Browse Topic: Electric aircraft

Items (293)

It’s not only automobiles that are going electric — airplanes are as well! And, to prove that an aircraft can be electrically powered, NASA has developed the X-57 Maxwell, its first all-electric X-plane. The X-57 airplane, currently in the Mod II configuration, is a modified version of the Italian Tecnam P2006T. In place of the usual gasoline-powered motors, the X-57 has two all-electric motors powered by traction batteries. The X-57 Maxwell project has some lofty goals, including lower energy consumption (the X-57’s motors use one-fifth the energy of a gasoline-powered aircraft), reduced emissions, and lower noise during flight.

Energy Scavenging from Passengers for Powering Low-energy Electronics in Aircrafts

2022-26-125505/26/2022

With the ever increasing demand for aerial modes of transportation and reduction of different harmful emissions from these modes of transportation has led to demand for more electric modes of powering these aerial vehicles. In addition to that, the aerospace industry is also looking to make the aircrafts more smart and more connected. This involves increased use of more sensors, ICs and many more micro-electronic components. Even though they look small and consume less electricity, the electric battery which is supposed to be used for aircraft propulsion will require to power up these smaller components as well, which will continue to be a concern as the aircrafts begin using more and more of these components. Hence, a solution is needed to reduce the dependency of micro-electronic components or any other aircraft components used within the aircraft on the electric battery to be used for aircraft propulsion. The concept of Energy Harvesting or Energy Scavenging refers to the capturing

Bajpai, Apoorva

Non-parametric Optimization of Heat Sinks for Power Dense Motor Controllers

2022-26-117505/26/2022

With the future of mobility moving towards electrification there is an ever-increasing demand in both aerospace and automotive industry for achieving higher power density in inverters, controllers, etc. In the aviation industry, the trend of more electric aircraft has resulted in transition from central to zonal architecture. In zonal architecture, controller units are kept close to the actuator systems and localized harsh bay conditions, space constraints coupled with the necessity for high power density has made thermal management a challenging task. This warrants a need for exploring innovative cooling techniques to manage the dissipated heat. This paper focuses on a liquid cooled thermal management system for power dense applications. The heatsink design presented here is a pin fin arrangement staggered to induce swirling flow, which has been proven to enhance heat transfer. The traditional heatsink optimization involves creating a design of experiments (DoE) with parameters like

Bhardwaj, Divyanshu, Datta, Sauradeep, Borkar, Kishor

Method and Apparatus for Data Processing and Acquiring High Speed Data of Electric Drive System using RS485 and MATLAB Functionality Based Developed Serial Reader Graphical User Interface Tool

2022-26-117605/26/2022

The Electric Drive System implemented in more electric aircraft architecture cover one of the applications like engine start up driving the starter generator machine in motoring mode for engine startup and voltage regulation from the starter generator in power generation mode. Electric Drive System undergoing the mode transitions through operating mode change requirements to perform all the operation defined by application either motor or generator operation. In the development of these controls, the conventional modeling and tuning will become tedious and time consuming. Multiple software updates and model updates are required. Our proposed method ties the models and allows temporary controls parameters update loads to the Electric Drive System for the real time testing. Electric Drive System software modifications are required to investigate field issues while integrating Starter Generator machine with the end application. The investigation requires high speed data acquisition of the

SAKINALA, KUMAR, Kashireddy, Davendar, Mani, Sivaraman, Cheng, Louis

Integration of Smart Sensors in more Electric Aircraft

2022-26-115205/26/2022

This paper discusses the role of smart sensor in more electric aircraft where systems are more integrated and complex than ever. Today traditional sensors are being replace with smart sensors but have limited usage in Aircraft, this paper will provide an insight to use of smart sensors and their role in electrical aircraft. This will also bold out the advantage of smart sensors over the traditional sensors and conclude with its merits and demerits

Chopra, Taruna, Waghmare, Piyush

Potential Applications of Fuel Cells in Air Mobility

2022-26-121605/26/2022

The climate change impact due to increased greenhouse gas emissions like carbon dioxide (CO2), methane, nitrous oxide (NOx) and ozone etc. has been immense over the years and causing increase in temperatures of the earth’s surface and global warming. Recently, there is a significant effort to reduce the emissions especially after Paris agreement in 2015. There are several research initiatives across the globe to reduce the emissions like NOx, CO2 and other harmful substances. The air mobility also contributed to the increased greenhouse gases due to CO2 and NOx. This paper presents the potential applications of fuel cells for air mobility that includes helicopters, hybrid electric aircrafts and all electric aircrafts to achieve the reduced emissions and reduced fuel consumption. The objective of this paper is to take a broad view of how fuel cell technology works, various types of existing technologies and their potential applications and challenges for air mobility vehicles in terms

Kari, Sreedhar, Kumar, Ravi

An approach to designing Hybrid Electric System for Aircraft

2022-26-115905/26/2022

The Aviation industry has come a long way in terms of being energy efficient and with an objective to reduce carbon footprint is currently transitioning from traditionally fuel operated to Hybrid Electric system with a goal to completely move to All Electric system. Hybrid Electric system uses fuel as one of the sources and battery or hydrogen fuel cells as an alternate source of energy. All the existing aircraft manufacturers are investing heavily in designing either Hybrid or All electric powered aircrafts. This paper provides an approach to design a Hybrid Electric System for an aircraft by means of a case study and provides guidance on selection criteria for key components involved in design of Hybrid Electric System for an aircraft.

