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This paper presents a study dedicated to the development of Digital and Smart Tools, based on solved applications of design engineering and reverse engineering. This approach is justified by the fact as well as the need for preparations prior to Composite Additive Manufacturing. Future integration of Digital Smart Tools with Composite Additive Manufacturing will significantly contribute to the efficient and effective support of the green economy, the active, responsible, safe and resilient protection of environment, life and climate. The research involved in this paper contributes to develop Digital and Smart Tools Applications, intended for integrated digital design, development, manufacturing and further predictive maintenance and services, based on robotic systems, extended automatic control, Artificial Intelligence and Machine Learning, including Mathematical Modeling and Numerical Simulations for Performance Prediction at Design Regime and Off-Design Regimes for jet engines, with the best capabilities to generate and integrate improvements, optimizations and potential innovative solutions. This paper presents significant applications of design, concept engineering development and reverse engineering design, as: 1/ the design of a transonic axial compressor rotor blade, 2/ the design of a swept axial compressor rotor, 3/ concept design engineering developments in case of a swept fan rotor blade, 4/ concept design developments and reverse engineering in case of a HP axial compressor rotor blade, part of Spey 512-14 DW turbofan engine, 5/ reverse engineering design of a Cessna 182 Skylane N223IF light aircraft wheel cover. In line with Europe´s vision for sustainable aviation, this research study and INCAS´ TGA Project "Technological Development Platform for "Green" Technologies in Aviation and Ecological Manufacturing with Superior Added Value; TGA - Technologies for Green Aviation" will significantly contribute to the Green Deal, as a production center using "Green" Technologies in aviation and ecological manufacturing, as well as collaborative developer of Digital and Smart Tools for Composite Additive Manufacturing.

This study shows how to generate images and compose images in the modern simulator room by starting multiple work sessions running at the same time so that all active server stations and the station to connect to are continuously displayed. Each server handles specific functions of the simulation process and runs a dedicated software application for its specific functions. For a supervised flight simulator, the following functions need to have dedicated applications: 1) Flight Dynamics Simulation, 2) Graphical projection, 3) Cockpit and Flight instrumentation simulation and integration, 4) Supervisor station. Out of these functions, Graphical projections and Cockpit and Flight instrumentation and integration require the most computational resources. Simulators need to present the view from a cockpit which requires a field of view of at least 180 degrees. This requires at least three displays usually in the form of projectors. In legacy implementations due to computational bottlenecks, each projector needed a dedicated computer. Similarly, the Cockpit and Flight instrumentation simulation requires usually upwards of 100 flight instrument simulations and embedded processors to be managed. In legacy implementations, one computer is needed for each piloting station. In recent implementations due to the increased performance of multi-core processors, many of these functions can be handled by single computers: the flight dynamics simulation and graphical projection functions can currently be handled by a single computer, similarly, all Cockpit and Flight instrumentation simulation and integration can be handled by another computer. Thus, a minimum of three servers are required to ensure full functionality of supervised simulation using modern computing systems.

In this paper, uncertainty is included in the extended framework of global air traffic both through the action of the wind and through the incomplete determination of the aerodynamic coefficients and the inevitable imprecision involved in the execution of ATC instructions. In order to study the air conflict detection process in detail, the possibility of potential conflicts must be evaluated, considering the current state of the international airspace, and taking into account the uncertainty in calculating the future position of the aircraft. A mathematical model for predicting potential aerial conflicts is necessary for this objective. In a probabilistic framework, the mathematical model thus created could be either an empirical distribution of future aircraft positions in space or a dynamic model, such as a stochastic differential equation, that describes the movement of the aircraft and implicitly defines a distribution for the position’s future of the aircraft/ future aircraft positions. Based on the prediction model, aircraft flight safety matrices can be evaluated. The mathematical methods applied in the Detection and Resolution of Air Traffic Conflicts - CDR involve a wide range of fields, but also the appropriate modeling of physical systems such as airplanes, the codification of mathematical algorithms for conflict detection, as well as the properly applied procedures for resolving potential air conflicts.

