Browse Topic: Electric aircraft

Items (305)
An electric vertical take-off and landing aircraft (eVTOL) is a variety of vertical take-off aircraft driven by electric power. This work proposed a new boundary condition control method to investigate the take-off and landing process of eVTOL, which is under the conditions of a typical atmospheric boundary layer. The spatial flow field information, especially the height-dependent atmospheric crosswind velocity profile, will be projected on the temporal axis and superimposed with the existing time-dependent unsteady conditions. Taking a 4-axis eVTOL as an example, computational fluid dynamics (CFD) simulations based on unsteady Reynolds-Averaged Navier-Stokes (uRANS) and rigid body motion (RBM) are carried out with proposed unsteady boundary conditions. The loads and surrounding flow field of the aircraft are obtained, while the vortical structures are further identified and discussed. Notably, the impact of atmospheric boundary layer on the aerodynamic force of eVTOL during vertical
Wei, HuanxiaJia, ChundongShi, YongweiJia, QingXia, ChaoMo, RengYang, ZhigangLi, YanlongHu, Qiangqiang
The life and safety of a battery are closely linked to temperature. Designing an effective thermal management system relies on a thorough understanding and analysis of the thermal properties and mechanisms of the battery. Over time, as batteries are used, their thermal characteristics change due to variations in internal SEI thickness, the deterioration of the active material structure, gas production, and electrolyte consumption, all of which are associated with the aging process. In this paper, experiments on both NCM and LFP batteries were made to measure the heat generation characteristics by adiabatic calorimeter. The results showed that the impact of calendar aging on battery heat generation exhibited completely different patterns for the lithium-ion batteries of the two material systems mentioned above. This paper provides guidance for the optimization of heat generation characteristics of battery and the calibration of heat source in the design of battery thermal management
Li, HaibinZhao, HongweiLiu, DinghongHu, Qiaosheng
This study leverages the temperature impact data obtained from the battery systems of airworthiness-certified fixed-wing electric aircraft to predict and correct the performance of eVTOL battery systems under various temperature conditions. Due to the lack of airworthiness-certified eVTOL models, it is challenging to directly test battery system parameters under temperature variations. However, using data from Ma Xin's team's production batteries tested on certified fixed-wing electric aircraft, we can accurately measure the effects of temperature changes. The capacity retention data at temperatures of -40°C, -20°C, -10°C, 0°C, 0°C, 25°C, 35°C, 45°C, 55°Care 78.14%, 83.3%, 84.1%, 88.1%, 92.3%, 100.0%, 102.0%, 103.9%, 104.6%. These quantified results provide a basis for modeling and experimental validation of eVTOL battery systems, ensuring their performance and safety across a wide range of temperatures. Although there are some research of battery system of eVtol in room temperature
Ma, XinDing, ShuitingPan, Yilun
SABERS, as this portfolio of innovations is named, refers to Solid-state Architecture Batteries for Enhanced Rechargeability and Safety. Developed jointly at NASA’s Glenn, Langley and Ames Research Centers, SABERS includes several advanced material, manufacturing and computational design innovations that enable a new paradigm in battery performance. The primary target application is next-generation electric aviation propulsion systems, yet SABERS will benefit other applications, too.
Batteries for eVTOL aircraft need to deliver high power for efficient takeoff and landing, as well as high energy for the cruise period. To meet these demands, designers must consider the power-energy tradeoff of batteries and integrate a reliable battery management system into the overall design. Multiphysics simulation can be used to evaluate this tradeoff and consider all design requirements in a way that is comprehensive and saves time. In recent years, more and more organizations have announced their development of electric vertical take-off and landing (eVTOL) systems and, in some cases, are even showing previews of systems that are intended to hit the market in just a few years. As new design ideas emerge, there is one important question that needs to be asked: To keep up with the developments in eVTOL aircraft, what design requirements need to be considered for the batteries that power them?