Mehta, Prashant

SAE TOMORROW TODAY: Empowering Superheroes: Emergency eVTOL Aircraft from Start-Up Jump Aero

1317311/28/2021

In emergency situations, every second counts - but long distances to rural areas and congested city traffic often increase the time it takes to transport a patient to a hospital. Jump Aero is mobilizing eVTOL aircraft as a solution to cut emergency response time in half and save thousands of lives. Co-founders Carl Dietrich, President/Chief Designer, and Katerina Barilov, Head of Business Development, discuss their passion for the Jump Aero mission. Hear more about how electric aircraft can reduce the time it takes to get a responder on the scene, why their EMTs are required to learn how to fly an airplane, and how their commitment to engage with EMS communities builds partnerships and trust. Stay up to date on the latest news from Jump Aero: https://www.jumpaero.com/

Hineman, Marcie

SAE TOMORROW TODAY: Mark Moore's New Start-Up Making Noise with Quieter Electric Aircraft

1316810/22/2021

A new age of flight is taking shape from brilliant engineers who are redefining how lower carbon emissions, minimal noise pollution and reduced maintenance costs can work together. Mark Moore's newest venture, Whisper Aero, is combating busier skyways with a new electric thruster design that reduces noise to a near-imperceptible level. Moore, a former NASA engineer and Uber Elevate executive, discusses the need for sustainable eVTOL, eCTOL and eSTOL aircraft, how eliminating noise will aid public adoption, and why he decided to set up camp in Crossville, Tenn. Stay updated on the latest news from Whisper Aero: https://www.whisper.aero/

Hineman, Marcie

Experimental Study of Aluminum Metal Foam Material on Heat Transfer Performance

2021-26-023909/22/2021

Abstract: Electrification is one of the megatrends across the industries, like electric vehicles, more electric aircraft, electric vehicles etc. which needs advancement in power electronics component technology. As technology advances in miniaturization of power electronics, thermal-management issues threaten to limit the performance of these devices. These may force designers to derate the device performance and ultimately these compromise in design may increase the size, weight of the application. One of the technologies capable of accomplishing these goals employs a class of materials know as metal foam. Metal foams are lightweight cellular materials inspired by nature. The main application of metal foams can be grouped into structural and functional and are based on several excellent properties of the material. Structural applications take advantage of the light-weight and specific mechanical properties of metal foam. Functional applications are based on a special functionality

Makhe, Sunil, Dandekar PhD, Chinmaya

Design of a Novel 2-Stroke SI Engine for Hybrid Light Aircraft

2021-01-117909/21/2021

The trend of powertrain electrification is quickly spreading from the automotive field into many other sectors. For ultra-light aircraft, needing a total installed propulsion power up to 150 kW, the combination of a specifically developed internal combustion engine (ICE) integrated with a state-of-the-art electric system (electric motor, inverter and battery) appears particularly promising. The dimensions and weight of ICE can be strongly reduced (downsizing), so that it can operate at higher efficiency at typical cruise conditions; a large power reserve is available for emergency maneuvers; in comparison to a full electric airplane, the hybrid powertrain makes possible to fly at zero emissions for a much longer time, or with a much heavier payload. On the other hand, the packaging of a hybrid powertrain into existing aircraft requires a specific design of the thermal engine, that must be light, compact, highly reliable and fuel efficient. The last aspect has a direct impact on the

Caprioli, Stefano, Rinaldini, Carlo, Mattarelli, Enrico, Savioli, Tommaso, Scrignoli, Francesco

Systematic Approach to an Improved Electrical Power System Architecture for a Future More Electric Airplane

2021-01-003403/02/2021

Commercial transport airplane technology is moving toward a next generation More Electric Airplane (MEA) in order to further improve airplane performance and efficiency. Electricity is seeing increased use for power generation, transmission and energy storage in place of less efficient pneumatics and hydraulics. The MEA is also a technology enabler for new environmentally friendly electrical generation and storage devices such as fuel cells, batteries and super capacitors. Successful use of these new technologies requires systematically analyzing the interface of these technologies with each other, and with other systems that impact overall airplane performance, efficiency, weight and reliability. In this paper, incremental changes in the airplane power system will be analyzed. With each of these changes, the benefits to the electrical power system and the impact that each change has on the airplane will be estimated. These incremental changes and their impact will be incorporated into

Breit, Joseph Sherman

Improved Energy Management System for Airplane Electrical Power

2021-01-000803/02/2021

As commercial transport aircraft progress toward a future More Electric Airplane (MEA) there are numerous opportunities to improve energy management of the electrical power system. Improved energy management of the airplane electrical power system not only has the potential to decrease the weight and improve the efficiency of the system, but also to improve system stability and reliability. This paper analyzes re-architecting of an MEA airplane electrical power system in order to better manage the current electrical loads. It also considers the use of new sources of power generation and energy storage that would enable improved energy management for a new improved MEA such as fuel cells, batteries and super capacitors. The analysis uses data associated with current methods for calculating electrical loads and evaluates how the energy management of those loads can be improved with a better understanding of their usage in various flight phases, their criticality, and their power quality

