Showing papers on "Propulsion published in 2014"

Rotating detonation wave propulsion: Experimental challenges, modeling, and engine concepts

Abstract: Rotating detonation engines (RDEs), also known as continuous detonation engines, have gained much worldwide interest lately. Such engines have huge potential benefits arising from their simplicity of design and manufacture, lack of moving parts, high thermodynamic efficiency and high rate of energy conversion that may be even more superior than pulse detonation engines, themselves the subject of great interest. However, due to the novelty of the concept, substantial work remains to demonstrate feasibility and bring the RDE to reality. An assessment of the challenges, ranging from understanding basic physics through utilizing rotating detonations in aerospace platforms, is provided.

Advanced High-Power-Density Interior Permanent Magnet Motor for Traction Applications

Abstract: Electric drive systems, which include electric machines and power electronics, are a key enabling technology for advanced vehicle propulsion systems that reduce the petroleum dependence of the ground transportation sector. To have significant effect, electric drive technologies must be economical in terms of cost, weight, and size while meeting performance and reliability expectations. This paper will provide details of the design, analysis, and testing of an advanced interior permanent magnet (PM) machine that was developed to meet the FreedomCAR 2020 specifications. The 12-slot/10-pole machine has segmented stator structure equipped with fractional-slot nonoverlapping concentrated windings. The rotor has a novel spoke structure/assembly. Several prototypes with different thermal management schemes have been built and tested. This paper will cover the test results for all these prototypes and highlight the tradeoffs between the various schemes. Due to the high machine frequency (~1.2 kHz at the top speed), detailed analysis of various loss components and ways to reduce them will be presented. In addition, due to the high coolant inlet temperature and the fact that the machine is designed to continuously operate at 180 °C, detailed PM demagnetization analysis will be presented. The key novelty in this paper is the advanced rotor structure and the thermal management schemes.

Ultrasound-modulated bubble propulsion of chemically powered microengines.

Abstract: The use of an ultrasound (US) field for rapid and reversible control of the movement of bubble-propelled chemically powered PEDOT/Ni/Pt microengines is demonstrated. Such operation reflects the US-induced disruption of normal bubble evolution and ejection, essential for efficient propulsion of catalytic microtubular engines. It offers precise speed control, with sharp increases and decreases of the speed at low and high US powers, respectively. A wide range of speeds can thus be generated by tuning the US power. Extremely fast changes in the motor speed (<0.1 s) and reproducible “On/Off” activations are observed, indicating distinct advantages compared to motion control methods based on other external stimuli. Such effective control of the propulsion of chemically powered microengines, including remarkable “braking” ability, holds considerable promise for diverse applications.

A Supervisory Power-Splitting Approach for a New Ultracapacitor–Battery Vehicle Deploying Two Propulsion Machines

Abstract: Electrification of performance vehicles brings several challenges, such as the necessity of high-power sources, which can satisfy the power requirements during acceleration and efficiently retrieve energy during deceleration without performance and life cycle deterioration of such sources. In addition, the limited space under the hood for these vehicles eliminates the possibility of utilizing large volume high-power propulsion machines. This paper proposes a fuzzy logic supervisory wavelet-transform frequency decoupling-based energy management strategy implemented on a new powertrain deploying two propulsion machines rated at different powers with a hybrid battery/ultracapacitor (UC) energy storage system (ESS). The proposed control and energy management strategy guarantees that battery and UC provide the base and transient-free powers, respectively, while state of charge (SOC) of UC is maintained at an optimal value. The torque demand is split among the propulsion machines by solving the formulated unconstrained optimization problem. With the proposed hybrid ESS and energy/power decoupling strategy, power density of the ESS can be increased, vehicle performance can be improved, and battery lifetime can be prolonged.

NASA Langley Distributed Propulsion VTOL Tilt-Wing Aircraft Testing, Modeling, Simulation, Control, and Flight Test Development

Abstract: Control of complex Vertical Take-Off and Landing (VTOL) aircraft traversing from hovering to wing born flight mode and back poses notoriously difficult modeling, simulation, control, and flight-testing challenges This paper provides an overview of the techniques and advances required to develop the GL-10 tilt-wing, tilt-tail, long endurance, VTOL aircraft control system The GL-10 prototype's unusual and complex configuration requires application of state-of-the-art techniques and some significant advances in wind tunnel infrastructure automation, efficient Design Of Experiments (DOE) tunnel test techniques, modeling, multi-body equations of motion, multi-body actuator models, simulation, control algorithm design, and flight test avionics, testing, and analysis The following compendium surveys key disciplines required to develop an effective control system for this challenging vehicle in this on-going effort

Selecting the Best Electric Machines for Electrical Power-Generation Systems: High-performance solutions for aerospace More electric architectures.