This article introduces an advanced state-of-charge (SOC) estimation method customized for 28 V LiFePO4 (LFP) helicopter batteries. The battery usage profile is characterized by four consecutive current pulses, each corresponding to distinct operational phases on the helicopter: instrument check, key-on, recharge, and emergency power output stages. To establish a precise battery model for LFP cells, the parameters of a second-order equivalent-circuit model are identified as a function of C-rate, SOC, and temperature. Furthermore, the observability of the battery model is assessed using extended Lie derivatives. The signal-to-noise ratio (SNR) of the open-circuit voltage (OCV)–SOC relation is analyzed and employed to evaluate the estimator’s resilience against OCV flatness. The extended Kalman filter (EKF) and the unscented Kalman filter (UKF) are utilized for SOC estimation. The results emphasize the significance of meticulously choosing process and sensor noise covariance matrices to
Gao, YizhaoNguyen, TrungOnori, Simona
Electric aircraft have emerged as a promising solution for sustainable aviation, aiming to reduce greenhouse gas emissions and noise pollution. Efficiently estimating and optimizing energy consumption in these aircraft is crucial for enhancing their design, operation, and overall performance. This paper presents a novel framework for analyzing and modeling energy consumption patterns in lightweight electric aircraft. A mathematical model is developed, encompassing key factors such as aircraft weight, velocity, wing area, air density, coefficient of drag, and battery efficiency. This model estimates the total energy consumption during steady-level flight, considering the power requirements for propulsion, electrical systems, and auxiliary loads. The model serves as the foundation for analyzing energy consumption patterns and optimizing the performance of lightweight electric aircraft. To facilitate analysis and visualization of energy consumption patterns, the study includes the
Kanchagar, Amogha
In the architecture of an Unmanned Aerial Vehicle (UAV), a crucial component responsible for the propulsion system is the electric motor. Over the years, different types of electric motors, including Brushless Direct Current (BLDC), have supported the UAV’s propulsion system in diverse configurations. However, in the context of flux flow, the Radial Flux Permanent Magnet Motor (RFPMM) has been given more priority than the Axial Flux Permanent Magnet Motor (AFPMM) due to its sustainability in design and construction. Nevertheless, the AFPMM boasts higher speed, power density, lower weight, and greater efficiency than the RFPMM, because of its shorter flux path and the absence of end-turn winding. Therefore, this paper focuses to conduct a suitability analysis of an AFPMM as a shaft-connected propeller-mounted motor, with the intention of replacing the RFPMM in UAV applications. The design of the AFPMM, incorporating topologies featuring a one-rotor, one-stator configuration, is
C, CarunaiselvaneKumar, Rajesh
The purpose of the Air Generation System is to provide a constant supply of conditioned fresh air to meet the necessary oxygen availability and to prevent CO2 concentrations for the occupants in an aircraft. The engine bleed energy or electrical load energy consumed towards this circumstance accounts to be approximately 5% of total fuel burn and in turn, contributes to the global emissions of greenhouse gases. This paper studies the improvement areas of the present conventional system such as fuel burn consumption associated with an aircraft ECS depending on the amount of bleed, ram air usage and electric power consumption. Improved systems for sustainability and hybridization in environmental control systems are desirable in aircraft. This paper explains how a new design of the sustainable hybrid module assists the conventional system, by using a proposed modular MPBR. The MPBR system generates oxygen-enriched air, which is mixed with the traditional fresh air generated from
Subrahmanya, ShreeshaKumar, NaveenRanjan, JayantKotnadh, Shivaprasad
Continuous improvements and innovations towards sustainability in the aviation industry has brought interest in electrified aviation. Electric aircrafts have short missions in which the temporal variability of thermal loads is high. Lithium-ion (Li-ion) batteries have emerged as prominent power source candidate for electric aircrafts and Urban Air Mobility (UAM). UAMs and Electric aircrafts have large battery packs with battery capacity ranging in hundreds or thousands of kWh. If the battery is exposed to temperatures outside the optimum range, the life and the performance of the battery reduces drastically. Hence, it is crucial to have a Thermal Management System (TMS) which would reduce the heat load on battery in addition to the cabin thermal loads. Thermal management can be done through active or passive cooling. Adding a passive cooling system like Phase Change Material (PCM) to the TMS reduces the design maximum thermal loads. However, the added weight of the PCM module may at