Breit, Joseph Sherman

Pyrofuse Modeling for eVTOL Aircraft DC Protection

2021-01-004103/02/2021

Contemporary trends are leading towards the electrification of aircraft for urban mobility applications. Accordingly, there is a high demand for advancements in light-weight, high voltage technologies to realize these new aircraft types. Driven by recent developments in the automotive industry, hybrid Pyrofuse protection devices have emerged as one such new candidate technology. Pyrofuses offer rapid clearance of fault currents, reduced cost and weight when compared to conventional mechanical breakers. In addition, Pyrofuses have the ability to tune the time-current curve to fit the application’s fault response characteristics. However, Pyrofuses are non-resettable devices whose exclusive use for electrical protection could present potential operational hazards and certification challenges in aerospace applications. Model-based analysis will be critical in supporting this evaluation. Accordingly, this paper offers the first complete design methodology to transiently model Pyrofuse

Altouq, Shadan, Fong, Kenny, Norman, Patrick, Burt, Graeme

SAE TOMORROW TODAY: 2020 Recap: How Aerospace Innovation Takes Flight

1293302/26/2021

Imagine calling for an Uber and having an eVTOL show up to take you to your destination. Imagine traveling at supersonic speeds without the booming and disruptive noise. Imagine taking off in an airplane that has absolutely no pilot. On this last installment of our 2020 Recap Series, we're not only imagining this innovation, we're exploring how aerospace and mobility leaders are making it a reality. Our guests throughout the year have come from leading companies across industries including aircraft design, aerospace and autonomy. On this episode discover the advances in commercial travel and how Siemens Digital Industries Software is saving you time, explore how Uber Elevate is changing the game for rideshare, and how Aerion is solving the noise issue of supersonic travel.

Hineman, Marcie

High-Efficiency Megawatt Motor

TBMG-3813712/01/2020

Innovators at NASA Glenn Research Center have designed a High-Efficiency Megawatt Motor (HEMM), a wound-field partially superconducting machine. The HEMM implements a combination of superconducting and non-superconducting elements, along with an integrated cryocooler, to achieve some of the benefits of a superconducting motor without the need for an external cryogenic system.

Battery Improvement Enhances Electric Flight and Long-Range Electric Cars

TBMG-3779810/01/2020

In the pursuit of a rechargeable battery that can power electric vehicles (EVs) for hundreds of miles on a single charge, scientists have endeavored to replace the graphite anodes currently used in EV batteries with lithium metal anodes. But while lithium metal extends an EV's driving range by 30 to 50%, it also shortens the battery's useful life due to lithium dendrites — tiny, treelike defects that form on the lithium anode over the course of many charge and discharge cycles. Dendrites also short-circuit the cells in the battery if they make contact with the cathode.

Redesigning the Systems Engineering Process to Speed Development of E-Propulsion Aircraft

TBMG-3788510/01/2020

The e-propulsion aircraft industry is a hotbed of activity and investment. However, converting these exciting concepts into viable commercial solutions presents one of the most significant challenges in the history of aviation. To streamline the development process and accelerate time to market, OEMs should consider replacing traditional, silo-based approaches to systems engineering with a model-based strategy that facilitates seamless, real-time collaboration among the entire development team.

Tools for the Conceptual Design of a Stratospheric Hybrid Platform

2020-01-002503/10/2020

CIRA is currently designing a HAPS for Earth Observation and Telecommunications named High Altitude Hybrid Airship. The configurations considered, can generate both aerodynamic and aerostatic forces to balance the weight during the different phases of a mission. The design of a hybrid configuration for stratospheric platforms represents a novelty in itself in the aerospace sector while some hybrid platforms have been proposed only for tropospheric applications. In order to carry out the conceptual design, some design tools have been implemented to rapidly obtain a conceptual layout, which can be used to perform CFD, FEM and stability analysis and, at the same time, to compute the relative platform mass breakdown. The proposed conceptual design process is based on two steps. A first coarse exploration algorithm which, starting from some input parameters, determines the best buoyancy ratio and some overall platform parameters (among others: weight, volume and dimensions) using some semi

Baraniello, Vincenzo Rosario, Persechino, Giuseppe, Borsa, Roberto

Introduction to Control Volume Based Transient Thermal Limit

2020-01-003903/10/2020

Advancement in modern aircraft with the development of more dynamic and efficient technologies has led to these technologies increasingly operated near or at their operation limits. More comprehensive analysis methods based on high-fidelity models co-simulated in an integrated environment are needed to support the full utilization of these advanced technologies. Furthermore, the additional information provided by these new analyses needs to be correlated with updates to traditional metrics and specifications. One such case is the thermal limit requirement that sets the upper bound on a thermal system temperature. Traditionally, this bound is defined based on steady-state conditions. However, advanced thermal management systems experience dynamic events where the temperature is not static and may violate steady-state requirements for brief periods of time. Due to the large thermal time constants for many components, such transient violations may not represent system failure and an

Yeu, Rodney, Deppen, Tim, Raczkowski, Brian, Jones, Nicholas, Walters, Eric, Donovan, Adam, Patnaik, Soumya, Bodie, Mark

Employing the Electrical Digital Twin to Mitigate Compliance Risk in Aerospace

TBMG-3568812/01/2019

Delivering aircraft and various avionics compliant with the latest standards and regulations is increasingly difficult. Today, it’s not uncommon for a single commercial aircraft to comprise hundreds of line-replaceable units, hundreds of miles of wire, and unique configurations throughout all parts of a platform that must meet numerous certification requirements. With increasing electrical system content and complexity, a single change during the design, verification, or compliance process can put the entire program in jeopardy. With the rise in electrification and design complexity, aerospace original equipment manufacturers (OEMs) need to look for new methodologies to mitigate compliance risk.

