of each layer is provided along with the layer's metrics, algorithms and functions. Two relevant case studies are presented to illustrate the interactions between the different layers, and the conceptual design of the associated display formats is described. The results indicate that specific eye tracking variables provide discrimination between different modes of control. Furthermore, results indicate that higher levels of automation are preferred in Separation Assurance and Collision Avoidance (SA&CA) scenarios involving low-detectability obstacles. It is anticipated that the use of CHMI 2 systems in UAS SA&CA applications will reduce reaction time and enhance operational effectiveness in responding to collision avoidance/loss of separation events, as well as improving the overall safety of operations.

- by Roberto Sabatini and +1
- •
- Aerospace Engineering, Cognitive Psychology, Cognitive Science, Human Computer Interaction

Abstrak Masalah kepadatan penduduk sangat berdampak bagi perkembangan teknologi, selain itu kepadatan dan kemacetan lalu lintas juga sering dihubungkan dengan bertambahnya jumlah penduduk, dan meningkatnya penggunaan kendaraan pribadi. Pada kasus yang sangat krusial ini dengan pola kehidupan masyarakat dengan adanya inovasi teknologi baru yaitu Flying Car diharapkan dapat mengatasi permasalahan ini. Perancangan Konseptual Flying Car dengan kapasitas 3 penumpang dan 1 pilot dilakukan dengan menggabungkan prinsip kendaraan darat dan prinsip pesawat terbang dengan melakukan perhitungan estimasi berat, performance, dan geometri sizing menggunakan metode Roskam dan Raymer yang mengacu pada Regulasi Far 23 (Light Aircraft Four Seater, Normal Category) sehingga didapat nilai takeoff weight 2340lb, empty weight 1178 lb, Payload 1161 lb, baggage dengan geometri fuselage length 16,97ft, width 7.05ft, and height 7.76ft, serta wing area 167ft^2, wing span 32.8ft, dan telescopic wing and tail mechanism yang ditenagai oleh dual ducted fans engine sehingga mampu menghasilkan power sebesar 300hp, dengan kecepatan maximum 202.6knot, kecepatan jelajah 184knot, sehingga hanya memerlukan jarak takeoff 1309ft, dan jarak landing 1284ft kemudian direpresentasikan dalam bentuk geometri pada Software Catia dengan hasil akhir yang mampu mengungguli Design Requirement and Objective termasuk dari segi berat dan performance nya sehingga dapat disimpulkan bahwa Analysis Conseptual Design Flying Car berhasil dilakukan dan disarankan untuk dilakukan perhitungan selanjutnya pada bagian Aerodinamic, Stability and Control Dynamic, Performance Analysis, Preliminary Design dan Detail Design menggunakan metode Torrenbeek, Raymer dan lainnya. Teknologi transportasi adalah teknologi yang mampu mendukung pemindahan manusia atau barang dari satu tempat ke tempat lainnya dengan menggunakan sebuah kendaraan yang digerakkan oleh manusia atau mesin. Transportasi digunakan untuk memudahkan manusia dalam melakukan aktivitas sehari-hari. Istilah "teknologi" berasal dari "techne " atau cara dan "logos" atau pengetahuan. Jadi secara harfiah teknologi dapat diartikan pengetahuan tentang cara. Perkembangan teknologi yang semakin canggih, membuat beberapa bidang menjadi berkembang pesat, salah satunya dibidang transportasi udara Teknologi yang semakin maju serta murah dan mudah untuk memperoleh sebuah kendaraan membuat orang-orang lebih tertarik menggunakan kendaraan pribadi. Tidak bisa dipungkiri, faktor waktu, kenyamanan, kemudahan mengakses lokasi, serta keamanan yang menjadikan orang-orang beralih menggunakan kendaraan pribadi. Dampaknya, kian hari kendaraan-kendaraan pribadi, baik kendaraan roda dua maupun roda empat semakin menumpuk di ruas-ruas jalan, sehingga menimbulkan kemacetan dimana-mana, kemacetan tersebut juga terjadi di berbagai wilayah Kota Bandung seperti terlihat pada gambar berikut :

The heat barrier, resulting from shock waves, is the main problem to overcome in hypersonic flight. Shock waves start from the intersection of Mach waves, but it is shown that a suitable electromagnetic force field can modify the pattern. Computational and experimental studies involving magnetohydrodynamics are presented, allowing for shock wave cancellation and active aerodynamic control of an ionized flow through Lorentz force action. Further solutions are also considered for advanced aerospace applications of MHD converters using magnetized non-equilibrium plasmas. Nomenclature J = current density B = magnetic field F = Lorentz force V = flow velocity V s = surface wave speed ρ = fluid density L = interaction length η = interaction parameter a = speed of sound M = Mach number E = electric field σ = electrical conductivity R m = magnetic Reynolds number P = fluid pressure P m = magnetic pressure µ 0 = vacuum permeability T g = gas temperature T e = electron temperature