This study presents the flight plan data related to aircraft performance and is tested against the aircraft performance database. The Significant Meteorological Information Reports - SIGMET will be generated by the system according to the selected turbulence areas by attaching different AIS data to an exercise that can change the simulation objectives. The exercise must be assigned to one or more courses to be able to attach meteorological data when viewing a data recording; changes can be made to the aircraft as in a normal exercise run, while the other instructions will be loaded from the recorded data file. A data recording is airspace dependent, changing the airspace can make the data recording fail during playback. Video Recording is only available for the RADAR Simulator. A video recording can be made at any time during a simulation session; a data recording can be selected only at the beginning of the simulation session and cannot be started during the simulation session; if the simulator is integrated with the Voice Communication System and the audio channels, then a sound recording window will automatically pop-up. For this study, an ideal case, for the configuration presentation we will assume that the 3D Tower Simulator is composed of 4 LCD/Projectors to create the out-of-the-window view, 180 degrees, 2 Pseudo-Pilots, and 1 Supervisor/FEEDER Position. The 4 image generators will be provided by SIM01, SIM02, SIM03, and SIM04. The Pseudo-Pilots positions will be provided by SIM05 and SIM06. The Supervisor/Feeder Position will be provided by SIM07. For the Tower Controller Working Positions, we will provide the following information displays: DE – Flight Data Equipment/Clearance Delivery, MET – Meteorological Information, LCP –Lights Control Panel, and a RADAR Image. Station SIM08 will be used. Stations SIM01, SIM02, SIM03, and SIM04 are equipped with one large LCD Display or a Projector; Stations SIM05 and SIM07 are equipped with 2 monitors, one for the RADAR Image and the other one for the bird-eye view over the airport; Station SIM06 is equipped with one monitor for the bird-eye view over the airport; Station SIM08 is equipped with 4 monitors providing all necessary information for the Tower Controller Working Positions. SIM07, as presented above, is the FEEDER/SUPERVISOR for the RADAR Simulator, the approach sector is “TMA” and the application will be started on the second monitor, the first monitor is used for the 3D Tower Simulator. SIM07 is also FEEDER/SUPERVIZOR for the 3D Tower Simulator, the station function will be “3DTWR” and the sector will be the previously created 3D Tower configuration, “TOWER”. On SIM08 will add a RADAR Image for the Tower Controller Working Positions, sector is “TMA”, the application will be started on monitor 4, and the station function is “TWR”. Usually, for an aircraft departing from an airport inside an approach sector, the first owner will be the tower until passing the maximum flight level/ altitude for the tower, the second owner will be the approach sector and the third owner will be the en-route sector. In this case, the tower sector has power over the approach sector, and the en-route sector, the approach sector has power over the en-route sector. The outside FIR sectors will be used in the determination of the next en-route sector, for coordination purposes. If the VFR points do not appear on the RADAR Map after the “DRAW” button has been pushed, use the “MAP MENU” – “VFR” button. The aircraft performance database is not airspace structure dependent. When a new airspace structure is created the aircraft performance database will remain unchanged.

This paper presents the main objective of Air Traffic Management Systems – ATMS that is to achieve optimized performance in terms of aviation safety and the enhancement of the current air transport system, through the in-depth study of the complex integration of all advanced technologies regarding air traffic monitoring, aeronautical communications on-board computers, display and control systems within the extended framework of Air Traffic Services - ATS. The Flight Management System - FMS is indispensable for flight planning, air navigation, flight performance management, aircraft guidance on the flight path and continuous monitoring of the progress during flight. The FMS is the device used by the flight crew to select various modes of flight control via the flight control computer - FCM and to display flight plans and other flight data via the Multi-Functional Control Display Unit - MCDU. The flight path is monitored by the MCDU and the Electronic Instrument System – EIS. The in-depth study of Air Transport Efficiency when applying air traffic service operational analysis and trajectory determination methods to identify key areas of Air Traffic Management inefficiencies and to prioritize and implement appropriate optimization methods are presented and analyzed in detail in this paper.