Nyamagoudar, VinayakP R, NamrathaBalasubrahmanyam, MadireddyVanka, SridharGattu, RaghavendraAbuheiba, AhmedJha, Rajesh Kumar
Lilium Munich, Germany +49 151-539-19945
The extent of automation and autonomy used in general aviation (GA) has been steadily increasing for decades, with the pace of development accelerating recently. This has huge potential benefits for safety given that it is estimated that 75% of the accidents in personal and on-demand GA are due to pilot error. However, an approach to certifying autonomous systems that relies on reversionary modes limits their potential to improve safety. Placing a human pilot in a situation where they are suddenly tasked with flying an airplane in a failed situation, often without sufficient situational awareness, is overly demanding. This consideration, coupled with advancing technology that may not align with a deterministic certification paradigm, creates an opportunity for new approaches to certifying autonomous and highly automated aircraft systems. The new paths must account for the multifaceted aviation approach to risk management which has interlocking requirements for airworthiness and
Dietrich, Anna MracekRajamani, Ravi
In commercial aerospace, the application areas for motors are wide and varied, each with their own unique requirements. From electric vehicle take-off and landing (eVTOL) air taxis to business jets to long-haul commercial transport aircraft, DC motors must endure various environmental conditions like extreme temperatures, shock and vibration, atmospheric pressures and signal interference, to name just a few. These applications may also demand motors that provide a fast response, high power or torque density. In addition to these requirements, the aerospace industry perpetually calls for lightweight materials and smaller installation spaces. Taken together, it can be very difficult to specify and buy a reliable motor for mission-critical equipment. This article will present common commercial aerospace applications that pose performance and environmental challenges for DC motors along with a summary of the stringent aerospace industry standards that the motors must satisfy. It will also
Airbus Toulouse, France +33 6 34 78 14 08
The aerospace industry is noticing significant shift towards More Electric Aircraft (MEA). The advancement of electrical technology the systems are being transformed towards electric compared to the conventional pneumatic or hydraulic systems. This has led to an increased demand in electrical power from 150 Kilo Watts in the conventional airplane to 1 Mega Watts in More Electric Aircraft. More electric systems, call for increased electrical wiring harness to connect various systems in the aircraft. These harnesses consist of power and data cables. Wireless communication technology is being matured for data communication, leading to reduction of wire harness for data. As of now, the length of wires in large commercial aircraft is over 100miles and it may not be surprising if the electrification of aircraft drive this too much longer. In this paper, a comparative study of various wireless power transfer techniques for DC voltage configuration and the corresponding challenges in an
C S, AdisheshaThirunarayana, Ashok KumarShreshthi, MahadevannaBarik, Mridul SankarBanerjee, Kumardeb
This SAE Aerospace Recommended Practice (ARP) is an industrial collaboration with regulatory bodies like the European Aviation Safety Agency (EASA) and the Federal Aviation Administration (FAA) to determine the worst-case credible thermal runaway (TR) condition (energy released and maximum temperature) for the design of an aviation large propulsion battery system to quantitatively verify TR in lieu of battery level RTCA DO-311A testing with protections disabled. The ARP considers the three stages of TR within a cell and defines the two critical temperatures for a specific cell design. These temperatures are key to understanding the layers of monitoring necessary to determine the severity of a TR event. Different trigger methods can be used to quantify the heating characteristics and resultant energy profile releases as a function of time. Results show three general phases of the event critical temperature (see 1.5) corresponding with the reaction between the cell’s solid electrolyte
AE-7D Aircraft Energy Storage and Charging Committee