- by Fabrice DAVID and +2
- •
- Aeronautics and aerospace

Today, in 2021, a new generation of artists, activists, students, teachers, scientists, engineers, global humanity are engaging & evolving the internet. All part of the first GLOBAL polity, consciousness which emerged in 2020. Post-biosphere Collapse, Post-Anthropocene, Mid-Economic and Social Collapse. Most of the internet content from the last three decades is no longer extent, including my (Spaceplane, Aerospace, and Other) work. Viz. most webpages, all of Yahoo Groups, Google Groups, Google+, and Notes and everything which has been disappeared from Facebook. So today, with the help of the Wayback Machine, I downloaded and made a quick PDF of one of my X49 Stratoliner Spaceplane designs from two decades ago, which were once publicly available online. Hopefully, our rapidly-evolving (AI-assisted) humanity will make all of our internet history, and science, available and transparent in the coming years. And a thousand- and million-fold greater Global Humanity and Consciousness soon empower us. All Our Sacred Relations, our Health and Sanity, Returning ...

The HyShot 2 flight in 2002 pioneered a low cost method of hypersonic testing using sounding rockets. In a further development of this technology, Flight 7 of the HIFiRE Program will deploy a free-flying scramjet powered payload that is planned to enter the atmosphere at a high flight path angle at approximately Mach 8. The HIFiRE 7 payload consists of two back-to-back three-dimensional scramjet engines set within a trailing flare for aerodynamic stability. The scientific goals of the flight are to perform a direct measurement of the thrust generated by the scramjet flowpaths, and to compare the measured thrust with estimates based on ground testing. This paper describes the motivation, launch procedure, flowpath development and ground testing for the flight which is scheduled for March 2011.

- by Milinda Suraweera
- •
- Aerospace Engineering, Space Sciences, Aeronautical Engineering, Aerodynamics

This document details the procedure of calculation of orbital perturbation due to gravitational harmonics by simulation of various orbits at different altitudes and inclinations to the earth's equatorial plane. The orbits were first simulated and data of position and velocity was collected. The data was then analysed by another program to calculate the perturbations. Runge – Kutta fourth order method was used to simulate the orbits. The orbits were assumed to start from the perigee position which lied on the longitudinal plane containing the point of vernal equinox. The perturbations obtained were analysed w.r.t inclination of orbits and eccentricity of the orbits. The order of magnitude of the perturbations obtained were analysed w.r.t altitude. The earth was assumed to be symmetrical in all other terms.

The research presented in this paper focuses on the conceptual design of an innovative Air Traffic Management (ATM) system featuring automated 4-Dimensional Trajectory (4DT) Planning, Negotiation and Validation (4-PNV) functionalities to enable Intent Based Operations (IBO). In order to meet the demanding requirements set by national and
international organisations for the efficiency and environmental sustainability of air transport operations, a multi-objective 4DT optimization algorithm is introduced that represents the core element of the 4DT planning functionality. The 4-PNV system interacts with airborne avionics also developed for 4DT-IBO such as the Next Generation Flight Management System (NG-FMS) on-board manned aircraft and Next Generation Mission Management System (NG-MMS) for Remotely Piloted Aircraft Systems (RPAS). In this article we focus on the 4-PNV algorithms, and specifically on the multi-objective 4DT optimization algorithm for strategic and tactical online operations. Simulation case studies are carried out to test the key system performance metrics such as 4DT computational time in online tactical Terminal Manoeuvring Area (TMA) operations.

The optimum thrust of rocket engine is being delivered when the nozzle exit and ambient pressures are balanced. This poses a challenge with the operation of rocket engines when ascending altitudes since the ambient pressure decreases with the changing altitudes. There have been solutions designed to counter the effect of this variation in pressure with special rocket nozzles such as Aerospike nozzles, Deflection nozzles, extended nozzles, etc. However, these special nozzles add up to weight, mechanisms, rocket system engine staging and cost of production. This paper therefore looks at the rocket model that will enable thrust optimization along altitudes by determining (upstream) chamber pressure values with regards to the ambient pressure.