Aircraft Health Management Technology for jet engines represents a very important problem, since it develops a large impact on reducing the engine life cycle costs, improving the fuel efficiency, increasing the engines durability and life cycle. This technology is high-end and, in order to enable an improved level of performance that far exceeds the current one, propulsion systems must comply with terms of reducing harmful emissions, maximizing fuel efficiency and minimizing noise, while improving system’s affordability and safety. Aircraft Health Management Technology includes multiple goals of aircraft propulsion control, diagnostics problems, prognostics realized, and their proper integration in control systems. Modern control for Aircraft Health Management Technology is based on improved control techniques and therefore provides improved aircraft propulsion system performances. The study presented in this paper approaches a new concept, of attractive interest currently, that is the intelligent control; in this context, the Health Management of jet engines is crucial, being focused on engine controllers which are designed to match certain operability and performance constraints. Automated Engine Health Management has the capacity to significantly reduce the maintenance effort and propulsion systems’ logistical footprint. In order to prioritize and resolve problems in the field of support engineering there are required more detailed data on equipment reliability and failures detection and management; the equipment design, operations and maintenance procedures and tooling are also very important.

The Fuel Management Systems for civil aircrafts have a direct impact on the airlines profitability, competitiveness and sustainability, because the fuel represents the highest cost for airlines, on average 32% of overall operating costs; extra costs can frequently be taken into account, due to the increase in time of approach and straight-in landing versus circle to land maneuver. The core philosophy of the Fuel Management Systems, targeted to aircraft safety, must be focused on the most important aspects regarding the efficient operation of an airline and its proper management expressed in terms of efficacy, efficiency and effectiveness; an actual concern of great interest is the adequate fuel management. In this paper, a thorough study was carried on based on the state of art detailed investigation, with numerical simulations for significant case studies which are relevant for the implementation of robust fuel management processes in order to increase the internal efficiency and reduce the overall costs. In this paper, fuel management solutions and specific mode of their implementation are presented. The benefits of Fuel Aircraft Management Systems are multiple related and refer to: minimizing the costs, reducing the workload, improving internal and external data sharing, reducing unnecessary communications, controlling fuel costs, making better decisions, improving cash flow and creating a more cohesive approach to the Fuel Aircraft Management System. The applications of Fuel Aircraft Management System are beneficial to the aviation industry, and particularly, this study brings a significant contribution to the topic, i.e. advances in Fuel Aircraft Management System.

For most compressor flows, the existence of turbulent shear stresses is essential to compensate and overcome the adverse pressure gradients without separation. The performance of compressor improves as the turbulent stresses get stronger relative to the laminar viscous stresses, which become significant as the Reynolds number increases. The methods used to design subsonic axial flow compressors and fans are based on correlations such as deviation angle vs. incidence angle to obtain the expected performance for a particular blade profile. In this paper, compressor models that are used frequently in controller designs are described and the effect of the assumptions on the prediction capability of these models is explained. The control concepts used to maintain and therefore grant the stable operation are presented and monitored, as well as an outline of sensors, actuators and automatic controllers is given. The survey concludes that the behavior of a compressor system subsequent to instability onset is reasonably understood but the considered models can not describe all types of instabilities encountered. There comes the recommendation that for a better understanding of the mechanisms behind the onset of such instabilities, refinements as new improvements of the existing models are require, which may give insights into new automatic control methods.

