The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform

Uwe Wollrab - One of the best experts on this subject based on the ideXlab platform.

  • performance assessment of turbocharged pem fuel cell systems for civil aircraft onboard power production
    Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2008
    Co-Authors: Stefano Campanari, Andrea Beretti, Giampaolo Manzolini, Uwe Wollrab
    Abstract:

    Stefano Campanari Associate Professor e-mail: stefano.campanari@polimi.it Giampaolo Manzolini Research Engineer e-mail: giampaolo.manzolini@polimi.it Andrea Beretti Research Engineer Dipartimento di Energetica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy Uwe Wollrab Systems Engineering, Fuel Cell Systems Development, AIRBUS Deutschland Gmbh, 21129Hamburg, Germany e-mail: uwe.wollrab@airbus.com Performance Assessment of Turbocharged Pem Fuel Cell Systems for Civil Aircraft Onboard Power Production In recent years, civil aircraft projects are showing a continuous increase in the demand of onboard electrical power, both for the partial substitution of hydraulic or pneumatic controls and drives with electrical ones, and for the consumption of new auxiliary sys- tems developed in response to Flight safety and environmental control issues. Aiming to generate onboard power with low emissions and better efficiency, several manufacturers and research groups are considering the possibility to produce a relevant fraction of the electrical power required by the aircraft by a fuel cell system. The first step would be to replace the conventional auxiliary power unit (based on a small gas turbine) with a polymer electrolyte membrane (PEM) fuel cell type, which today is favored with respect to other fuel cell types; thanks to its higher power density and faster startup. The PEM fuel cell can be fed with a hydrogen rich gas coming from a fuel reformer, operating with the same jet fuel used by the aircraft, or relying on a dedicated hydrogen storage on- board. The cell requires also an air compression unit, where the temperature, pressure, and humidity of the air stream feeding the PEM unit during land and in-Flight Operation strongly influence the performance and the physical integrity of the fuel cell. In this work we consider different system architectures, where the air compression system may exploit an electrically driven compressor or a turbocharger unit. The compressor type and the system pressure level are optimized according to a fuel cell simulation model, which calculates the cell voltage and efficiency as a function of temperature and pressure, calibrated over the performances of real PEM cell components. The system performances are discussed under different operating conditions, covering ground Operation, and in- termediate and high altitude cruise conditions. The optimized configuration is selected, presenting energy balances and a complete thermodynamic analysis. 关DOI: 10.1115/1.2772636兴 Introduction New projects of civil aircrafts are in these years frequently influenced by a development strategy focusing on more electric aircraft 共MEA兲 or even all electric aircraft 共AEA兲 concepts. The partial substitution of conventional hydraulic or pneumatic con- trols and drives with electrical ones 共see Table 1兲, and the intro- duction of new auxiliary systems bring about an increase in on- board electric power consumption, reaching values around 560 kW for airplanes such as the B777 or A330/A340, and going toward 1.3– 1.5 MW for next generation aircrafts 关1–5兴. Furthermore, the possible elimination of power offtakes from the main engines would increase the nominal power output re- quired by a separated onboard electricity generator. It is well known that a fraction of electric power is generated on-board civil aircrafts by small turbine units, acting as auxiliary power units 共APUs兲. Such machines operate with simple cycle, uncooled Operation, low turbine inlet temperature 共TIT兲, and pres- sure ratio, generally with single stage radial compressor and a power output in the range of several tenth kilowatts and up to the hundred kilowatt scale. Their advantages include low weight, rapid startup, and robustness; disadvantages are primarily the low efficiency 共15–18%兲 and significant NO x and CO emissions. The Contributed by the International Gas Turbine Institute of ASME for publication in the J OURNAL OF E NGINEERING FOR G AS T URBINES AND P OWER . Manuscript received April 28, 2007; final manuscript received May 9, 2007; published online February 29, 2008. Review conducted by Dilip R. Ballal. Paper presented at the ASME Turbo Expo 2007: Land, Sea and Air 共GT2007兲, Montreal, Quebec, Canada, May 14–17, 2007, Paper No. GT2007-27658. possible removal of power offtakes from the main engines would increase the nominal power of the APU system, making more important to look for higher efficiency and lower pollution de- vices. Polymer electrolyte membrane fuel cells 共PEM FCs兲 on their own are widely experimented in prototypes and generally recog- nized very attractive for future application in the automotive field; thanks to their ability to generate electricity with high efficiency 共e.g., 50–55%兲 in tenth-kilowatt scale systems fed with hydrogen and operating at low temperatures 共60– 70° C兲. They also show a rather high power density 共in terms of kW/kg and kW/ dm 3 兲, fast startup, and negligible emissions. The quick development of this technology has suggested to consider their application also in the aeronautic field, within the perspective of a step by step develop- ment, which could also represent a new possible market for the beginning of their commercialization. The technology roadmap for this development includes several steps, where the first should be introducing a pure hydrogen PEM system with minor aircraft changes, aiming to provide a fraction of electric power 共well below the potential power requirements shown in Table 1兲 for auxiliary loads and emergency systems actually sustained by APUs and other generators 共for instance, the air turbine that is used to drive the pumps of the emergency hy- draulic circuit兲. Subsequent steps could involve the use of onboard reformers 关3兴 as well as different FC types with increasing power output. The concept of integrating a PEM unit onboard civil aircrafts has been already introduced in several works 关2,6,7兴, where the fuel cell has been generally considered as a device with assigned Journal of Engineering for Gas Turbines and Power Copyright © 2008 by ASME MARCH 2008, Vol. 130 / 021701-1 Downloaded From: http://gasturbinespower.asmedigitalcollection.asme.org/ on 02/17/2016 Terms of Use: http://www.asme.org/about-asme/terms-of-use