- by Sesugh Nongo
- •
- Space Sciences, Aeronautics and aerospace
- by la bv
- •
- Aeronautics and aerospace, Aeronautical

In recent years Air Traffic Flow Management (ATFM) has become pertinent even in regions without sustained overload conditions caused by dense traffic operations. Increasing traffic volumes in the face of constrained resources has created peak congestion at specific locations and times in many areas of the world. Increased environmental awareness and economic drivers have combined to create a resurgent interest in ATFM as evidenced by a spate of recent ATFM conferences and workshops mediated by official bodies such as ICAO, IATA, CANSO the FAA and Eurocontrol. Significant ATFM acquisitions in the last 5 years include South Africa, Australia and India. Singapore, Thailand and Korea are all expected to procure ATFM systems within a year while China is expected to develop a bespoke system. Asia-Pacific nations are particularly pro-active given the traffic growth projections for the region (by 2050 half of all air traffic will be to, from or within the Asia-Pacific region). National authorities now have access to recently published international standards to guide the development of national and regional operational concepts for ATFM, geared to Communications, Navigation, Surveillance/Air Traffic Management and Avionics (CNS+A) evolutions. This paper critically reviews the field to determine which ATFM research and development efforts hold the best promise for practical technological implementations, offering clear benefits both in terms of enhanced safety and efficiency in times of growing air traffic. An evolutionary approach is adopted starting from an ontology of current ATFM techniques and proceeding to identify the technological and regulatory evolutions required in the future CNS+A context, as the aviation industry moves forward with a clearer understanding of emerging operational needs, the geo-political realities of regional collaboration and the impending needs of global harmonization.

- by Trevor Kistan and +3
- •
- Aerospace Engineering, Decision Making, Operations Management, Operations Research

For over a decade, the international aviation community has been considering the concept of Single-Pilot Operations (SPO) as a viable solution to the rising costs associated with commercial air transport. Recent advances in Communications, Navigation, Surveillance/Air Traffic Management and Avionics (CNS+A) technologies have allowed higher levels of automation, creating an opportunity for commercial airliners to transit to SPO. By leveraging CNS+A developments, the elevated workload of a single pilot can be mitigated through air-ground collaborative decision making in a number of ways: by expanding the role of ground operators; enhanced support in the strategic (flight planning), tactical (rerouting) and emergency (e.g., during pilot incapacitation) flight phases; as well as higher levels of decision support for the execution of complex tasks including separation assurance, collision avoidance, systems monitoring and landing. In the event of pilot incapacitation, on-board and ground CNS+A systems allow the aircraft to be operated as a Remotely Piloted Aircraft System (RPAS). Psychophysiological sensing and adaptive interfaces are introduced to enable the detection of pilot incapacitation while facilitating operations at higher levels of automation. The concept of a Virtual Pilot Assistant (VPA) system is presented as a possible technology solution introducing higher levels of autonomy and adaptive Human-Machine Interface and Interaction (HMI2) features. While technically possible, the transition to SPO requires an evolution of the current operational and pilot regulatory framework.

- by Roberto Sabatini and +1
- •
- Aerospace Engineering, Aeronautical Engineering, Airworthiness and Aircraft Accident Investigation, Autonomous Robotics

Modern Unmanned Aircraft Systems (UAS) employ a variety of sensors and multi-sensor data fusion techniques to provide advanced operational capabilities and trusted autonomy (i.e., required levels of safety, integrity, security and interoperability), when sharing the airspace with other manned and unmanned platforms. Low-cost and high-performance Navigation and Guidance Systems (NGS) for UAS have been developed at RMIT University by employing a combination of compact and lightweight sensors to satisfy the Required Navigation Performance (RNP) in all flight phases. Additionally, recent research at RMIT has focused on the development of a unified approach to separation assurance and collision avoidance suitable for UAS cooperative/non-cooperative sensor architectures and allowing for an extended range of operations both in mission-essential and safety-critical tasks. The Sense-and-Avoid Unified Method (SUM) developed at RMIT provides an innovative analytical framework to combine real-time measurements (and associated uncertainties) of navigation states, platform dynamics and tracking observables to produce high-fidelity dynamic geo-fences suitable for integration in future avionics, Air Traffic Management (ATM) and defense decision support tools.