Abstract: The electric machines (EMs) for high-performance electrical power-generation systems (EPGSs) play a significant role in the modern aerospace and military industries. This is particularly true in the area of More Electric Architecture (MEA) for aircraft, spacecraft, and military ground vehicles. The commercial aircraft business is moving toward no-bleed air environmental control systems, variable-frequency and dc power-distribution buses, and electrical actuation. A typical example is the Boeing 787 platform. The next-generation Boeing narrow-body airplane (the replacement for the 737) and the Airbus replacement for the A320 will most likely use MEA. Some ?military ?aircraft already use MEA for both primary and secondary flight control. Military ground vehicles have migrated toward hybrid electric technology. In those cases, the main propulsion is performed by electric drives. This demonstrates that substantial demand has arisen for improved electric power-generation performance. Future space vehicles will require electric drives for thrust-vector and flight-control actuation, demanding more high-quality electric power. These systems must be more robust and will offer greatly reduced operating costs and improved safety compared with Space Shuttle hardware.

Microfabricated electrospray emitter arrays with integrated extractor and accelerator electrodes for the propulsion of small spacecraft

Abstract: Microfabricated electrospray thrusters could revolutionize the spacecraft industry by providing efficient propulsion capabilities to micro and nano satellites (1–100 kg). We present the modeling, design, fabrication and characterization of a new generation of devices, for the first time integrating in the fabrication process individual accelerator electrodes capable of focusing and accelerating the emitted sprays. Integrating these electrodes is a key milestone in the development of this technology; in addition to increasing the critical performance metrics of thrust, specific impulse and propulsive efficiency, the accelerators enable a number of new system features such as power tuning and thrust vectoring and balancing. Through microfabrication, we produced high density arrays (213 emitters cm−2) of capillary emitters, assembling them at wafer-level with an extractor/accelerator electrode pair separated by micro-sandblasted glass. Through IV measurements, we could confirm that acceleration could be decoupled from the extraction of the spray—an important element towards the flexibility of this technology. We present the largest reported internally fed microfabricated arrays operation, with 127 emitters spraying in parallel, for a total beam of 10–30 µA composed by 95% of ions. Effective beam focusing was also demonstrated, with plume half-angles being reduced from approximately 30° to 15° with 2000 V acceleration. Based on these results, we predict, with 3000 V acceleration, thrust per emitter of 38.4 nN, specific impulse of 1103 s and a propulsive efficiency of 22% with <1 mW/emitter power consumption.

Misconceptions of Electric Propulsion Aircraft and Their Emergent Aviation Markets

Abstract: Over the past several years there have been aircraft conceptual design and system studies that have reached conflicting conclusions relating to the feasibility of full and hybrid electric aircraft. Some studies and propulsion discipline experts have claimed that battery technologies will need to improve by 10 to 20 times before electric aircraft can effectively compete with reciprocating or turbine engines. However, such studies have approached comparative assessments without understanding the compelling differences that electric propulsion offers, how these technologies will fundamentally alter the way propulsion integration is approached, or how these new technologies can not only compete but far exceed existing propulsion solutions in many ways at battery specific energy densities of only 400 watt hours per kilogram. Electric propulsion characteristics offer the opportunity to achieve 4 to 8 time improvements in energy costs with dramatically lower total operating costs, while dramatically improving efficiency, community noise, propulsion system reliability and safety through redundancy, as well as life cycle Green House Gas emissions. Integration of electric propulsion will involve far greater degrees of distribution than existing propulsion solutions due to their compact and scale-free nature to achieve multi-disciplinary coupling and synergistic integration with the aerodynamics, highlift system, acoustics, vehicle control, balance, and aeroelasticity. Appropriate metrics of comparison and differences in analysis/design tools are discussed while comparing electric propulsion to other disruptive technologies. For several initial applications, battery energy density is already sufficient for competitive products, and for many additional markets energy densities will likely be adequate within the next 7 years for vibrant introduction. Market evolution and early adopter markets are discussed, along with the investment areas that will fill technology gaps and create opportunities for the effective, near-term electric aircraft products. Without understanding both the context of how electric propulsion will integrate into the vehicle system, and evolve into the market place it is likely that electric propulsion will continue to be misunderstood.