  • Performance assessment of turbocharged PEM fuel cell systems for civil aircraft onboard power production
    Volume 3: Turbo Expo 2007, 2007
    Co-Authors: Stefano Campanari, Andrea Beretti, Giampaolo Manzolini, Uwe Wollrab
    Abstract:

    In recent years, civil aircraft projects are showing a continuous increase in the demand of onboard electrical power, both for the partial substitution of hydraulic or pneumatic controls and drives with electrical ones, and for the consumption of new auxiliary systems developed in response to Flight safety and environmental control issues. Aiming to generate on-board power with low emissions and better efficiency, several manufacturers and research groups are considering the possibility to produce a relevant fraction of the electrical power required by the aircraft by a fuel cell system. The first step would be to replace the conventional auxiliary power unit (APU, based on a small gas turbine) with a Polymer Membrane fuel cell type (PEM), which today is favored with respect to other fuel cell types thanks to its higher power density and faster start-up. The PEM fuel cell can be fed with an hydrogen rich gas coming from a fuel reformer, operating with the same jet fuel used by the aircraft, or relying on a dedicated hydrogen storage onboard. The cell requires also an air compression unit, where the temperature, pressure and humidity of the air stream feeding the PEM unit during land and in-Flight Operation strongly influence the performance and the physical integrity of the fuel cell. In this work we consider different system architectures, where the air compression system may exploit an electrically driven compressor or a turbocharger unit. The compressor type and the system pressure level are optimized according to a fuel cell simulation model which calculates the cell voltage and efficiency as a function of temperature and pressure, calibrated over the performances of real PEM cell components. The system performances are discussed under different operating conditions, covering ground Operation, intermediate and high altitude cruise conditions. The optimized configuration is selected, presenting energy balances and a complete thermodynamic analysis.Copyright © 2007 by ASME

Fulvia Quagliotti - One of the best experts on this subject based on the ideXlab platform.

  • The Design of GDPR-Abiding Drones Through Flight Operation Maps: A Win–Win Approach to Data Protection, Aerospace Engineering, and Risk Management
    Minds and Machines, 2019
    Co-Authors: Eleonora Bassi, Nicoletta Bloise, Jacopo Dirutigliano, Gian Piero Fici, Stefano Primatesta, Ugo Pagallo, Fulvia Quagliotti
    Abstract:

    Risk management is a well-known method to face technological challenges through a win–win combination of protective and proactive approaches, fostering the collaboration of operators, researchers, regulators, and industries for the exploitation of new markets. In the field of autonomous and unmanned aerial systems, or UAS, a considerable amount of work has been devoted to risk analysis, the generation of ground risk maps, and ground risk assessment by estimating the fatality rate. The paper aims to expand this approach with a tool for managing data protection risks raised by drones through the design of Flight maps. The tool should allow UAS operators choosing the best air corridor for their drones based on the so-called privacy by design principle pursuant to Article 25 of the EU data protection regulation, the GDPR. Among the manifold applications of this approach, the design of fly zones for drones can be tailored for public authorities in the phase of authorization of new Operations, much as for national Data Protection authorities that have to control the lawfulness of personal data processing by UAS Operations. The overall aim is to present the first win–win approach to data protection issues, aerospace engineering challenges, and risk management methods for the threats posed by this technology.