A unified approach to cooperative and non-cooperative Sense-and-Avoid (SAA) is presented that addresses the technical and regulatory challenges of Unmanned Aircraft Systems (UAS) integration into non-segregated airspace. In this paper, state-of-the-art sensor/system technologies for cooperative and non-cooperative SAA are reviewed and a reference system architecture is presented. Automated selection of sensors/systems including passive and active Forward Looking Sensors (FLS), Traffic Collision Avoidance System (TCAS) and Automatic Dependent Surveillance – Broadcast (ADS-B) system is performed based on Boolean Decision Logics (BDL) to support trusted autonomous operations during all flight phases. The BDL adoption allows for a dynamic reconfiguration of the SAA architecture, based on the current error estimates of navigation and tracking sensors/systems. The significance of this approach is discussed in the Communication, Navigation and Surveillance/Air Traffic Management and Avionics (CNS+A) context, with a focus on avionics and ATM certification requirements. Additionally, the mathematical models employed in the SAA Unified Method (SUM) to compute the overall uncertainty volume in the airspace surrounding an intruder/obstacle are described. In the presented methodology, navigation and tracking errors affecting the host UAS platform and intruder sensor measurements are translated to unified range and bearing uncertainty descriptors. Simulation case studies are presented to evaluate the performance of the unified approach on a representative UAS host platform and a number of intruder platforms. The results confirm the validity of the proposed unified methodology providing a pathway for certification of SAA systems that typically employ a suite of non-cooperative sensors and/or cooperative systems.

- by Roberto Sabatini and +2
- •
- Robotics, Aerospace Engineering, Robotics (Computer Science), Sensors and Sensing

Modern Remotely Piloted Aircraft Systems (RPAS) employ a variety of sensors and multi-sensor data fusion techniques to provide advanced functionalities and trusted autonomy in a wide range of mission-essential and safety-critical tasks. In particular, Navigation and Guidance Systems (NGS) for small RPAS require a typical combination of lightweight, compact and inexpensive sensors to satisfy the Required Navigation Performance (RNP) in all flight phases. In this paper, the synergies attainable by the combination of Global Navigation Satellite System (GNSS), Micro-Electromechanical System based Inertial Measurement Unit (MEMS-IMU) and Vision-Based Navigation (VBN) sensors are explored. In case of VBN, an appearance-based navigation technique is adopted and feature extraction/optical flow methods are employed to estimate the navigation parameters during precision approach and landing phases. A key novelty of the proposed approach is the employment of Aircraft Dynamics Models (ADM) augmentation to compensate for the shortcomings of VBN and MEMS-IMU sensors in high-dynamics attitude determination tasks. To obtain the best estimates of Position, Velocity and Attitude (PVA), different sensor combinations are analysed and dynamic Boolean Decision Logics (BDL) are implemented for data selection before the centralised data fusion is accomplished. Various alternatives for data fusion are investigated including a traditional Extended Kalman Filter (EKF) and a more advanced Unscented Kalman Filter (UKF). A novel hybrid controller employing fuzzy logic and Proportional-Integral-Derivative (PID) techniques is implemented to provide effective stabilization and control of pitch and roll angles. After introducing the key mathematical models describing the three NGS architectures: EKF based VBN-IMU-GNSS (VIG) and VBN-IMU-GNSS-ADM (VIGA) and UKF based Enhanced VIGA (EVIGA), the system performances are compared in a small RPAS integration scheme (i.e., AEROSONDE RPAS platform) exploring a representative cross-section of the aircraft operational flight envelope. A dedicated ADM processor (i.e., a local pre-filter) is adopted in the EVIGA architecture to account for the RPAS maneuvering envelope in different flight phases (assisted by a maneuver identification algorithm), in order to extend the ADM validity time across all segments of the RPAS trajectory. Simulation results show that the VIG, VIGA and EVIGA systems are compliant with ICAO requirements for precision approach down to CAT-II. In all other flight phases, the VIGA system shows improvement in PVA data output with respect to the VIG system. The EVIGA system shows the best performance in terms of attitude data accuracy and a significant extension of the ADM validity time is achieved in this configuration.

- by Roberto Sabatini and +1
- •
- Aerospace Engineering, Computer Vision, Vision Science, Robot Vision

This paper presents the conceptual design of a Virtual Pilot Assistant (VPA) for single-pilot operations of commercial transport aircraft. In particular, a thorough requirement analysis was performed by taking into account existing literature on single pilot operations from general aviation and military standards. The analysis also considers relevant human factors engineering and system design aspects of conventional two-pilot aircraft and Remotely-Piloted Aircraft Systems (RPAS). The VPA performs a real-time assessment of the single-pilot's cognitive states and provides useful and timely alerts based on predictions on the performance levels of the pilot. In case of pilot incapacitation, the VPA enables the single-pilot aircraft to be operated as an RPAS, allowing ground operators to take over as necessary and make an emergency landing at a safe and suitable location.