Facility Focus: NASA John H. Glenn Research Center

TBMG-3569812/01/2019

Originally established as the Aircraft Engine Research Laboratory (AERL) — part of the National Advisory Committee for Aeronautics (NACA) — in 1941, NASA's Lewis Research Center in Cleveland, OH became a national resource for innovations in aircraft engine technology that influenced commercial and military propulsion systems. Lewis Research Center became part of the new National Aeronautics and Space Administration (NASA) in 1958. In 1999, NASA Lewis was renamed the John H. Glenn Research Center at Lewis Field.

Flight Optimization Model on Global and Interval Ranges for Conceptual Studies of MEA Systems

2019-01-190609/16/2019

In development of more electric aircraft applications, it is important to discuss aircraft energy management on various level of aircraft operation. This paper presents a computationally efficient optimization model for evaluating flight efficiency on global and interval flight ranges. The model is described as an optimal control problem with an objective functional subjected to state condition and control input constraints along a flight path range. A flight model consists of aircraft point-mass equations of motion including engine and aerodynamic models. The engine model generates the engine thrust and fuel consumption rate for operation condition and the aerodynamic model generates the drag force and lift force of an aircraft for flight conditions. These models is identified by data taken from a published literature as an example. First, approximate optimization process is performed for climb, cruise, decent and approach as each interval range path. Next, optimization for global

Shibuya, Yotsugi, Oyori, Hitoshi, Sugawara, Hirotaka, Seki, Naoki

Gradationally Controlled Voltage Inverter for More Electric Aircrafts

2019-01-191309/16/2019

The more electric aircraft (MEA) concept has been attracting attention over recent decades to reduce emissions and fuel consumption. In MEAs, many subsystems that previously used hydraulic or pneumatic power have been replaced by electrical systems, and hence the weight of inverters has significant importance. The weight of inverters is largely attributed to passive filters that reduce the derivative of output voltages dv/dt and electromagnetic interference noises caused by common-mode voltages. To reduce the size of passive filters, multilevel inverters with 5 or more voltage steps are preferred. However, classic multilevel inverters have some challenges to achieve these step numbers without using plural dc power supplies that require massive transformers. In this work, a gradationally controlled voltage (GCV) inverter is proposed for MEAs. The GCV inverter can supply gradational quasi-sinusoidal voltages with 7 voltage steps, combining two different voltages from a three-level (main

Kojima, Tetsuya, Sugahara, Masahiro, Shirouchi, Yusuke, Fukumoto, Hisatoshi, Iwata, Akihiko, Oyori, Hitoshi

Preventing Ice Buildup on Electric Aircraft

19AERP08_0408/01/2019

Fuel economy is one of the biggest challenges facing the aviation industry. To overcome these challenges, researchers are working on next generation aviation systems. Next generation aircraft will be either hybrid power, or all-electric power, which would help with fuel consumption. But electric aircraft present challenges in other areas such as the prevention of ice formation. Ice formation on aircraft can degrade the aerodynamic performance significantly by reducing lift while increasing drag. Tech Briefs Media Group (TBMG) editor, Billy Hurley, interviewed researcher Afaq Ahmed Abbasi of Northwestern Polytechnical University's Department of Fluid Mechanics to learn more about these challenges. TBMG: What are the traditional methods of preventing ice formation on aircraft?

Testing of Elastomer Icephobic Coatings in the AIWT: Lessons Learned

2019-01-199406/10/2019

A study has been conducted into icephobic properties of some highly durable “off-the-shelf” elastomer materials using a rotating ice adhesion test rig installed in the NRC’s Altitude Icing Wind Tunnel. This enabled the formation of ice at environmental conditions similar to those experienced during in-flight icing encounters. Initially, the tests indicated some very positive results with ice adhesion shear stress as low as 8KPa. On further examination, however, it became apparent that the test preparation process, in which the samples were cleaned with an ethanol alcohol solution, influenced the results due to absorption and prolonged retention of the cleaning fluid. The uptake of the ethanol alcohol solution by the elastomer was found to be a function of the surface temperature and remained absorbed into the coating during the ice accretion process changing the characteristics of the coating in such a way that led to a reduction in the ice/surface bond strength.

Orchard, David, Chevrette, Gislain, Maillard, Damien, Khoun, Lolei

A Multi-Domain Component Based Modeling Toolset for Dynamic Integrated Power and Thermal System Modeling

2019-01-138503/19/2019

Design of modern aircraft relies heavily on modeling and simulation for reducing cost and improving performance. However, the complexity of aircraft architectures requires accurate modeling of dynamic components across many subsystems. Integrated power and thermal modeling necessitates dynamic simulations of liquid, air, and two-phase fluids within vapor cycle system components, air cycle machine and propulsion components, hydraulic components, and more while heat generation of many on-board electrical components must also be precisely calculated as well. Integration of these highly complex subsystems may result in simulations which are too computationally expensive for quickly modeling extensive variations of aircraft architecture, or will require simulations with reduced accuracy in order to provide computationally inexpensive models. As such, a need for software toolsets with the ability to model complex aircraft architectures with accurate calculations while maintaining high