  • the design of gdpr abiding drones through Flight Operation maps a win win approach to data protection aerospace engineering and risk management
    Minds and Machines, 2019
    Co-Authors: Eleonora Bassi, Nicoletta Bloise, Jacopo Dirutigliano, Gian Piero Fici, Stefano Primatesta, Ugo Pagallo, Fulvia Quagliotti
    Abstract:

    Risk management is a well-known method to face technological challenges through a win–win combination of protective and proactive approaches, fostering the collaboration of operators, researchers, regulators, and industries for the exploitation of new markets. In the field of autonomous and unmanned aerial systems, or UAS, a considerable amount of work has been devoted to risk analysis, the generation of ground risk maps, and ground risk assessment by estimating the fatality rate. The paper aims to expand this approach with a tool for managing data protection risks raised by drones through the design of Flight maps. The tool should allow UAS operators choosing the best air corridor for their drones based on the so-called privacy by design principle pursuant to Article 25 of the EU data protection regulation, the GDPR. Among the manifold applications of this approach, the design of fly zones for drones can be tailored for public authorities in the phase of authorization of new Operations, much as for national Data Protection authorities that have to control the lawfulness of personal data processing by UAS Operations. The overall aim is to present the first win–win approach to data protection issues, aerospace engineering challenges, and risk management methods for the threats posed by this technology.

Sumit Kumar - One of the best experts on this subject based on the ideXlab platform.

  • solar x ray spectrometer soxs mission on board gsat2 indian spacecraft the low energy payload
    Solar Physics, 2005
    Co-Authors: Rajmal Jain, Hemant Dave, Amit Shah, N M Vadher, Vishal Shah, Girish Ubale, K S B Manian, Chirag Solanki, K J Shah, Sumit Kumar
    Abstract:

    The first space-borne solar astronomy experiment of India, namely “Solar X-ray Spectrometer (SOXS)”, was successfully launched on 08 May 2003 on board geostationary satellite GSAT-2 of India. The SOXS is composed of two independent payloads, viz. SOXS Low-Energy Detector (SLD) Payload and SOXS High-Energy Detector (SHD) Payload. The SOXS aims to study the full-disk integrated X-ray emission in the energy range from 4 keV to 10 MeV. In this paper we present the first report on the SLD instrumentation and its in-orbit performance. The SLD payload was designed and developed at the Physical Research Laboratory in collaboration with various centers of Indian Space Research Organisation (ISRO). The basic scientific aim of the SLD payload is to study solar flares in the energy range from 4 to 60 keV with high spectral and temporal resolution. To meet these requirements, the SLD payload employs state-of-the-art solid state detectors, the first time for a solar astronomy experiment, viz. Si PIN (4 –25 keV), and cadmium–zinc–telluride (4 –60 keV). With their superb high-energy resolution characteristics, SLD can observe iron and iron–nickel complex lines that are visible only during solar flares. In view of its 3.4∘ FOV, the detector package is mounted on a Sun Aspect System, for the first time, to get uninterrupted observations in a geostationary orbit. The SLD payload configuration, its in-Flight Operation, and the response of the detectors are presented. We also present the first observations of solar flares made by the SLD payload and briefly describe their temporal and spectral mode results.

M N Nozdrachev - One of the best experts on this subject based on the ideXlab platform.

  • results of in Flight Operation of scientific payload on micro satellite kolibri 2000
    Acta Astronautica, 2005
    Co-Authors: S I Klimov, Yuri V Afanasyev, N A Eismont, Egor A Grachev, O R Grigoryan, V A Grushin, Dmitri S Lysakov, M N Nozdrachev
    Abstract:

    Abstract The realization of Russian–Australian scientific—educational micro-satellite “Kolibri-2000” (weight of 20.5 kg, http://www.kolibri2000.ru 20 March, 2002), delivered into an orbit by “Progress M1-7”, was the first item in the Program of Scientific—Educational Micro-Satellite (PSEMS' 2002–2007, http://iki.cosmos.ru/kollibri/mission1_e.htm ) and designate the starting point of a series at perspective scientific—educational micro-satellites (SEMS, http://www.energia.ru/english/energia/sci-education/microsat/microsat-02.html ). In the “Kolibri-2000” project, several schools equipped by School Center of Reception of the Information (SCRI), participated, including Russian schools (Obninsk http://ftschool.obninsk.org ) and two Australian schools in Sydney, Knox Grammar School ( www.knox.nsw.edu.au ) and Ravenswood School for Girls ( www.ravenswood.nsw.edu.au ). The results of the “Kolibri-2000” first measurements on the orbit near the International Space Station will be submitted in this paper which include the ionosphere reaction during the April 2002 events, and address as understanding of the coupling and feedback in the Sun–Earth interaction.

