scholarly journals A Collaborative Approach for an Integrated Modeling of Urban Air Transportation Systems

Aerospace ◽  
2020 ◽  
Vol 7 (5) ◽  
pp. 50
Author(s):  
Malte Niklaß ◽  
Niclas Dzikus ◽  
Majed Swaid ◽  
Jan Berling ◽  
Benjamin Lührs ◽  
...  
Keyword(s):  
Data Exchange ◽  
Electrical Energy ◽  
Transportation Systems ◽  
System Level ◽  
Urban Air ◽  
Physical Analysis ◽  
Demand Forecast ◽  
System Module ◽  
Physical Effects ◽  
Storage Technologies

The current push in automation, communication, and electrical energy storage technologies has the potential to lift urban mobility into the sky. As several urban air mobility (UAM) concepts are conceivable, all relevant physical effects as well as mutual interrelations of the UAM system have to be addressed and evaluated at a sufficient level of fidelity before implementation. Therefore, a collaborative system of systems modeling approach for UAM is presented. To quickly identify physical effects and cross-disciplinary influences of UAM, a pool of low-fidelity physical analysis components is developed and integrated into the Remote Component Environment (RCE) workflow engine. This includes, i. a., the disciplines of demand forecast, trajectory, vertiport, and cost modeling as well as air traffic flow and capacity management. The definition and clarification of technical interfaces require intensive cooperation between specialists with different areas of expertise. To reduce this communication effort, the Common Parametric Aircraft Configuration Schema (CPACS) is adapted and used as central data exchange format. The UAM system module is initially applied for a 24-hour simulation of three generic networks in Hamburg City. After understanding the basic system-level behavior, higher level analysis components and feedback loops must be integrated in the UAM system module for evaluation and optimization of explicit operating concepts.

scholarly journals Improved Thermal Transfer Efficiency for Planar Solar Thermophotovoltaic Devices

2013 ◽  
Author(s):  
David M. Bierman ◽  
Andrej Lenert ◽  
Evelyn N. Wang
Keyword(s):  
Solar Energy ◽  
Solar Spectrum ◽  
Electrical Energy ◽  
Photovoltaic Cell ◽  
Area Ratio ◽  
Transfer Efficiency ◽  
System Level ◽  
Surface Geometry ◽  
Thermal Transfer ◽  
Absorber Surface

Solar thermophotovoltaic (STPV) devices provide conversion of solar energy to electrical energy through the use of an intermediate absorber/emitter module, which converts the broad solar spectrum to a tailored spectrum that is emitted towards a photovoltaic cell [1]. While the use of an absorber/emitter device could potentially overcome the Shockley-Queisser limit of photovoltaic conversion [2], it also increases the number of heat loss mechanisms. One of the most prohibitive aspects of STPV conversion is the thermal transfer efficiency, which is a measure of how well solar energy is delivered to the emitter. Although reported thermophotovoltaic efficiencies (thermal to electric) have exceeded 10% [3], [4], previously measured STPV conversion efficiencies are below 1% [5], [6], [7]. In this work, we present the design and characterization of a nanostructured absorber for use in a planar STPV device with a high emitter-to-absorber area ratio. We used a process for spatially-selective growth of vertically aligned multi-walled carbon nanotube (MWCNT) forests on highly reflective, smooth tungsten (W) surfaces. We implemented these MWCNT/W absorbers in a TPV system with a one-dimensional photonic crystal emitter, which was spectrally paired with a low bandgap PV cell. A high fidelity, system-level model of the radiative transfer in the device was experimentally validated and used to optimize the absorber surface geometry. For an operating temperature of approximately 1200 K, we experimentally demonstrated a 100% increase in overall STPV efficiency using a 4 to 1 emitter-to-absorber area ratio (relative to a 1 to 1 area ratio), due to improved thermal transfer efficiency. By further increasing the solar concentration incident on the absorber surface, increased emitter-to-absorber area ratios will improve both thermal transfer and overall efficiencies for these planar devices.

scholarly journals A Transportation Performance Measurement System with a Mississippi Case Study

2010 ◽  
Author(s):  
Haiyuan Wang ◽  
Mingzhou Jin
Keyword(s):  
Performance Measures ◽  
Transportation Systems ◽  
System Level ◽  
Performance Measurement System ◽  
Intermodal Transportation ◽  
Design Alternatives ◽  
Level Performance ◽  
Existing Data ◽  
Highway System