McCarthy, Patrick Thomas, McCarthy, Kevin, Hasan, Maher, Boyd, Michelle, Chang, Michael, Walters, Eric, Niedbalski, Nicholas

A Predictive Reference Governor for Synchronous Generator Regulation with a Pulsed Constant Power Load

2019-01-137903/19/2019

In this paper, first an analytical model of a synchronous generator with a pulsed constant power load (CPL) is developed and numerically compared with a detailed simulation model. The analytical model is shown to possess good predictive abilities, thus enabling its use for control purposes. Second, the generator has a proportionalintegral (PI) control inner-loop, whose task is to regulate the generator’s output voltage to a desired reference. A novel outer-loop predictive reference governor (PRG) is designed and tested via simulation. The PRG uses the analytical model to predict the output behavior of the generator over a short time window, and continuously modifies the reference given to the inner-loop in order to maintain stringent steady-state requirements, in spite of demanding power requirements at the CPL. Simulation results illustrate the significant performance advantages of using the PRG versus using the inner-loop PI controller alone. The paper also discusses challenges of

Ordonez, Raul, Zumberge, Jon, Hencey, Brandon

Information on Electric Brakes

AIR5937 (Current)02/15/2019

This SAE Aerospace Information Report (AIR) describes the design, operation, and attributes of electrical braking systems for both military and commercial aircraft. At this time, the document focuses only on brakes utilizing electromechanical actuators (EMAs), as that is the present state of the art. As such, the discussions herein assume that EMAs can simply replace the hydraulic actuation portion of typical brake system leaving things such as the wheel and heat sink unchanged. Furthermore, the document provides detail information from the perspective of brake system design and operation. The document also addresses failure modes, certification issues, and past development efforts. Details on the design and control of electric motors, gear train design, ball or roller screw selection are available in the reference documents and elsewhere, but are outside the scope of this document. Other all-electric technologies such as piezoelectric actuation or more exotic methods of applying drag

A-5A Wheels, Brakes and Skid Controls Committee

Reliability Case Analysis of an Autonomous Air Cooling System (AACS) for Aerospace Applications

2018-01-191610/30/2018

Current More Electric Aircraft (MEA) utilize Liquid Cooling Systems (LCS) for cooling on-board power electronics. In such LCS, coolant pipes around the structure of the aircraft are used to supply water glycol based coolant to sink heat from power electronics and other heat loads in the electronic bay. The extracted heat is then transferred to ram air through downstream heat exchangers. This paper presents a reliability examination of a proposed alternative Autonomous Air Cooling System (AACS) for a twin engine civil MEA case study. The proposed AACS utilizes cabin air as the coolant which is in turn supplied using the electric Environmental Control System (ECS) within the MEA. The AACS consists of electrical blowers allocated to each heat load which subsequently drive the outflow cabin air through the heat sinks of the power electronics for heat extraction. No additional heat exchanger is required after this stage in which the heated air is directly expelled overboard. One key

Fong, Chung Man, Norman, Patrick, Seki, Naoki

Power Dissipation Optimization for Solid State Power Control Modules in the Aircraft Secondary Power Distribution System

2018-01-193010/30/2018

In the last two decades, an aerospace industry trend in the secondary power distribution concept has been dominated by power electronics technology which includes power converters and Power Control Modules based on Solid State Power Control (SSPC) switching elements. These Power Control Modules, grouped around microprocessor based controllers and combined in a single electronic chassis, have become a backbone of electrical power distribution systems on all major commercial and military transport aircraft. Due to the resistive properties of the semiconductor-based SSPC devices, whose behaviors can be described as nonlinear functions of ambient operating temperature, power distribution system integration with SSPCs is challenged and heavily affected by operating temperatures and power dissipation limits. Although aircraft compartments where Power Control Modules are located are considered temperature and pressure controlled, high ambient operating temperatures are possible and expected

Novakovic, Neno, Manojlovic, Milorad

Potential Improvements in Turbofan’s Performance by Electric Power Transfer

2018-01-196210/30/2018

Bleeding in engines is essential to mitigate the unmatched air massflow between low and High Pressure (HP) compressors at low speed settings, thus avoiding unstable operation due to surge and phenomena. However, by emerging the More Electric Aircraft (MEA) the engine is equipped with electrical machines on both high and Low Pressure (LP) spools which enables transfer of power electrically from one spool to another and hence provides the opportunity to operate engine core components closer to their optimum design point at off-design conditions. At lower power setting of the engine, HPC speed can be increased by taking power from LP shaft and feeding it to HP shaft which can lead to the removal of the bleeding system which in turn reduces weight and fuel consumption and help to overcome engine instability issues. Fuel consumption can be decreased by decreasing inconsistent thrust with the aircraft mission for flight and ground idle settings. This paper investigates the idea of power

Balaghi Enalou, Hossein, Le-Peuvedic, Jean-Marc, Rashed, Mohamed, Bozhko, Serhiy

Modulation Limit Based Control Strategy for More Electric Aircraft Generator System