  • results of in Flight Operation of scientific payload on micro satellite kolibri 2000
    Planetary and Space Science, 2005
    Co-Authors: S I Klimov, Yuri V Afanasyev, Egor A Grachev, O R Grigoryan, V A Grushin, Dmitri S Lysakov, M N Nozdrachev, S Savin
    Abstract:

    Abstract The realization of Russian–Australian scientific–educational micro-satellite Kolibri-2000 (weight of 20.5 kg), 20 March 2002, delivered into an orbit by “Progress M1-7”, was by the first item of the Program of Scientific–Educational Micro-Satellite (PSEMS’ 2002–2007) and designates a starting point of a series perspective scientific–educational micro-satellites (SEMS). In the Kolibri-2000 project, several schools equipped by School Center of Reception of the Information (SCRI), participate, including Russian schools (Obninsk) and two Australian schools in Sydney, Knox Grammar School and Ravenswood School for Girls. The results of the Kolibri-2000 first measurements on the orbit near International Space Station are presented in this paper which include the ionosphere reaction of April 2002 events. Our results address the understanding of the coupling and feedback in the Sun–Earth interaction in the space weather context.

Stefano Campanari - One of the best experts on this subject based on the ideXlab platform.

  • performance assessment of turbocharged pem fuel cell systems for civil aircraft onboard power production
    Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2008
    Co-Authors: Stefano Campanari, Andrea Beretti, Giampaolo Manzolini, Uwe Wollrab
    Abstract:

    Stefano Campanari Associate Professor e-mail: stefano.campanari@polimi.it Giampaolo Manzolini Research Engineer e-mail: giampaolo.manzolini@polimi.it Andrea Beretti Research Engineer Dipartimento di Energetica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy Uwe Wollrab Systems Engineering, Fuel Cell Systems Development, AIRBUS Deutschland Gmbh, 21129Hamburg, Germany e-mail: uwe.wollrab@airbus.com Performance Assessment of Turbocharged Pem Fuel Cell Systems for Civil Aircraft Onboard Power Production In recent years, civil aircraft projects are showing a continuous increase in the demand of onboard electrical power, both for the partial substitution of hydraulic or pneumatic controls and drives with electrical ones, and for the consumption of new auxiliary sys- tems developed in response to Flight safety and environmental control issues. Aiming to generate onboard power with low emissions and better efficiency, several manufacturers and research groups are considering the possibility to produce a relevant fraction of the electrical power required by the aircraft by a fuel cell system. The first step would be to replace the conventional auxiliary power unit (based on a small gas turbine) with a polymer electrolyte membrane (PEM) fuel cell type, which today is favored with respect to other fuel cell types; thanks to its higher power density and faster startup. The PEM fuel cell can be fed with a hydrogen rich gas coming from a fuel reformer, operating with the same jet fuel used by the aircraft, or relying on a dedicated hydrogen storage on- board. The cell requires also an air compression unit, where the temperature, pressure, and humidity of the air stream feeding the PEM unit during land and in-Flight Operation strongly influence the performance and the physical integrity of the fuel cell. In this work we consider different system architectures, where the air compression system may exploit an electrically driven compressor or a turbocharger unit. The compressor type and the system pressure level are optimized according to a fuel cell simulation model, which calculates the cell voltage and efficiency as a function of temperature and pressure, calibrated over the performances of real PEM cell components. The system performances are discussed under different operating conditions, covering ground Operation, and in- termediate and high altitude cruise conditions. The optimized configuration is selected, presenting energy balances and a complete thermodynamic analysis. 关DOI: 10.1115/1.2772636兴 Introduction New projects of civil aircrafts are in these years frequently influenced by a development strategy focusing on more electric aircraft 共MEA兲 or even all electric aircraft 共AEA兲 concepts. The partial substitution of conventional hydraulic or pneumatic con- trols and drives with electrical ones 共see Table 1兲, and the intro- duction of new auxiliary systems bring about an increase in on- board electric power consumption, reaching values around 560 kW for airplanes such as the B777 or A330/A340, and going toward 1.3– 1.5 MW for next generation aircrafts 关1–5兴. Furthermore, the possible elimination of power offtakes from the main engines would increase the nominal power output re- quired by a separated onboard electricity generator. It is well known that a fraction of electric power is generated on-board civil aircrafts by small turbine units, acting as auxiliary power units 共APUs兲. Such machines operate with simple cycle, uncooled Operation, low turbine inlet temperature 共TIT兲, and pres- sure ratio, generally with single stage radial compressor and a power output in the range of several tenth kilowatts and up to the hundred kilowatt scale. Their advantages include low weight, rapid startup, and robustness; disadvantages are primarily the low efficiency 共15–18%兲 and significant NO x and CO emissions. The Contributed by the International Gas Turbine Institute of ASME for publication in the J OURNAL OF E NGINEERING FOR G AS T URBINES AND P OWER . Manuscript received April 28, 2007; final manuscript received May 9, 2007; published online February 29, 2008. Review conducted by Dilip R. Ballal. Paper presented at the ASME Turbo Expo 2007: Land, Sea and Air 共GT2007兲, Montreal, Quebec, Canada, May 14–17, 2007, Paper No. GT2007-27658. possible removal of power offtakes from the main engines would increase the nominal power of the APU system, making more important to look for higher efficiency and lower pollution de- vices. Polymer electrolyte membrane fuel cells 共PEM FCs兲 on their own are widely experimented in prototypes and generally recog- nized very attractive for future application in the automotive field; thanks to their ability to generate electricity with high efficiency 共e.g., 50–55%兲 in tenth-kilowatt scale systems fed with hydrogen and operating at low temperatures 共60– 70° C兲. They also show a rather high power density 共in terms of kW/kg and kW/ dm 3 兲, fast startup, and negligible emissions. The quick development of this technology has suggested to consider their application also in the aeronautic field, within the perspective of a step by step develop- ment, which could also represent a new possible market for the beginning of their commercialization. The technology roadmap for this development includes several steps, where the first should be introducing a pure hydrogen PEM system with minor aircraft changes, aiming to provide a fraction of electric power 共well below the potential power requirements shown in Table 1兲 for auxiliary loads and emergency systems actually sustained by APUs and other generators 共for instance, the air turbine that is used to drive the pumps of the emergency hy- draulic circuit兲. Subsequent steps could involve the use of onboard reformers 关3兴 as well as different FC types with increasing power output. The concept of integrating a PEM unit onboard civil aircrafts has been already introduced in several works 关2,6,7兴, where the fuel cell has been generally considered as a device with assigned Journal of Engineering for Gas Turbines and Power Copyright © 2008 by ASME MARCH 2008, Vol. 130 / 021701-1 Downloaded From: http://gasturbinespower.asmedigitalcollection.asme.org/ on 02/17/2016 Terms of Use: http://www.asme.org/about-asme/terms-of-use