- by Subramanian Ramasamy
- •
- Aerospace Engineering, Aeronautical Engineering, Electronics, Aviation

Recently two different L-band digital aeronautical communication systems (LDACS), L-DACS1 and L-DACS2 have been proposed as two Future Communication Infrastructure (FCI) candidates for Air-to-Ground (AG) communication systems, with L-DACS1 selected as the best candidate. In this paper we describe a filter bank multicarrier (FBMC) based communication system, and show its advantages over the LDACS systems. We provide simulation results for all three communication systems to fairly compare their power spectral density (PSD), peak-to-average power ratio (PAPR), and BER performance. We show that in a measurement-based AG communication channel model, FBMC has better performance (and spectral containment) than the L-DACS schemes, and this is particularly true in the presence of actual interfering signals from distance measuring equipment (DME). Simulation results show that FBMC can substantially reduce the out-of-band (OOB) power, and can suppress DME interference by at least 19.5 dB, due to its well-localized subcarrier prototype filters. FBMC can also increase throughput and spectral efficiency by reducing the number of guard-band subcarriers and removal of the cyclic prefix, postfix and windowing techniques used in L-DACS1. These results show that an FBMC based communication system can be an appealing candidate for future AG communication systems.

This paper explores the synergies between a novel Global Navigation Satellite System (GNSS) Avionics-Based Integrity Augmentation (ABIA) system and current Space and Ground Based Augmentation Systems (SBAS and GBAS). The ABIA Integrity Flag Generator (IFG) is designed to provide caution and warning integrity flags (in accordance with the specified time-to-caution and time-to-warning requirements) in all relevant flight phases. The ABIA IFG performances are assessed and compared with the SBAS and GBAS integrity flag generation capability. Simulation case studies are presented using the TORNADO-IDS platform and they provide insights on possible mutual benefits attainable by integrating ABIA with SBAS and GBAS systems. The results show that the proposed integrated scheme is capable of performing high-integrity tasks when GNSS is used as the primary source of navigation data. Furthermore, it is evident that there is a clear synergy of ABIA with SBAS and GBAS in providing suitable (predictive and reactive) integrity flags in all flight phases. The integration is thus a clear opportunity for future research towards the development of a Space-Ground-Avionics Augmentation Network (SGAAN) for a number of safety-critical aviation applications.

ARTICLE INFO ABSTRACT Swept wings are widely used in commercial Aircraft's to cruise at transonic speeds with drag comparatively less than straight wings at transonic speed conditions. On the other hand trainer aircrafts both for commercial and defence trainings are preferred with swept wings to attain higher critical Mach speeds which is very less in straight wing trainer Aircraft's. Swept wings are preferred for its high lift to drag ratio low speed takeoff conditions and for near sonic flight operating conditions. Much research work on swept wings were done in past and many more are being carried out by different research centres around the globe and aircraft manufacturer's, but still the performance and aerodynamics of swept wings at transonic speeds and under different Turbulence levels and conditions is a grey area which needs to be addressed. In this paper two different configuration of swept wing (30 0 and 40 0 sweep) is analyzed and presented for two different Transonic speeds of 0.7 Mach and 0.9 Mach. The 3D wing model analyzed and presented in this paper is of NACA2412 profile. The lift and drag coefficient of this 3d wing at 0 0 AOA and at 4 0 AOA is tabulated in this paper for two of sweep angles 30 0 and 40 0. K-ω SST Turbulence model is used with Ansys Fluent as CFD software. The wing model is analyzed at four different Turbulence intensity levels of 2%, 5%, 10% and 15% and the results are tabulated. Pressure plot and Mach number plot of wing at symmetric section is shown at 0 0 and 4 0 AOA and at different operating speeds of 0.7 and 0.9Mach. High altitude environment conditions are considered for this analysis since the commercial aircraft and defence trainer aircrafts are meant to operate at high altitudes. Also an overview of the Swept wing flow instabilities and flow transitions are briefed in this paper.

- by Dr P K Dash and +1
- •
- Aeronautical Engineering, Aeronautics and aerospace

In this paper, the system requirements for the integration of Remotely Piloted Aircraft Systems (RPAS) in controlled airspace regions are discussed. The specificities in terms of Air Traffic Management (ATM) level of service, jurisdiction for deconfliction duties and prevalent traffic characteristics are analysed to support the identification of operational and equipage requirements for RPAS developers. Communication, Navigation, Surveillance, ATM and Avionics (CNS+A) equipment play an essential role in airspace regions characterised by high levels of Air Traffic Services (ATS) and a higher probability of traffic conflicts. A denser route structure and a more frequent occurrence of traffic conflicts mandate high CNS performance, as the deconfliction by ATM crucially relies on accurate and reliable CNS information. Notwithstanding, the reduced jurisdiction of aircraft in deconfliction duties also offers an opportunity to RPAS developers, as it relieves the requirements for on-board expert processing.