Hydrodynamic analysis of flapping-foil thrusters operating beneath the free surface and in waves

Abstract: Oscillating wings are investigated as unsteady thrusters, augmenting ship's overall propulsion in waves. Flapping propulsor's heave is induced by ship's motions, while pitching motion is set by an active control mechanism. For the detailed investigation of the free-surface effects, a two-dimensional panel method is developed for the hydrodynamic analysis of the flapping hydrofoil. The instantaneous angle of attack is influenced by foil's oscillatory motion and the incident waves. We consider moderate submergence and speed, permitting us to approximately neglect effects of breaking waves and cavitation, and linearize the free-surface boundary conditions and the trailing vortex wake dynamics. Numerical calculations are presented concerning the performance of the developed BEM over a range of motion parameters and compared against other methods and experimental data. Our analysis indicates that significant efficiency is achieved under optimal operating conditions and the free surface effects cannot be neglected. In the presence of waves the thrust coefficient is observed to raise well above its value in infinite domain, with maximum gain reaching 20%, for appropriate selection of the parameters. The present method could serve as a useful tool for the assessment, preliminary design and control of the studied system, extracting energy from sea waves for marine propulsion.

Rotary-wing drone with gearless-drive and fast-mounting propellers

Abstract: Each propulsion unit of the drone comprises a propeller ( 20 ) and a rotary-cage synchronous electric motor whose stator is connected to the drone body. The propulsion unit in of the gearless type, the rotor of the motor being rotationally integral with the propeller hub ( 24 ). The rotor is integral with an upper flange ( 56 ) extending in a radial plane with respect to the axis of rotation. Reversible means are provided for the fast coupling of the propeller to the rotor, implementing studs ( 62 ) with an enlarged head ( 66 ) formed on the flange, which cooperate with homologous curvilinear buttonholes ( 32 ) formed on the hub. The switching from the decoupled position to the locked position is operated by relative rotation of the propeller hub with respect to the flange by a fraction of a turn, in an opposite direction with respect to the direction of rotation of the motor.

Initial Skill Acquisition of Handrim Wheelchair Propulsion: A New Perspective

Abstract: To gain insight into cyclic motor learning processes, hand rim wheelchair propulsion is a suitable cyclic task, to be learned during early rehabilitation and novel to almost every individual. To propel in an energy efficient manner, wheelchair users must learn to control bimanually applied forces onto the rims, preserving both speed and direction of locomotion. The purpose of this study was to evaluate mechanical efficiency and propulsion technique during the initial stage of motor learning. Therefore, 70 naive able-bodied men received 12-min uninstructed wheelchair practice, consisting of three 4-min blocks separated by 2 min rest. Practice was performed on a motor-driven treadmill at a fixed belt speed and constant power output relative to body mass. Energy consumption and the kinetics of propulsion technique were continuously measured. Participants significantly increased their mechanical efficiency and changed their propulsion technique from a high frequency mode with a lot of negative work to a longer-slower movement pattern with less power losses. Furthermore a multi-level model showed propulsion technique to relate to mechanical efficiency. Finally improvers and non-improvers were identified. The non-improving group was already more efficient and had a better propulsion technique in the first block of practice (i.e., the fourth minute). These findings link propulsion technique to mechanical efficiency, support the importance of a correct propulsion technique for wheelchair users and show motor learning differences.

Flight Physics: Essentials of Aeronautical Disciplines and Technology, with Historical Notes