  • Performance assessment of turbocharged PEM fuel cell systems for civil aircraft onboard power production
    Volume 3: Turbo Expo 2007, 2007
    Co-Authors: Stefano Campanari, Andrea Beretti, Giampaolo Manzolini, Uwe Wollrab
    Abstract:

    In recent years, civil aircraft projects are showing a continuous increase in the demand of onboard electrical power, both for the partial substitution of hydraulic or pneumatic controls and drives with electrical ones, and for the consumption of new auxiliary systems developed in response to Flight safety and environmental control issues. Aiming to generate on-board power with low emissions and better efficiency, several manufacturers and research groups are considering the possibility to produce a relevant fraction of the electrical power required by the aircraft by a fuel cell system. The first step would be to replace the conventional auxiliary power unit (APU, based on a small gas turbine) with a Polymer Membrane fuel cell type (PEM), which today is favored with respect to other fuel cell types thanks to its higher power density and faster start-up. The PEM fuel cell can be fed with an hydrogen rich gas coming from a fuel reformer, operating with the same jet fuel used by the aircraft, or relying on a dedicated hydrogen storage onboard. The cell requires also an air compression unit, where the temperature, pressure and humidity of the air stream feeding the PEM unit during land and in-Flight Operation strongly influence the performance and the physical integrity of the fuel cell. In this work we consider different system architectures, where the air compression system may exploit an electrically driven compressor or a turbocharger unit. The compressor type and the system pressure level are optimized according to a fuel cell simulation model which calculates the cell voltage and efficiency as a function of temperature and pressure, calibrated over the performances of real PEM cell components. The system performances are discussed under different operating conditions, covering ground Operation, intermediate and high altitude cruise conditions. The optimized configuration is selected, presenting energy balances and a complete thermodynamic analysis.Copyright © 2007 by ASME