- by Roberto Sabatini and +2
- •
- Robotics, Aerospace Engineering, Mobile Robotics, Autonomous Robotics

This paper presents an energy-optimal guidance and control strategy for 4-dimensional (4D) Trajectory-Based Operations (TBO) in the descent phase, supporting the development of 4D Human-Machine Interface (HMI) formats. The vertical guidance strategy uses multi-phase optimal control techniques based on point-mass aircraft dynamics to determine an energy-optimal descent profile fulfilling prescribed time constraints, additionally generating a set of control inputs which can be passed to the control module. The control strategy is decomposed into attitude and time-and-energy (T&E) components. The attitude control module corrects for cross-track deviations from the nominal profile previously calculated by the guidance algorithm, while the T&E control module corrects for the along-track distance and total energy deviations from the nominal profile. A virtual energy term is introduced which allows the control module to compensate for time deviations from the 4D trajectory. The proposed T&E guidance and control modules are verified through a number of representative case studies, showing that the proposed guidance and control modules allow the aircraft to follow a T&E-optimal 4D trajectory and to recover from deviations in the initial energy states. A prototype HMI is subsequently introduced to present the recommended control inputs to the pilot, also supporting assisted energy management in 4D descent operations.

Internal combustion engine resemble an air pump, the more air that flows through it, the more the horsepower it produces. Therefore, the control of the air inlet flows investigation. To know how each flow characteristics; Air Pressure inlet, Air Temperature intake, and Theoretical Airflow rate calculation largely affect the performance of reciprocating engines. The purpose of this article published the result of an experiment. The airflow system. The experiment was conducted using FSA Bosch engine analyzer. Where air intake temperature, pressure, and theoretically calculated airflow rate is obtained. The experiment process repeated at different configuration. Air configuration measured by using additional electric air blower flow in through the intake manifold to observe and obtain any alteration in the engine performance.

Hybrid-Electric Propulsion Systems (HEPS) have emerged as a promising area of research in aerospace engineering as they combine the complementary advantages of internal combustion and electric propulsion technologies while limiting the environmental emissions. Despite the promising benefits, the insufficient energy densities and specific energies of electrical storage devices are major challenges as they induce severe weight and volume penalties. Significant opportunities are nonetheless emerging thanks to optimised propulsive profiles, energy harvesting techniques and more electric aircraft technologies. To support further research on hybrid electric aircraft, the aim of this study is to develop a HEPS retrofit design methodology for existing Remotely Piloted Aircraft Systems (RPAS). The implemented HEPS models use power state variables, allowing more accurate predictions of energy converter efficiency than with power-based approaches. Data from commercially available products is introduced and a case study is presented assuming a reference RPAS platform and performing parametric studies for traditional, electric and hybrid configurations. Range and endurance performances are investigated in depth and the most significant dependencies on design parameters are analysed. The results suggest that HEPS technology represents a viable trade-off solution in small-to-medium size RPAS, promoting the mitigation of noxious and greenhouse emissions while providing adequate range and endurance performance.

- by Roberto Sabatini and +1
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- Electrical Engineering, Electronic Engineering, Aerospace Engineering, Energy Economics

This invited keynote paper addresses contemporary issues in Air Traffic Management (ATM) focusing on the crucial challenge currently faced by the aviation industry: enhancing safety, efficiency and environmental sustainability of the sector in an era of steady air traffic growth. The aim is to foster opportunities for industrial innovation and multidisciplinary research collaboration in areas of strategic interest such as future systems for Air Traffic Flow Management (ATFM), Dynamic Airspace Management (DAM) and cooperative/non-cooperative surveillance, towards establishing a coherent framework for the evolution of the ATM sector. Taking the move from SESAR / Clean Sky and NextGen top-level operational and technical requirements, the paper presents integrated CNS+A system architectures implementing 4D Trajectory Optimisation (4DTO) algorithms, data link communications and enhanced surveillance technologies, as well as adaptive forms of Human-Machine Interface and Interaction (HMI 2), allowing the automated negotiation and validation of aircraft intents for safer and more efficient ATM operations. As an integral part of this CNS+A evolutionary process, specific requirements for Remotely Piloted Aircraft Systems (RPAS) cooperative/non-cooperative Detect-and-Avoid (DAA) are being addressed in order to allow the safe and unrestricted access of RPAS to all classes of airspace.