In current literature and practices, there are no systematic and user-oriented intermodal transportation performance measures. After identifying customer needs and transportation goals, this paper proposes a set of system-level performance measures for intermodal transportation that are user-oriented, scalable, systematic, and scientific. The measures can be used to compare intermodal design alternatives or to evaluate existing transportation systems with any size and any mode. The highway system in Mississippi is analyzed as a case study. The case study demonstrates the existing data sources, the methods of calculating the measures, and the means of evaluating transportation systems with the measures.

scholarly journals Renewable electricity storage using electrolysis

2019 ◽  
Vol 117 (23) ◽  
pp. 12558-12563 ◽  
Author(s):  
Zhifei Yan ◽  
Jeremy L. Hitt ◽  
John A. Turner ◽  
Thomas E. Mallouk
Keyword(s):  
Energy Storage ◽  
Water Electrolysis ◽  
Electrical Energy ◽  
Chemical Energy ◽  
Liquid Fuels ◽  
System Level ◽  
Renewable Electricity ◽  
Short Term ◽  
Stable Chemical ◽  
Renewable Energy Storage

Electrolysis converts electrical energy into chemical energy by storing electrons in the form of stable chemical bonds. The chemical energy can be used as a fuel or converted back to electricity when needed. Water electrolysis to hydrogen and oxygen is a well-established technology, whereas fundamental advances in CO2electrolysis are still needed to enable short-term and seasonal energy storage in the form of liquid fuels. This paper discusses the electrolytic reactions that can potentially enable renewable energy storage, including water, CO2and N2electrolysis. Recent progress and major obstacles associated with electrocatalysis and mass transfer management at a system level are reviewed. We conclude that knowledge and strategies are transferable between these different electrochemical technologies, although there are also unique complications that arise from the specifics of the reactions involved.

scholarly journals Blockchain for the Internet of Vehicles: A Decentralized IoT Solution for Vehicles Communication Using Ethereum

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3928 ◽  
Author(s):  
Rateb Jabbar ◽  
Mohamed Kharbeche ◽  
Khalifa Al-Khalifa ◽  
Moez Krichen ◽  
Kamel Barkaoui
Keyword(s):  
Intelligent Transportation Systems ◽  
Secure Communication ◽  
Data Exchange ◽  
Smart Cities ◽  
Transportation Systems ◽  
Smart Devices ◽  
The Internet ◽  
Internet Of Vehicles ◽  
Computing Platform ◽  
Blockchain Technology

The concept of smart cities has become prominent in modern metropolises due to the emergence of embedded and connected smart devices, systems, and technologies. They have enabled the connection of every “thing” to the Internet. Therefore, in the upcoming era of the Internet of Things, the Internet of Vehicles (IoV) will play a crucial role in newly developed smart cities. The IoV has the potential to solve various traffic and road safety problems effectively in order to prevent fatal crashes. However, a particular challenge in the IoV, especially in Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communications, is to ensure fast, secure transmission and accurate recording of the data. In order to overcome these challenges, this work is adapting Blockchain technology for real time application (RTA) to solve Vehicle-to-Everything (V2X) communications problems. Therefore, the main novelty of this paper is to develop a Blockchain-based IoT system in order to establish secure communication and create an entirely decentralized cloud computing platform. Moreover, the authors qualitatively tested the performance and resilience of the proposed system against common security attacks. Computational tests showed that the proposed solution solved the main challenges of Vehicle-to-X (V2X) communications such as security, centralization, and lack of privacy. In addition, it guaranteed an easy data exchange between different actors of intelligent transportation systems.

Reconfigurable distributed real-time processing for multi-robot control: Design, implementation and experimentation

Robotica ◽  
2004 ◽  
Vol 22 (6) ◽  
pp. 661-679 ◽  
Author(s):  
J. Z. Pan ◽  
R. V. Patel
Keyword(s):  
Real Time ◽  
Information Exchange ◽  
Robot Control ◽  
Data Exchange ◽  
Processing System ◽  
System Level ◽  
Layered System ◽  
Test Bed ◽  
Design And Implementation ◽  
Multi Robot

Sophisticated robotic applications require systems to be reconfigurable at the system level. Aiming at this requirement, this paper presents the design and implementation of a software architecture for a reconfigurable real-time multi-processing system for multi-robot control. The system is partitioned into loosely coupled function units and the data modules manipulated by the function units. Modularized and unified structures of the sub-controllers and controller processes are designed and constructed. All the controller processes run autonomously and intra-sub-controller information exchange is realized by shared data modules that serve as a data repository in the sub-controller. The dynamic data-management processes are responsible for data exchange among sub-controllers and across the computer network. Among sub-controllers there is no explicit temporal synchronization and the data dependencies are maintained by using datum-based synchronization. The hardware driver is constructed as a two-layered system to facilitate adaptation to various robotic hardware systems. A series of effective schemes for software fault detection, fault anticipation and fault termination are accomplished to improve run-time safety. The system is implemented cost-effectively on a QNX real-time operating system (RTOS) based system with a complete PC architecture, and experimentally validated successfully on an experimental dual-arm test-bed. The results indicate that the architectural design and implementation are well suited for advanced application tasks.