Abstract: Preface 1 History of Aviation 1.1 Introduction 1.2 Early history and the invention of ballooning 1.3 The period between 1799 and 1870 1.4 The decades between 1870 and 1890 1.5 From 1890 until the Wright Flyer III 1.6 European aviation between 1906 and 1918 1.7 Aviation between the world wars 1.8 Development after 1940 Bibliography 2 Introduction to Atmospheric Flight 2.1 Flying - How is that possible? 2.2 Static and dynamic aviation 2.3 Forces on the aeroplane 2.4 Lift, drag and thrust 2.5 Properties of air 2.6 The earth's atmosphere 2.7 The standard atmosphere 2.8 Atmospheric flight Bibliography 3 Low-Speed Aerodynamics 3.1 Speed domains and compressibility 3.2 Basic concepts 3.3 Equations for steady flow 3.4 Viscous flows 3.5 The boundary layer 3.6 Flow separation and drag 3.7 Shape and scale effects on drag Bibliography 4 Lift and Drag at Low Speeds 4.1 Function and shape of aeroplane wings 4.2 Aerofoil sections 4.3 Circulation and lift 4.4 Aerofoil section properties 4.5 Wing geometry 4.6 High-aspect ratio straight wings 4.7 Low-aspect ratio wings 4.8 The whole aircraft Bibliography 5 Aircraft Engines and Propulsion 5.1 History of engine development 5.2 Fundamentals of reaction propulsion 5.3 Engine efficiency and fuel consumption 5.4 Piston engines in aviation 5.5 Gas turbine engine components 5.6 Non-reheated turbojet and turbofan engines 5.7 Turboprop and turboshaft engines 5.8 Gas turbine engine operation 5.9 Propeller performance Bibliography 6 Aeroplane Performance 6.1 Introduction 6.2 Airspeed and altitude 6.3 Equations of motion for symmetric flight 6.4 Steady straight and level flight 6.5 Climb and descent 6.6 Gliding flight 6.7 Cruising flight 6.8 Take-off and landing 6.9 Horizontal steady turn 6.10 Manoeuvre and gust loads Bibliography 7 Stability and Control 7.1 Flying qualities 7.2 Elementary concepts and definitions 7.3 Tail surfaces and flight control 7.4 Pitchingmoment of aerofoils 7.5 Static longitudinal stability 7.6 Dynamic longitudinal stability 7.7 Longitudinal control 7.8 Static lateral stability 7.9 Dynamic lateral stability 7.10 Lateral control 7.11 Stalling and spinning Bibliography 8 Helicopter Flight Mechanics 8.1 Helicopter general arrangements 8.2 Hovering flight 8.3 The rotor in level flight 8.4 Flight performance 8.5 Stability and control Bibliography 9 High-Speed Flight 9.1 Complications due to the compressibility of air 9.2 Compressible flow relationships 9.3 Speed of sound and Mach number 9.4 Flow in a channel 9.5 Shock waves and expansion flows 9.6 High-subsonic speed 9.7 Transonic speed 9.8 Supersonic speed 9.9 Supersonic propulsion 9.10 Performance and operation Bibliography A Units and Dimensions B Principles of Aerostatics Index

Rotational propulsion enabled by inertia

Abstract: The fluid mechanics of small-scale locomotion has recently attracted considerable attention, due to its importance in cell motility and the design of artificial micro-swimmers for biomedical applications. Most studies on the topic consider the ideal limit of zero Reynolds number. In this paper, we investigate a simple propulsion mechanism --an up-down asymmetric dumbbell rotating about its axis of symmetry-- unable to propel in the absence of inertia in a Newtonian fluid. Inertial forces lead to continuous propulsion for all finite values of the Reynolds number. We study computationally its propulsive characteristics as well as analytically in the small-Reynolds-number limit. We also derive the optimal dumbbell geometry. The direction of propulsion enabled by inertia is opposite to that induced by viscoelasticity.

Methods and apparatus for a distributed airborne wireless communications fleet

Abstract: Embodiments of methods and apparatus for providing distributed airborne wireless communications are provided herein. In some embodiments, a communication fleet includes: an airborne communication payload subdivided into multiple payload sections; and a plurality of airborne platforms each including a payload section, wherein each airborne platform comprises an airframe, a propulsion system, a power system, and flight control electronics, wherein the propulsion system is configured to provide propulsion power and thrust to maintain level flight, ascend, descend and maneuver the airborne platform, wherein the power system provides electrical power to the propulsion system, the flight control electronics, and the payload section, and wherein the flight control electronics provide capability to control a position, speed, and flight pattern of the airborne platform.

Velocity Fluctuations in Helical Propulsion: How Small Can a Propeller Be.

Abstract: Helical propulsion is at the heart of locomotion strategies utilized by various natural and artificial swimmers. We used experimental observations and a numerical model to study the various fluctuation mechanisms that determine the performance of an externally driven helical propeller as the size of the helix is reduced. From causality analysis, an overwhelming effect of orientational noise at low length scales is observed, which strongly affects the average velocity and direction of motion of a propeller. For length scales smaller than a few micrometers in aqueous media, the operational frequency for the propulsion system would have to increase as the inverse cube of the size, which can be the limiting factor for a helical propeller to achieve locomotion in the desired direction.