2018-01-193710/30/2018

Vector based control strategies have been extensively employed for drive systems, and in recent times to the More Electric Aircraft (MEA) generator based systems. The control schemes should maintain the bus voltage and adhere to the generator system voltage and current limits throughout a wide speed range. Typically, the current limit is prioritised first due to ease of implementation and simple control structure. As a result, the voltage limit can be exceeded due to change in operating conditions or disturbance factors. In flux weakening regions, this may affect the controllability of the power converter and lead to generator system instability. In this paper, an alternative control strategy has been investigated to address this drawback. The proposed control scheme refers to the modulation index limit which is the ratio between the power converter input and output voltages as the voltage limit. The control scheme uses a dynamic limit for the generator reference voltages such that the

Yeoh, Seang Shen, Rashed, Mohamed, Bozhko, Serhiy

Definitions of Test Conditions for High Voltage Aerospace Systems Using the IAGOS Atmospheric Dataset

2018-01-193110/30/2018

Aerospace electrical systems are continuing to increase their voltage levels to meet the on-board power demands of more-electric aircraft (MEA) where hydraulic and pneumatic systems are replaced with electrical equivalents. This trend will only continue as hybrid and all- electric aircraft are developed. These higher power demands require the use of higher voltages and as such it is essential to explore the behaviour of the insulation system in the aerospace environment. This insulation must operate in an environment where the operating temperatures range from 250°C to -65°C, the air pressure is around one tenth of that at ground level and where the levels of humidity and ozone vary rapidly. Understanding the impact of these variables on aircraft high voltage insulation systems is crucial in predicting their behaviour and lifetime. Our work with the IAGOS atmospheric dataset presents worst-case and typical flight environments for higher than expected cruising altitudes, and uses the

Haghighi, Hasti, Cotton, Ian, Gardner, Richard, Sauvage, Bastien

Energetic, Environmental and Range Estimation of Hybrid and All-Electric Transformation of an Existing Light Utility Commuter Aircraft

2018-01-193310/30/2018

Today it is necessary to face the energetic, environmental, and safety-related issues of a significant industrial sector such as aeronautic one. It is a marginal contributor to today global GHG emissions (less than 3%), In any case, the associated impacts grows with the increase of air traffic with annual rate 5%. Consequently, aviation will need to face four fundamental problems for the future: 1 the overall impact of aviation is expected to grow up to 10÷15% of global GHG emissions by 2050; 2 the emissions of pollutants by commercial aviation affects the fragile atmospheric layers in the low stratosphere; 3 the increasing age of the flying fleet deals with increasing maintenance and safety issues; 4 the dependence on fossil fuels relates to problems of geopolitical instability and consequence volatility of prices. Substantial innovations are expected for both reducing energy consumption and environmental impacts of aviation and reducing the age of the fleets. They mostly relate to

Trancossi, Michele, Pascoa, Jose

Dynamic Stability Analysis of High-Speed Traction Drive CVT for Aircraft Power Generation

2018-01-193610/30/2018

The traction-drive integrated drive generator (T-IDG®) has been developed since 1999 to replace current hydrostatic transmission drive generators mounted on Japanese military aircraft. The T-IDG® consists of a generator and a half-toroidal traction-drive continuously variable transmission (CVT), which maintains a constant output speed of 24000 rpm, that is, a 400 Hz AC power supply. To cope with recent trends of more electric aircraft (MEA) and the need for weight reduction, a high-speed traction-drive CVT is advantageous over other transmissions. The torque on the half-toroidal variator is transmitted through multiple power rollers. The equal load sharing among power rollers is typically controlled by a mechanical hydraulic feedback system, whose stability is one of the main issues for the high-speed traction-drive CVT. Previous studies have shown that insufficient damping and stiffness of the mechanical hydraulic feedback system cause self-induced vibration. We found that the support

Matsuda, Kippei, Goi, Tatsuhiko, Tanaka, Kenichiro, Imai, Hideyuki, Tanaka, Hirohisa, Sato, Yasukazu

Transient Stability Analysis of DC Solid State Power Controller (SSPC) for More Electric Aircraft

2018-01-192710/30/2018

The solid state power controller (SSPC) is one of the most important power electronic components of the aircraft electrical power distribution (EPS) systems. This paper presents an architecture of the DC SSPC and provides the mitigation techniques for transient voltage overshoot during its turn-off. The high source side inductance carries breaking current (9xnominal current) just before turnoff and induces large voltage transient across the semiconductor devices. Therefore, the stored inductive energy needs to be dissipated in order to prevent semiconductor switches from over-voltage/thermal breakdown. Three different transient voltage suppression (TVS) devices to reduce voltage stress across switches are included in the paper for detail study. The comprehensive comparison of the TVS devices is presented. In addition, the thermal impact of the TVS devices on the semiconductor switches is also analyzed. Later, the transient simulation model of the SSPC is built in LT-Spice and the

Adhikari, Jeevan, Yang, Tao, Rashed, Mohamed, Bozhko, Serhiy, Zhang, JiaWei, Wheeler, Patrick W.