Electrical Energy Storage in Transportation Systems

2016 ◽  
Author(s):  
Benoît Robyns ◽  
Christophe Saudemont ◽  
Daniel Hissel ◽  
Xavier Roboam ◽  
Bruno Sareni ◽  
...  
Keyword(s):  
Energy Storage ◽  
Electrical Energy ◽  
Transportation Systems ◽  
Electrical Energy Storage

scholarly journals LEARNING INDIRECT ACTIONS IN COMPLEX DOMAINS: ACTION SUGGESTIONS FOR AIR TRAFFIC CONTROL

2009 ◽  
Vol 12 (04n05) ◽  
pp. 493-512 ◽  
Author(s):  
ADRIAN AGOGINO ◽  
KAGAN TUMER
Keyword(s):  
New York ◽  
Traffic Control ◽  
Transportation Systems ◽  
Air Traffic ◽  
Automated System ◽  
System Level ◽  
Research Issues ◽  
Air Traffic Controllers ◽  
Out Of The Loop ◽  
Series Of Experiments

Providing intelligent algorithms to manage the ever-increasing flow of air traffic is critical to the efficiency and economic viability of air transportation systems. Yet, current automated solutions leave existing human controllers "out of the loop" rendering the potential solutions both technically dangerous (e.g. inability to react to suddenly developing conditions) and politically charged (e.g. role of air traffic controllers in a fully automated system). Instead, this paper outlines a distributed agent-based solution where agents provide suggestions to human controllers. Though conceptually pleasing, this approach introduces two critical research issues. First, the agent actions are now filtered through interactions with other agents, human controllers and the environment before leading to a system state. This indirect action-to-effect process creates a complex learning problem. Second, even in the best case, not all air traffic controllers will be willing or able to follow the agents' suggestions. This partial participation effect will require the system to be robust to the number of controllers that follow the agent suggestions. In this paper, we present an agent reward structure that allows agents to learn good actions in this indirect environment, and explore the ability of those suggestion agents to achieve good system level performance. We present a series of experiments based on real historical air traffic data combined with simulation of air traffic flow around the New York city area. Results show that the agents can improve system-wide performance by up to 20% over that of human controllers alone, and that these results degrade gracefully when the number of human controllers that follow the agents' suggestions declines.

Operating Conditions and System Considerations for a Reversible Solid Oxide Cell System for Electrical Energy Storage

2014 ◽  
Author(s):  
Christopher H. Wendel ◽  
Pejman Kazempoor ◽  
Robert J. Braun
Keyword(s):  
Energy Storage ◽  
Thermal Management ◽  
Management Strategies ◽  
Electrical Energy ◽  
Cell System ◽  
Operating Conditions ◽  
Solid Oxide ◽  
System Level ◽  
Widespread Application ◽  
Electrical Energy Storage

Electrical energy storage (EES) is an important component of the future electric grid. Given that no other widely available technology meets all the EES requirements, reversible (or regenerative) solid oxide cells (ReSOCs) working in both fuel cell (power producing) and electrolysis (fuel producing) modes are envisioned as a technology capable of providing highly efficient and cost-effective EES. However, there are still many challenges from cell materials development to system level operation of ReSOCs that should be addressed before widespread application. One particular challenge of this novel system is establishing effective thermal management strategies to maintain the high conversion efficiency of the ReSOC. The system presented in this paper employs a thermal management strategy of promoting exothermic methanation in the ReSOC stack to offset the endothermic electrolysis reactions during charging mode (fuel producing) while also enhancing the energy density of the stored gases. Modeling and parametric analysis of an energy storage concept is performed using a thermodynamic system model coupled with a physically based ReSOC stack model. Results indicate that roundtrip efficiencies greater than 70% can be achieved at intermediate stack temperature (∼680°C) and pressure (∼20 bar). The optimal operating conditions result from a tradeoff between high stack efficiency and high parasitic balance of plant power.

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