Airbus Toulouse, France +33 6 34 78 14 08
Electric vertical take-off and landing aircraft (eVTOL) has become a main trend in general aviation. Battery, power electronic and motor have made big progress in the last decades, most companies and research institutions are focusing on the development of 2-5 seat (2 tons maximum takeoff weight) eVTOL products and strat to put into market. This paper tried to defines the design and analysis process of electric propulsion system taking 2-ton eVTOL as an example. Firstly, the parameters of the aircraft is defined and the power and energy consumption was analyzed based on flight phase. Secondly, the electric propulsion system architecture is defined based on the aircraft design. The design and evaluation of propeller, motor, motor controller and battery were carried out respectively. The optimal design of propeller in hover stage and cruise stage is conducted. Based on the existing products, the selection of the motor and motor controller are conducted, and the matching design with the
Li, HongliangWang, LijianKang, Yuanli
Advanced flight control system, aviation battery and motor technologies are driving the rapid development of eVTOL to offer possibilities for Urban Air Mobility. The safety and airworthiness of eVTOL aircraft and systems are the critical issues to be considered in eVTOL design process. Regarding to the flight control system, its complexity of design and interfaces with other airborne systems require detailed safety assessment through the development process. Based on SAE ARP4754A, a forward architecture design process with comprehensive safety assessment is introduced to achieve complete safety and hazard analysis. The new features of flight control system for eVTOL are described to start function capture and architecture design. Model-based system engineering method is applied to establish the functional architecture in a traceable way. SFHA and STPA methods are applied in a complementary way to identify the potential safety risk caused by failure and unsafe control action. PSSA with
Ning, ChengweiZhang, HaoWeng, HaiminMa, Ran
Electric technology has gradually changed the form of energy use in transportation. Electric vertical take-off and landing aircraft (eVTOL) will become an important means of transportation in the future, bringing significant changes to urban transportation and providing a more convenient and comfortable travel experience for people. eVTOLs are being extensively researched and developed by the global aviation industry as well as by many innovative technology companies. In this paper, we focus on the system design and testing of the four-axis and eight-propeller eVTOL. The overall parameters of the aircraft are defined, and the energy and power architecture design and analysis are carried out. Carry out the hybrid power supply design of lithium battery and fuel cell, and complete the parameter matching design of power system. The lithium battery and fuel cell hybrid power supply, single propeller test, dual propeller test, system integration verification were carried out, and finally the
Li, HongliangLuo, ZhongpeiDong, WeiWang, Fujing
Electric vertical takeoff and landing (eVTOL) aircraft, which is used extensively in both military and civilian fields, has the advantages of good maneuverability, high cruising speed, and low requirements for the takeoff and landing modes. Robust and stable control is crucial to ensuring its safety because the dynamics model of an eVTOL aircraft will change significantly between fixed-wing and vertical takeoff and landing mode. In this paper, we first study the structural characteristics of the eVTOL aircraft and establish its dynamic model by considering typical flight modes and mechanical parameters. Then we design a closed-loop controller based on cascade PID technique. Finally, the effectiveness of the control algorithms is verified based on the semi-physical flight simulation platform, which can lower the development cost of control algorithms significantly. The simulation results demonstrate that the cascade PID control scheme accelerates the implementation of the robust
Shi, JiekaiLi, WeiWang, FangBai, Jie
Electrical Vertical Takeoff and Landing (eVTOL) vehicles hold great promises for revolutionizing urban mobility. Their emergences as a transformative transportation technology has led multiple Original Equipment Manufacturers (OEM) competing for market share, with important variety of technical solutions, all necessitating to demonstrate the compliance to safety requirements and regulations. Model Based Safety Analysis (MBSA), newly introduced in ARP4761A and based on compositional and modular representation of failure propagation paths within one system, provides a unique opportunity to increase efficiency by maximizing the possible reuse of safety analyses elements across multiple architectures (“product line” philosophy). Generic library of safety models for elements of variant architectures can be efficiently constructed using MBSA techniques that can then support safety analyses on variant architectures or architectures trade-off. This approach can facilitate a safety process that