The active control for centrifugal compressor systems consists in using, monitoring and managing the sensors to detect fluid disturbances, the actuators to introduce desired perturbations and a suitable controller to determine the optimal actuator actions using the sensor information. The object of an interesting centrifugal compressor design is to obtain the most air through a given diameter compressor, with a minimum number of stages while maintaining high efficiencies and aerodynamic stability over the operating range. The high efficiency of the axial compressor system decreases dramatically when used in small high-pressure applications, especially due to the large relative tip clearance. In addition, the high centrifugal force, dominating the pressure rise, results in a superior operability and the short axial length of the centrifugal compressor offers rotor-dynamic multiple advantages. These qualities allow the centrifugal compressor system to be used as the last stage of a high-pressure compressor of an aero engine as well as turbo pump assemblies used in liquid-propelled rocket engines.

This paper presents a numerical simulation for a different aircraft, based on the specific aircraft data that can be incorporated in the model and the equations of motions which can be consequently solved. The aircraft flight design involves various technical steps and requires the use of sophisticated software having modeling and simulation capabilities. Within the flight simulation model, the aerodynamic model can be regarded as the most complex and most important. With appropriate aerodynamic modeling the aerodynamic forces and moments acting on the aircraft's center of gravity can be numerically solved with accuracy. These forces and moments are further used to solve the equations of motion. The development of control and computing technology makes it possible for advanced flight control strategy. The advanced control techniques tend to make the control design and their implementation much more complicated with more control loops or channels; in this line, the autopilot of modern aircrafts includes a variety of automatic control systems that aid and support the flight navigation, flight management, and perform the enhancing and/or augmenting of the stability characteristics of the airplane. Therefore in this context it is very important to choose the dynamic that will satisfy the performance and robustness specifications.

This paper explains why the combination of programming codes represents a true engineering tool in aircraft systems investigating. Flight safety and flying quality are extremely important to modern aviation industry. The aircraft responses, which are measured during real flight, are compared to the responses that are obtained from the simulations. Typically, aircraft problems consist in finding the solutions for basic work in all kind of areas, using knowledge from fields of science such as physics, mathematics and computer science. The purpose is to present such problems solved by computer simulations. Some of the advantages of performing numerical simulations are the low risk and low cost involved as compared to performing aircraft experiments. Another major advantage is the physical insight which one can gain in the behavior of the system subjected to different conditions and different values of the characteristic parameters of the aircraft's dynamic performances.

The mechanical guided waves have a wide range of applications in many types of equipment and devices. The fuel level is an important parameter which needs to be monitored for a vehicle which can be a space vehicle, an aircraft or any other. For this purpose mechanical guided waves can be used as they have several major advantages over any other methods. There are a wide ultrasonic sensors used for this purpose but in the most cases the mechanical waves are traveling through air or fuel for measuring their level. In general the wave propagation through a single media at a time is utilized. The method described in this work uses the propagation of the mechanical guided waves through two different media in the same time. The propagating media is the container wall and the other is the fuel. One of the advantages of this method is the reduction of the measurement errors when the incident angle to the fuel level surface is different from 90 degree. These situations could occur when the fuel tank is tilted or when the fuel surface is not flat. This measurement method will not be affected by these conditions.

Following the demands of the design and performance analysis in case of liquid fuel propelled rocket engines, as well as the trajectory optimization, the development of efficient codes, which frequently need to call the Fuel Combustion Charts, became an important matter. This paper presents an efficient solution to the issue; the author has developed an original approach to determine the non-linear approximation function of two variables: the chamber pressure and the nozzle exit pressure ratio. The numerical algorithm based on this two variable approximation function is more efficient due to its simplicity, capability to providing numerical accuracy and prospects for an increased convergence rate of the optimization codes.

Collision prevention strategy in ATM is not only a short-term coordination between safety and efficiency, but also a long-term planning for national policy of airspace and air transportation system. The optimization of system should be based on good command of equipment, staff, procedure and operation restriction to meet the real-time requirement and integrity. Essentially, collision prevention strategy in ATM consists in finding synthetic and effective automatized avoidance methods in order to reduce the possibility of dangerous approach or collision, of which the conflict detection, conflict resolution and resolution trajectory optimization are the key technology. This paper proposes a research on the standard of intelligent prevention of collision, and theory and methodology of its optimization from the systems engineering perspective. This paper describes thoroughly the decision-making procedure of ATC, establishes the optimized target for ATC's decision-making, and puts forward an optimization of conflict detection and conflict resolution between several aircrafts in 4D space. The medium and long term collision prevention strategy through adjusting speed or altitude and short-term collision prevention strategy through adjusting heading makes the intelligent ATC system a perfect one.