Mitigating power fluctuations in electrical ship propulsion using model predictive control with hybrid energy storage system

Abstract: Shipboard electric propulsion systems experience large power and torque fluctuations on their drive shaft due to propeller rotational motions and waves. This paper explores new solutions to address the fluctuations by integrating a hybrid energy storage system (HESS) and exploring coordinated power management. A propeller and ship dynamic model, which captures the underlying physical behavior, is established to support the control development and system optimization. Given the fact that both high and low frequency contents exist in the power fluctuations, a combination of battery pack and ultracapacitor bank is proposed, coordinated control is developed, and performance is evaluated in different sea conditions. Simulation results show that the proposed HESS with model predictive control provides substantial benefits in terms of reducing fluctuation and sustaining self-operation, compared to other solutions that involve batteries or ultracapacitors alone. Moreover, our analysis shows that the benefits of HESS are achievable only through both effective power management and device coordination.

ESTCube-1 nanosatellite for electric solar wind sail in-orbit technology demonstration

Abstract: This paper presents the mission analysis, requirements, system design, system level test results, as well as mass andpower budgets of a 1-unit CubeSat ESTCube-1 built to perform the first in-orbit demonstration of electric solar wind sail (E-sail)technology. The E-sail is a propellantless propulsion system concept that uses thin charged electrostatic tethers for turning themomentum flux of a natural plasma stream, such as the solar wind, into spacecraft propulsion. ESTCube-1 will deploy and chargea 10 m long tether and measure changes in the satellite spin rate. These changes result from the Coulomb drag interaction with theionospheric plasma that is moving with respect to the satellite due to the orbital motion of the satellite. The following subsystemshavebeendevelopedtoperformandtosupporttheE-sailexperiment: atetherdeploymentsubsystembasedonapiezoelectricmotor;an attitude determination and control subsystem to provide the centrifugal force for tether deployment, which uses electromagneticcoils to spin up the satellite to one revolution per second with controlled spin axis alignment; an imaging subsystem to verify tetherdeployment, which is based on a 640 × 480 pixel resolution digital image sensor; an electron gun to keep the tether at a highpositive potential; a high voltage source to charge the tether; a command and data handling subsystem; and an electrical powersubsystem with high levels of redundancy and fault tolerance to mitigate the risk of mission failure.

Design of a robot for in-pipe inspection using omnidirectional wheels and active stabilization

Abstract: This paper discusses the design of a vehicle for in-pipe inspection using omnidirectional wheels and active stabilizing control. A novel propulsion mechanism is discussed using omnidirectional wheels (or omni-wheels) is presented which allows direct control of the orientation in the pipe. This paper will show the development and evaluation of a prototype model. Rapid prototyping techniques have been used in this proof-of-principle.

Hybrid gas turbine propulsion system

Abstract: A hybrid aerodynamic thrust system as a prime mover for aircraft or other high-speed vehicles. An arrangement of dual thrust resources to alternately accommodate low and high airspeed regimes. Electromotive force is used in lieu of hot section power turbines to achieve engine air compression or alternately perform thrust work at low velocities.

Validation Ice Crystal Icing Engine Test in the Propulsion Systems Laboratory at NASA Glenn Research Center