Adeline, RomainWang, JiaHua, Angelina
With increasing interest in the urban air traffic market for electric Vertical Take-Off and Landing (eVTOL) vehicles, there are opportunities to enhance flight performance through new technologies and control methods. One such concept is the propulsion wing, which incorporates a cross-flow fan (CFF) at the wing's trailing edge to drive the vehicle's flight. This article presents a wind tunnel experiment aimed at analyzing the aerodynamic characteristics of the propulsive wing for the novel eVTOL vehicle. The experiment encompasses variations in angels of attack, free stream velocities and fan rotational speeds. The result verifies that cross-flow fans offer unique flow control capabilities, achieving a tested maximum lift coefficient exceeding 7.6. Since flow from the suction surface is ingested into the CFF, the flow separation at large angle of attack (up to 40°) is effectively eliminated. The aerodynamic performance of the propulsive wing depends on the advance ratio and angle of
Wang, JunjieZhang, XinfengHan, Yue
Joby Aviation Santa Cruz, CA 831-201-6700
A team of MIT engineers is creating a one-megawatt motor that could be a key stepping-stone toward electrifying larger aircraft. The team has designed and tested the major components of the motor and has shown through detailed computations that the coupled components can work as a whole to generate one megawatt of power — at a weight and size competitive with current small aero-engines.
The advanced air mobility sector — which includes electric-powered urban and regional aircraft — may become a $1.5 trillion market by 2040. New startup Aerovy Mobility could benefit airport and vertiport operators and real estate developers looking to establish advanced air mobility technology at existing and potential sites.
Advancements in electric vertical takeoff and landing (eVTOL) aircraft have generated significant interest within and beyond the traditional aviation industry. One particularly promising application involves on-demand, rapid-response use cases to broaden first responders, police, and medical transport mission capabilities. With the dynamic and varying public service operations, eVTOL aircraft can offer potentially cost-effective aerial mobility components to the overall solution, including significant lifesaving benefits. The Use of eVTOL Aircraft for First Responder, Police, and Medical Transport Applications discusses the challenges need to be addressed before identified capabilities and benefits can be realized at scale: Mission-specific eVTOL vehicle development Operator- and patient-specific accommodations Detect-and-avoid capabilities in complex and challenging operating environments Autonomous and artificial intelligence-enhanced mission capabilities Home-base charging systems
Doo, Johnny
Hybrid electric aircraft propulsion is an emerging technology that presents a variety of potential benefits along with technical integration challenges. Developing these new propulsion architectures with their complex control systems, and ultimately proving their benefit, is a multistep process. This process includes concept development and analysis, dynamic simulation, hardware-in-the-loop testing, full-scale testing, and so on. This effort is being revolutionized and indeed enabled by new digital tools that support increasing the technology readiness level throughout the maturation process. As part of this Digital Transformation, NASA has developed a suite of publicly available digital tools that facilitate the path from concept to implementation. This paper describes the NASA-developed tools and puts them in the context of control system development for hybrid electric aircraft propulsion. The three MATLAB®-based software packages are the Toolbox for the Modeling and Analysis of
Litt, Jonathan S.
For the past three decades, lithium-ion (Li-ion) batteries have reigned supreme – proving their performance in smartphones, laptops, and electric vehicles. But battery researchers have begun to approach the limits of Li-ion. As next-generation long-range vehicles and electric aircraft start to arrive on the market, the search for safer, cheaper, and more powerful battery systems that can outperform Li-ion is ramping up.