Aircraft electric propulsion technology review – A shift from turbofan to the ethrust era

2018-36-009609/03/2018

Following the electrification trend observed in the automotive industry, the idea of an electric propulsion aircraft has also drawn attention and investments from a range of aviation industry stakeholders (including the world's largest aerospace companies) focused on both fuel burning reduction and environmental performance improvement (greenhouse gases (GHG), pollutants and noise emissions) potential of electric propulsion technology. Electric propulsion has the potential to provide more efficient, cleaner, quieter and more profitable aviation services, with potential benefits to both airlines and passengers. Furthermore, with its inherent quiet feature, it has also the potential to lead to a reassessment of the role of airports along the world cities, as well as revitalize regional short-haul flights and helps the launch of air service into underserved regions around the world. From a technical perspective , the aviation propulsion electrification strategy might involves the

Barbosa, Fábio Coelho

Design study of high aspect ratio wings for unmanned air vehicles (UAV's)

2018-36-007309/03/2018

The availability of new technologies and the growing interest in the development of autonomous aircraft has created a demand for performance evaluation of aircraft flying at high altitudes over a long period of time for applications such as monitoring, telecommunications, etc. This work presents a study on the use of wings with high aspect ratio for the application in unmanned aircraft, that fly at high altitudes and require great endurance to remain flying as long as possible. With reference to the AeroVironment Helios aircraft, which hit the altitude record in 2001, flying at more than 29,000 meters altitude, a comparison was made between five wings with different wingspan from the aerodynamic and structural point of view. The aerodynamic performance of each wing was calculated and structural design and sizing was performed, assuming that it is the main structural component of the wing. Optimazing each wing aerodynamically and structurally, it was possible to compare wing performance

Hargreaves, Bernardo Oliveira, de Freitas Pinto, Ricardo Luiz Utsch, Frágola, Luciano Magno Barbosa

Novel Turboelectric Aircraft Design

TBMG-2886105/01/2018

NASA Langley Research Center has developed a novel aircraft design that can carry 150+ passengers over a range of 3,500 nautical miles. Key features include a turboelectric propulsion system, twin underwing turbofans, and a rear-fuselage, electrically driven, boundary layer ingesting fan. The design is developed for single-aisle-class aircraft (the largest commercial transport class in the world) to significantly reduce fuel burn compared to current aircraft.

Comparison of Duty-Cycle of a Lithium-Ion Battery for Electric Airplane and Electric Vehicle Applications

2018-01-066604/03/2018

In this study, the duty-cycle of a commercial lithium-ion battery (LIB) for a typical passenger airplane (Bombardier CRJ200) is obtained and compared to the duty- cycle of the same LIB for electric vehicles. For this purpose, the velocity and altitude of the airplane is monitored during a typical flight and the instantaneous mechanical power of the airplane is obtained by modeling. Based on the airplane required power and the characteristics of the LIB, a battery pack is designed for the airplane. Then, the duty-cycle of a LIB cell in the battery pack is yielded. The duty-cycle of the same LIB for a typical electric vehicle is also obtained from modeling based on the Highway Fuel Economy Test (HWFET), New York City Cycle (NYCC) and United States 2006 (US06) drive-cycles. Finally, the duty-cycle of the LIB for two different applications of electric airplane and electric vehicle is compared. The duty-cycles obtained in this study can be employed to study the lifespan of LIBs.

Alhadri, Muapper, Mohammed, Abdul Haq, Farhad, Siamak

Balance of Plant: Integrating PEM Fuel Cells into Aircraft

TI-000211/13/2017

While all-electric aircraft remain at the bleeding edge of the aviation industry, incorporating technologies like proton exchange membrane fuel cells into existing aircraft can result in considerable auxiliary capability with low environmental impact. However, proper consideration must be given to supporting systems to achieve a reliable balance of plant-especially when those systems interface with existing aircraft architectures. The scope of the BoP is to manage and condition the reactant flows to and from the fuel-cell module and to provide power to system components.

A New VTOL Propelled Wing for Flying Cars: Critical Bibliographic Analysis

2017-01-214409/19/2017

This paper is a preliminary step in the direction of the definition of a radically new wing concept that has been conceived to maximize the lift even at low speeds. It is expected to equip new aerial vehicle concepts that aim to compete against helicopters and tilt rotors. They aim achieving very good performance at very low speed (5 to 30 m/s) by mean of an innovative concept of morphing ducted-fan propelled wing that has been designed to maximize the lift force. This paper presents an effective bibliographic analysis of the problem that is a preliminary necessary step in the direction of the preliminary design of the wing. A preliminary CFD evaluation allows demonstrating that the claimed results are in line with the initial expectations. According to the CFD, results it has been produced a preliminary energetic evaluation of the vehicle in a flying car configuration by EMIPS method. Even if the results are still preliminary, they allow evidencing a good energy efficiency of the

Trancossi, Michele, Hussain, Mohammad, Shivesh, Sharma, Pascoa, Jose

Integrated Design of Motor Drives Using Random Heuristic Optimization for Aerospace Applications

2017-01-203009/19/2017

High power density for aerospace motor drives is a key factor in the successful realization of the More Electric Aircraft (MEA) concept. An integrated system design approach offers optimization opportunities, which could lead to further improvements in power density. However this requires multi-disciplinary modelling and the handling of a complex optimization problem that is discrete and nonlinear in nature. This paper proposes a multi-level approach towards applying random heuristic optimization to the integrated motor design problem. Integrated optimizations are performed independently and sequentially at different levels assigned according to the 4-level modelling paradigm for electric systems. This paper also details a motor drive sizing procedure, which poses as the optimization problem to solve here. Finally, results comparing the proposed multi-level approach with a more traditional single-level approach is presented for a 2.5 kW actuator motor drive design. The multi-level