Abstract: The Propulsion Systems Laboratory (PSL) is an existing altitude simulation jet engine test facility located at NASA Glenn Research Center in Cleveland, OH It was modified in 2012 with the integration of an ice crystal cloud generation system This paper documents the inaugural ice crystal cloud test in PSL--the first ever full scale, high altitude ice crystal cloud turbofan engine test to be conducted in a ground based facility The test article was a Lycoming ALF502-R5 high bypass turbofan engine, serial number LF01 The objectives of the test were to validate the PSL ice crystal cloud calibration and engine testing methodologies by demonstrating the capability to calibrate and duplicate known flight test events that occurred on the same LF01 engine and to generate engine data to support fundamental and computational research to investigate and better understand the physics of ice crystal icing in a turbofan engine environment while duplicating known revenue service events and conducting test points while varying facility and engine parameters During PSL calibration testing it was discovered than heated probes installed through tunnel sidewalls experienced ice buildup aft of their location due to ice crystals impinging upon them, melting and running back Filtered city water was used in the cloud generation nozzle system to provide ice crystal nucleation sites This resulted in mineralization forming on flow path hardware that led to a chronic degradation of performance during the month long test Lacking internal flow path cameras, the response of thermocouples along the flow path was interpreted as ice building up Using this interpretation, a strong correlation between total water content (TWC) and a weaker correlation between median volumetric diameter (MVD) of the ice crystal cloud and the rate of ice buildup along the instrumented flow path was identified For this test article the engine anti-ice system was required to be turned on before ice crystal icing would occur The ice crystal icing event, an uncommanded reduction in thrust, was able to be turned on and off by manipulating cloud TWC A flight test point where no ice crystal icing event occurred was also duplicated in PSL Physics based computational tools were successfully used to predict tunnel settings to induce ice buildup along the low pressure compression system flow path for several test points at incrementally lower altitudes, demonstrating that development of ice crystal icing scaling laws is potentially feasible Analysis of PSL test data showed that uncommanded reduction in thrust occurs during ice crystal cloud on operation prior to fan speed reduction This supports previous findings that the reduction of thrust for this test article is due to ice buildup leading to a restricted airflow from either physical or aerodynamic blockage in the engine core flow path

Solar Electric Propulsion for Discovery-Class Missions

Abstract: This paper offers a user-centric consolidation and comparison of the full range of government and commercial solar electric propulsion options available in the near term for primary propulsion on deep-space science missions of the class commonly proposed to NASA’s Discovery program. Unlike previous papers, this work does not emphasize feasibility from a mission-analysis perspective. Rather, it emphasizes requirements uniquely imposed by competitively reviewed cost-capped mission proposals, for which system-level flight heritage and cost credibility can trump sheer performance and mission capture. It describes criteria that mission architects and review boards can use to select and evaluate electric propulsion systems, provides descriptions of viable government and commercial electric propulsion system options, describes the modifications needed to adapt commercial electric propulsion systems to deep space, and discusses appropriate methods for costing commercial-based electric propulsion systems. It concl...

Conceptual Design of the Joby S2 Electric VTOL PAV

Abstract: Recent advances in electric propulsion technologies have opened up new design options for aircraft through the application of distributed electric propulsion. Notably, many vertical takeoff and landing configurations that were previously impractical or impossible now have the potential to become viable aircraft that provide transformational capabilities. One such configuration, a two-seat fully-electric 200 mph personal aircraft with 200 mile range, is being designed by Joby Aviation to meet unaddressed commuting and transportation desires. The distributed nature of the propulsion system enables unprecedented redundancy and simplicity in a VTOL aircraft, resulting in increased safety and lower maintenance; additionally, other aspects of this configuration reduce noise signatures and drastically decrease energy usage, and the 200 mph cruise speed is significantly faster than comparable existing small VTOL aircraft. Design goals are introduced to constrain the design space to practical and viable configurations. The conceptual design of this aircraft entailed the use of design tools of various fidelity, including vortex-lattice analysis, blade-element momentum theory codes, and full Navier-Stokes CFD analysis. A sizing code integrated results from these tools along with semi-empirical mass estimates to perform mission analysis and analyze trade-offs between various design variables. The resulting aircraft design demonstrates the potential of these new electric propulsion technologies to enable viable and attractive new VTOL configurations that can provide new capabilities to private pilots.

Turboelectric distributed propulsion benefits on the N3-X vehicle

Abstract: Purpose – The purpose of this article is to present a summary of recent study results on a turboelectric distributed propulsion vehicle concept named N3-X. Design/methodology/approach – The turboelectric distributed propulsion system uses multiple electric motor-driven propulsors that are distributed on an aircraft. The power to drive these electric propulsors is generated by separately located gas turbine-driven electric generators on the airframe. To estimate the benefits associated with this new propulsion concept, a system analysis was performed on a hybrid-wing-body transport configuration to determine fuel burn (or energy usage), community noise and emissions reductions. Findings – N3-X would be able to reduce energy consumption by 70-72 per cent compared to a reference vehicle, a Boeing 777-200LR, flying the same mission. Predictions for landing and take-off NOX are estimated to be 85 per cent less than the Tier 6-CAEP/6 standard. Two variants of the N3-X vehicle were examined for certification noi...