In the last decades, the requirement related to the reduction of energy waste has been focused on the aeronautical field for decreasing CO2 emissions in propulsion systems, coupled with the possibility of improving their ecological sustainability. Performance of hybrid electric aircraft are affected by the sizes and weights of propulsion systems typically constituted of internal combustion engines and electric motors. Therefore, the correct design of propulsive architectures is fundamental to ensure a desired state of charge target level of batteries compliant with the flight plan provided by a driver unit. A Linear Time Variant Model Predictive Control (LTV-MPC) strategy for energy management purposes of an aeronautical hybrid powertrain is proposed in the present work. The MPC, designed as a supervisor, provides the best trade-off between command torques of motors belonging to a parallel-hybrid propulsion system to guarantee the final state of charge as close as possible to the
Fornaro, EnricoTordela, Ciro
Electrification is seen as having an important role to play in the fossil-free aviation of tomorrow. But the more energy-efficient an electric aircraft is, the noisier its propellers get. Now, researchers at Chalmers University of Technology have developed a propeller design optimization method that paves the way for quiet, efficient electric aviation.
Electric aviation mirrors the early stages of the electric vehicle revolution After decades of tantalizing breakthroughs in battery technology, the last decade witnessed the emergence of energy storage as a challenger to fossil fuels for powering vehicles. We are now in the midst of a once-in-a-lifetime opportunity to change the energy landscape and electrify all forms of transportation: light duty passenger cars, heavy duty commercial vehicles, as well as various forms of transportation such as trains, ships, and aircraft. Such a dramatic transition will require a multifaceted approach that takes into consideration technology needs, infrastructure support, workforce transitions, safety and regulations, and energy justice. The U.S. Department of Energy's (DOE) Argonne National Laboratory, with numerous public and private sector collaborators, has been strategizing about this transition to ensure the lessons from the past are applied to the future.
Drop-in replacement biofuels and electrofuels can provide net-zero CO2 emissions with dramatic reductions in contrail formation. Biofuels must transition to second-generation cellulosic feedstocks while improving land and soil management. Electrofuels, or "e-fuels,” require aggressive cost reduction in hydrogen production, carbon capture, and fuel synthesis. Hydrogen has great potential for energy efficiency, cost reduction, and emissions reduction; however, its low density (even in liquid form) combined with it’s extremely low boiling temperature mean that bulky spherical tanks will consume considerable fuselage volume. Still, emerging direct-kerosene fuel cells may ultimately provide a superior zero-emission, energy-dense solution. Decarbonized Power Options for Civil Aviation discusses the current challenges with these power options and explores the economic incentives and levers vital to decarbonization. Until common and enforceable global carbon pricing arrives, targeted national
Muelaner, Jody E.
This Aerospace Information Report (AIR) provides information on systems integration rigs, commonly referred to as “Iron Birds” for aerospace applications. a It includes background historical information including descriptions of Iron Birds produced to date, important component elements and selection rationale, hydraulic system design and operational modes and illustrates the design approaches to be considered. b It provides illustrations of the various systems that should be considered for Iron Bird testing in the development phase and utilization during the production program. c It includes recommendations for simulation, component development tests, system integration and lessons learned.
A-6A3 Flight Control and Vehicle Management Systems Cmt
The objective of this document is to define basic terms and definitions and to provide general guidance for M&S of aircraft EPS.
AE-7M Aerospace Model Based Engineering
This SAE Aerospace Standard (AS) establishes the characteristics and utilization of 270 V DC electric power at the utilization equipment interface and the constraints of the utilization equipment based on practical experience. These characteristics shall be applicable for both airborne and ground support power systems. This document also defines the related distribution and installation considerations. Utilization equipment designed for a specific application may not deviate from these requirements without the approval of the procuring activity.
AE-7C Systems
Today our aviation capability is built upon a carefully iterative evolution in technology over more than a century, in this time craft have become highly optimized machines with every incremental technological advance pushing the envelope of capability and economy. However it is widely accepted that our current progression towards electric aircraft requires significant innovation across most, if not all, aircraft subsystems. This is a gap that no single iterative evolution can bridge. A revolution is required. Rim-driven fan (RDF) technology is not innately new as this technology has become successful in the marine industry in the last decade, however it has never been able to pass feasibility in aerospace applications. The approach did not merit serious investigation until aircraft electrification became a solid target for the industry, and with heritage architecture minimizing the certification risk for first movers it has been an under-developed area of research since.
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