Cheong, Benjamin, Giangrande, Paolo, Wheeler, Patrick, Zanchetta, Pericle, Galea, Michael

Advanced Partial Discharge Testing of 540V Aeronautic Motors Fed by SiC Inverter under Altitude Conditions

2017-01-202909/19/2017

The present paper reports non-electrically intrusive partial discharge investigations on aeronautic and electric vehicle motors fed by SiC inverter drive under variable environmental conditions. A representative test procedure and experimental set-up based on operating aeronautic conditions are essential to ensure the accuracy and reliability of partial discharge test on aircraft systems to make informed decisions on insulation system design choice. The aim of this paper is to demonstrate the feasibility of partial discharge test of the insulation system on a different type of motor under such conditions, both electrically and environmentally. To do so, the paper will start by detailing the innovative experimental set-up to be used in the study. It mainly consists in a high-voltage (1000V) inverter drive using SiC components to provide fast rise time surges. A vacuum chamber is used to simulate altitude while the association of non-intrusive sensors, analog filtering and wavelet based

BILLARD, Thibaut, Abadie, Cedric, Taghia, Bouazza

Aircraft Fuel System Design Using 1D and 3D Methods: An Enabler for Thermal Management

2017-01-203909/19/2017

Thermal management on aircraft has been an important discipline for several decades. However, with the recent generations of high performance aircraft, thermal management has evolved more and more into a critical performance and capability constraint on the whole aircraft level. Fuel continues to be the most important heat sink on high performance aircraft, and consequently the requirements on thermal models of fuel systems are expanding. As the scope of modeling and simulation is widened in general, it is not meaningful to introduce a new isolated modeling and simulation capability. Instead, thermal models must be derived from existing model assets and eventually enable integration across several physical domains. This paper describes such an integrated approach based on the Modelica Fuel System Library and the 3DExperience Platform. It combines 1D and 3D methodology and delivers capabilities normally limited to complex and time-consuming CFD computations at the speed and convenience

Sielemann, Michael, Lee, Changsoo, LeBrun, Victor-Marie, Ahn, Chiwoo, Colleoni, Arnaud, Lee, Dongkyu, Lee, JeongSeok, Nguyen, Anh, Proelss, Katrin, Yoon, Hyon Min

Exploitation Strategies of Cabin and Galley Thermal Dynamics

2017-01-203709/19/2017

The thermal inertia of aircraft cabins and galleys is significant for commercial aircraft. The aircraft cabin is controlled by the Environment Control System (ECS) to reach, among other targets, a prescribed temperature. By allowing a temperature band of ± 2 K instead of a fixed temperature, it is possible to use this thermal dynamic of the cabin as energy storage. This storage can then be used to reduce electrical peak power, increase efficiency of the ECS, reduce thermal cooling peak power, or reduce engine offtake if it is costly or not sufficiently available. In the same way, also the aircraft galleys can be exploited. Since ECS and galleys are among the largest consumers of electrical power or bleed air, there is a large potential on improving energy efficiency or reducing system mass to reduce fuel consumption of aircraft. This paper investigates different exploitation strategies of cabin and galley dynamics using modelling and simulation. Modelica models of the thermal and the

Schlabe, Daniel, Zimmer, Dirk, Pollok, Alexander

The Flying Carpet: Aerodynamic High-Altitude Solar Reflector Design Study

2017-01-202609/19/2017

Our concept studies indicate that a set of reflectors floated in the upper atmosphere can efficiently reduce radiant forcing into the atmosphere. The cost of reducing the radiant forcing sufficiently to reverse the current rate of Global Warming, is well within reach of global financial resources. This paper summarizes the overall concept and focuses on one of the reflector concepts, the Flying Carpet. The basic element of this reflector array is a rigidized reflector sheet towed behind and above a solar-powered, distributed electric-propelled flying wing. The vehicle rises above 30,480 m (100,000 ft) in the daytime by solar power. At night, the very low wing loading of the sheets enables the system to stay well above the controlled airspace ceiling of 18,288 m (60,000 ft). The concept study results are summarized before going into technical issues in implementation. Flag instability is studied in initial wind tunnel experiments. This has forced evolution of the concept to one similar

Komerath, Narayanan, Hariharan, Shravan, Shukla, Dhwanil, Patel, Sahaj, Rajendran, Vishnu, Hale, Emily

Steady State Characterization of Arcing in 540 V dc Distribution Systems

2017-01-203509/19/2017

As applications in aerospace, transportation and data centers are faced with increased electric power consumption, their dc operating voltages have increased to reduce cable weight and to improve efficiency. Electric arcs in these systems still cause dangerous fault conditions and have garnered more attention in recent years. Arcs can be classified as either low impedance or high impedance arcs and both can cause insulation damage and fires. Low impedance arcs release lots of energy when high voltage becomes nearly shorted to ground. High impedance arcs can occur when two current-carrying electrodes are separated, either by vibration of a loose connection or by cables snapping. The high impedance arc decreases load current due to a higher equivalent load impedance seen by the source. This complicates the differentiation of a high impedance arc fault from normal operation. The topics of high impedance arc generation; characterization and modeling; and detection have all been studied in

Bauer, Eric C., Niassati, Nima, Brothers, John, Troth, John, Hensal, Jeff, Wang, Jin, Schweickart, Daniel, Grosjean, Dennis

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