ABSTRACT
This book examines Newton's argument for universal gravity and his application of it to resolve the problem of deciding between geocentric and heliocentric world systems by measuring masses of the Moon, Jupiter Planet observed in Moroto,Uganda. Sir Isaac Newton's inferences from phenomena realize an ideal of empirical success that is richer than prediction. To achieve this rich sort of empirical success a theory needs, not only to accurately predict the phenomena it purports to explain, but also, to have those phenomena accurately measure the parameters which explain them. Newton's method aims to turn theoretical questions into ones which can be empirically answered by measurement from phenomena. Newton employs theory mediated measurements to turn data into far more informative evidence than can be achieved by confirmation from prediction alone. Propositions inferred from phenomena are provisionally accepted as guides to further research
This methodology, guided by its rich ideal of empirical success, supports a conception of scientific progress that does not require construing it as progress toward Laplace's ideal limit of a final theory of everything and is not threatened by the classic argument against convergent realism. Newton's method endorses the radical theoretical transformation from his theory to Einstein's theory of relativity. It is strikingly realized in the development and application of testing frameworks for relativistic theories of gravity. In addition, it is very much at work in cosmology today. These propositions described patterns of motion, generalised from observations of the Mercury planet,Earth and moon. It has been noted by many commentators, however, that these do not seem to fit any standard definition of 'phenomenon'. 1 Some have argued that Newton's labelling was mistaken, while others have argued that Newton was using the label 'phenomenon' to avoid using the term 'hypothesis', which would mark his work as speculative, rather than experimental (for the early modern distinction between experimental and speculative philosophy. I argue that Newton's choice of label was appropriate, albeit unconventional. Firstly, drawing on Bogen and Woodward's (1988) distinction between data, phenomena and theories, I Ariny Amos argue that Newton's phenomena performed a specific function: they isolated explanatory targets.
In experimental philosophy [science], we develop our theories from the phenomena we observe, and afterwards we develop general theories for all similar phenomena by inductive reasoning. This was how the laws of motion and gravitation of Planets in Astrology, Astronomical objects in Astrology were Original was Observed ,discovered in, 6th,/Nov/2011, Mwanza Tanzania , , East Africa,This book comprises Introduction

The design, development, test and evaluation of Unmanned Aerial Systems (UAS) are evolving to meet the requirements for integration into civil airspace. These requirements fall under the umbrella of Communications, Navigation, Surveillance and Air Traffic Management (CNS/ATM), the framework for the evolution of next-generation ATM systems. To meet these requirements, improved/specific formats and functions have to be developed for UAS to allow interoperability within current manned and unmanned platform operations. Additionally, greater system autonomy will afford UAS operators the higher levels of control required for airspace integration. Appropriate human-machine interfaces (HMI) are necessary to complement operator performance as well as to prevent human error and automation surprise. The design of such interfaces is still undergoing fluid change. This paper discusses the different modes of UAS operation and outlines the corresponding cognitive demands for each mode. In manned-unmanned aircraft coordinated operations, unanticipated mode transitions are likely to lead to operator mode confusion and have serious safety implications. Appropriate transitions between operating modes are identified for operational safety and efficiency. To achieve such transitions, the paper proposes a cognitive interface to assess, in real-time, the operator's performance and mental state. Such assessment can support in driving mode transitions, which augment the operator's situational awareness, stress, mental work-load and fatigue levels.

- by Roberto Sabatini
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- Electronic Engineering, Robotics, Aerospace Engineering, Cognitive Psychology
- by Roberto Sabatini
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- Robotics, Aerospace Engineering, Aeronautical Engineering, GPS Applications

The paper deals with the study of aerodynamics of small Unmanned Aerial Vehicle for the purpose of reconnaissance which usually carries payloads like Camera. The two wing setup is termed as Tandem Aircraft. Researchers authenticated that tandem wing setup provides better aerodynamic efficiencies at low Reynolds Number compared to conventional. The airfoil used in experimental study is NACA 651-212. The scaled model was tested in the wind tunnel to study the flight behavior and the results have been compared with the value obtained from the computational analysis using Ansys fluent. The prototype interior structure was fabricated with light weight and higher strength glass fiber and multigrain wood. The skin was made of polyester fabric. Field test with various conditions were done. The results were efficient enough that the study further investigated to use of light energy as a power source of the aircraft, which in turn can provide increased mission hours. Abstract-The paper deals with the study of aerodynamics of small Unmanned Aerial Vehicle for the purpose of reconnaissance which usually carries payloads like Camera. The two wing setup is termed as Tandem Aircraft. Researchers authenticated that tandem wing setup provides better aerodynamic efficiencies at low Reynolds Number compared to conventional. The airfoil used in experimental study is NACA 65 1-212. The scaled model was tested in the wind tunnel to study the flight behavior and the results have been compared with the value obtained from the computational analysis using Ansys fluent. The prototype interior structure was fabricated with light weight and higher strength glass fiber and multigrain wood. The skin was made of polyester fabric. Field test with various conditions were done. The results were efficient enough that the study further investigated to use of light energy as a power source of the aircraft, which in turn can provide increased mission hours.