This paper is dedicated to the study and analysis of a successfully designed control system in ATM. The aircraft's motion is affected by other factors, besides the pilot controls in the form of external disturbances, such as wind, and internal errors, due to unmodelled dynamics, tracking error and system noise. Navigation equipment tracks the exact real-time location of the aircraft in 4D space and provides feedback to both the pilot in the cockpit and ATC via ADS-B. ATM was expressed as a large, decentralized, dynamic, variable size, infinite horizon, multi-parameter, constrained, nonlinear, non-causal, non-convex, multi-objective, high-dimensionality, hybrid (continuous and combinatorial), optimal control problem. Rapidly increasing growth and demand in CNS/ATM, the advanced scheme for ATM, ADS-B system which is based on digital communication is being implemented in the field of surveillance. ADS-B is a radically new technology that is redefining the paradigm of CNS in ATM today. Automatic Dependent Surveillance-Broadcast (ADS-B) is the next generation air surveillance system which supplants and complements the limitations of conventional radar, since conventional ATM radar systems will reach their limits soon due to the increases in air traffic.

This paper is dedicated to the study and analysis of a successfully designed control system, whose capability should always maintain the stability and performance level in spite of the uncertainties in system dynamics and within the working environment to a certain degree. Design requirements such as gain margin and phase margin in using classical frequency-domain techniques are solely for the purpose of robustness. A constrained optimization is then performed to maximize the robust stability of the closed-loop system to the type of uncertainty chosen, the constraint being the internal stability of the feedback system. In most cases, it would be sufficient to search a feasible controller such that the closed-loop system should achieve certain robust stability. Performance objectives can also be included in the optimization cost function. Elegant solution formulae have been developed, which are based on the solutions of certain Algebraic Riccati Equations.

This paper will analyze the Gust Load Alleviation (GLA) systems which can be used to reduce the effects of atmospheric turbulences generated by wind gusts on vertical acceleration of aircraft. Their purpose is to reduce airframe loads and to improve passenger comfort. The dynamic model of the aircraft is more realistic than a rigid-body model, since it includes the structural flexibility; due to its complexity, such model can make feedback control design for gust load alleviation more challenging. The gust is generated with the Dryden power spectral density model. This kind of model lends itself well to frequency-domain performance specifications in the form of the weighting functions. Two classical analytical representations for the power spectral density (PSD) function of atmospheric turbulence as given by Von Kármán and Dryden, were used. The analysis is performed for a set of specified values for flight velocity and altitude (as test cases), with different gust signals that must be generated with the required intensity, scale lengths and PSD functions.

The purpose of this paper is to study the instability of the dynamic flutter. The justification is expressed by the fact that the occurrence of flutter within the aircraft’s flight envelope results in irreversible structural deformation which consequently leads to serious damage. Therefore the mathematical modeling of this phenomenon and its validation are very important. The instability of the dynamic flutter is characterized by critical speed and critical pulsation of oscillatory movements. In this paper, the quasi-stationary model and the Theodorsen model have been analyzed for calculating the aerodynamic forces and torques, and a comparison of them has been carried out. The fluid-structure coupling is done by rewriting the equations, considering that the forces are given by closed formulas. For the mathematical modeling of the flutter there have been used the p-k and V-g methods based on the Theodorsen model and the quasi-stationary model. In order to modeling the free vortices aerodynamic forces and moments, the equations which describe both the motion of the structure and the fluid flow had to be integrated simultaneously in time. The fluid-structure coupling is considered as a combination of two systems that describe the aeroelastic behavior of the structure.