- by Rajesh Kumar and +1
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- Aerospace Engineering, Unmanned Aerial Vehicles, Aeronautics and aerospace
- by Alessandro Gardi and +2
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- Aerospace Engineering, Optimal Control, Aviation, Aeronautics and Aerospace Operations
- by Subramanian Ramasamy and +1
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- Aerospace Engineering, Aeronautical Engineering, Aviation, Aviation Safety

Sandwich panels are increasingly used in aircraft structures due to their high specific bending stiffness and hence excellent buckling stability. The objective of this work is to find rough sizing process of a composite sandwich panel incorporating multi-scale modelling techniques to substantiate structural capability of each level of test pyramid, and find a minimum number of tests required to validate the approaches. The numerical analysis of such hybrid structures by means of the finite element method (FEM) requires specific strategies regarding the degree of homogeneity of each component. The common modelling approach for solid laminate of carbon fibre reinforced plastics (CFRP) structures using an extended layered shell element formulation can also be applied in modelling of sandwich panels in the global FE-model. The sandwich core, which is thicker compared to the solid laminate CFRP skins, can be formulated as an additional layer between the two face skin layers. For more detailed modelling of the sandwich structure, e.g. a cut out of the global FE model (GFEM), a solid shell approach can be applied. Both of the monolithic skins are idealised using layered shell, while the sandwich core is represented by solid elements. For a hard foam core the solid elements are assigned to the core system according to their type, isotropic material for unreinforced foam or homogenised, anisotropic properties for a reinforced foam core system. The homogenised mechanical properties of the reinforced foam core can be determined using analytical or numerical approaches, in which for a numerical approach the textile profile or needles shaped foam reinforcements are modelled with shell and beam elements respectively. With some modifications the meso-mechanical FE-model can further be used e.g. through the application of explicit FEM for the determination of an impact damage or using the virtual crack closure technique (VCCT) method and a higher level of FE discretisation to assess the growth behaviour of damages. The non-linear FE analyses show a good agreement with the recorded panel deformations.

- by ichwan zuardy
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- Mechanical Engineering, Aerospace Engineering, Mechanics, Structural Engineering

Introduction to Stellar Parallax and Stellar Distance Corrections from Military to Public Sector Science

- by Millennium Twain
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- Aerospace Engineering, Space Sciences, Radio Astronomy, Observational Astronomy

Provision of GNSS Avionics Based Integrity Augmentation (ABIA) in Unmanned Aerial Vehicles (UAV) Sense-and-Avoid (SAA) architectures has the potential to provide an integrity-augmented SAA solution suitable for cooperative and non-cooperative scenarios where GNSS is used as the primary source of navigation and/or surveillance data (e.g, employing ADS-B). In this paper, we evaluate the opportunities offered by this integration, proposing a novel architecture that maximizes the synergies between ABIA and SAA functionalities in UAV applications. The performance of this Integrity-Augmented SAA (IAS) architecture was evaluated by simulating manned/unmanned platforms with different dynamics in representative cooperative and non-cooperative scenarios. The numerical results demonstrate that the proposed IAS architecture is capable of performing high-integrity conflict detection and resolution when GNSS is used as the primary source of navigation and/or surveillance data.

- by Roberto Sabatini
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- Aerospace Engineering, Aeronautical Engineering, Electronics, GPS Applications

Whereas current aerospace Human-Machine Interfaces and Interactions (HMI2) are mostly static in their behaviour/appearance and require direct input from human operators, innovative HMI2 concepts are being proposed which allow for multimodal interactions or sense the functional state of human operators and dynamically adapt the level of automation. In particular, to facilitate trust between the human and machine, such systems need sensors that can reliably detect changes in the operator state. However, a number of environmental factors can affect the sensor's accuracy and precision. When used together with other novel sensors, eye tracking has a significant potential to enhance the adaptiveness of aerospace HMI2. This paper presents the activities carried out to quantify the uncertainty associated with eye tracking equipment available in the Avionics and Air Traffic Management (ATM) systems laboratory of RMIT University, which is being used to support the development of Cognitive HMI2. The presented methodology is used to characterise its measurement uncertainty based on a number of considerations, including the calibration error as well as gaze angle in static and dynamic conditions. The uncertainty associated with the eye tracker is used for error budgeting of a Cognitive HMI2 system which employs fuzzy logics to infer operator cognitive states based on eye tracking inputs.