Author: Juan Esteban Gomez Herrera
Publisher: Cuvillier Verlag
ISBN: 3736963246
Category : Science
Languages : en
Pages : 368
Book Description
Zu den aktuellen Entwicklungen in der Raumfahrtindustrie zählen das stetig wachsende Interesse an miniaturisierten Satelliten sowie der immer häufigere Einsatz elektrischer Antriebssysteme zu allgemeinen Lage- und Bahnregelungszwecken. Die Entwicklung miniaturisierter Satelliten erfordert ihrerseits den Einsatz von Antriebssystemen, die sehr kleine und präzise zu steuernde Schubkräfte erzeugen. Vor diesem Hintergrund stellen elektrische Triebwerke eine attraktive Option dar, die Antriebsanforderungen von Satelliten sowohl in herkömmlichen als auch in miniaturisierten Größen langfristig zu erfüllen. Bei miniaturisierten Satelliten sind die Schubanforderungen oft mit niedrigen Treibstoff-Massenstromwerten und verhältnismäßig kleinen geometrischen charakteristischen Längen verbunden. Dies kann zu verdünnten Gaszuständen innerhalb der Triebwerksdüsen führen. Wegen der hohen Komplexität der Plasmaphänomene innerhalb elektrischer Triebwerke sowie der typischerweise hohen Rechenanforderungen, die mit der Plasmamodellierung einhergehen, werden elektrische Antriebssysteme oft auf Basis empirischer Modelle und experimenteller Daten entwickelt. Der Fokus der vorliegenden Arbeit liegt auf den oben beschriebenen Herausforderungen und den dazugehörigen Forschungsfeldern: der Untersuchung verdünnter Gaszustände in transsonischen Strömungen sowie der Entwicklung numerischer Modellierungsansätze zur Beschreibung des Plasmaverhaltens innerhalb elektrischer Antriebssysteme. New trends regarding fundamental design approaches of orbital spacecraft have been developing in the space industry in recent years. They include an increased interest in miniaturized satellites as well as a general rise in the use of electric propulsion systems for orbit and attitude control. The successful implementation of miniaturized satellites requires the use of propulsion devices able to provide small and precise thrust and impulse levels. One technical solution able to meet the requirements of both standard-sized as well as miniaturized spacecraft involves the use of highly efficient and precise electric propulsion systems. In the particular case of miniaturized satellites, the propulsion requirements are often associated with low propellant mass flow rates and small characteristic geometrical lengths, potentially leading to the appearance of rarefied conditions inside the nozzles of the propulsion devices. Because of the high complexity of the plasma phenomena taking place inside such systems and the usually very high computational requirements associated with their numerical modelling, electric propulsion systems for space applications are usually designed based on empirical models and experimental data. The present work focuses on two key aspects outlined above: rarefied gas conditions in transonic micronozzle flows as well as the numerical modelling of plasma phenomena inside electric propulsion systems.
Rarefied Gas Flows and Dynamic Plasma Phenomena in Electric Propulsion Systems
Author: Juan Esteban Gomez Herrera
Publisher: Cuvillier Verlag
ISBN: 3736963246
Category : Science
Languages : en
Pages : 368
Book Description
Zu den aktuellen Entwicklungen in der Raumfahrtindustrie zählen das stetig wachsende Interesse an miniaturisierten Satelliten sowie der immer häufigere Einsatz elektrischer Antriebssysteme zu allgemeinen Lage- und Bahnregelungszwecken. Die Entwicklung miniaturisierter Satelliten erfordert ihrerseits den Einsatz von Antriebssystemen, die sehr kleine und präzise zu steuernde Schubkräfte erzeugen. Vor diesem Hintergrund stellen elektrische Triebwerke eine attraktive Option dar, die Antriebsanforderungen von Satelliten sowohl in herkömmlichen als auch in miniaturisierten Größen langfristig zu erfüllen. Bei miniaturisierten Satelliten sind die Schubanforderungen oft mit niedrigen Treibstoff-Massenstromwerten und verhältnismäßig kleinen geometrischen charakteristischen Längen verbunden. Dies kann zu verdünnten Gaszuständen innerhalb der Triebwerksdüsen führen. Wegen der hohen Komplexität der Plasmaphänomene innerhalb elektrischer Triebwerke sowie der typischerweise hohen Rechenanforderungen, die mit der Plasmamodellierung einhergehen, werden elektrische Antriebssysteme oft auf Basis empirischer Modelle und experimenteller Daten entwickelt. Der Fokus der vorliegenden Arbeit liegt auf den oben beschriebenen Herausforderungen und den dazugehörigen Forschungsfeldern: der Untersuchung verdünnter Gaszustände in transsonischen Strömungen sowie der Entwicklung numerischer Modellierungsansätze zur Beschreibung des Plasmaverhaltens innerhalb elektrischer Antriebssysteme. New trends regarding fundamental design approaches of orbital spacecraft have been developing in the space industry in recent years. They include an increased interest in miniaturized satellites as well as a general rise in the use of electric propulsion systems for orbit and attitude control. The successful implementation of miniaturized satellites requires the use of propulsion devices able to provide small and precise thrust and impulse levels. One technical solution able to meet the requirements of both standard-sized as well as miniaturized spacecraft involves the use of highly efficient and precise electric propulsion systems. In the particular case of miniaturized satellites, the propulsion requirements are often associated with low propellant mass flow rates and small characteristic geometrical lengths, potentially leading to the appearance of rarefied conditions inside the nozzles of the propulsion devices. Because of the high complexity of the plasma phenomena taking place inside such systems and the usually very high computational requirements associated with their numerical modelling, electric propulsion systems for space applications are usually designed based on empirical models and experimental data. The present work focuses on two key aspects outlined above: rarefied gas conditions in transonic micronozzle flows as well as the numerical modelling of plasma phenomena inside electric propulsion systems.
Publisher: Cuvillier Verlag
ISBN: 3736963246
Category : Science
Languages : en
Pages : 368
Book Description
Zu den aktuellen Entwicklungen in der Raumfahrtindustrie zählen das stetig wachsende Interesse an miniaturisierten Satelliten sowie der immer häufigere Einsatz elektrischer Antriebssysteme zu allgemeinen Lage- und Bahnregelungszwecken. Die Entwicklung miniaturisierter Satelliten erfordert ihrerseits den Einsatz von Antriebssystemen, die sehr kleine und präzise zu steuernde Schubkräfte erzeugen. Vor diesem Hintergrund stellen elektrische Triebwerke eine attraktive Option dar, die Antriebsanforderungen von Satelliten sowohl in herkömmlichen als auch in miniaturisierten Größen langfristig zu erfüllen. Bei miniaturisierten Satelliten sind die Schubanforderungen oft mit niedrigen Treibstoff-Massenstromwerten und verhältnismäßig kleinen geometrischen charakteristischen Längen verbunden. Dies kann zu verdünnten Gaszuständen innerhalb der Triebwerksdüsen führen. Wegen der hohen Komplexität der Plasmaphänomene innerhalb elektrischer Triebwerke sowie der typischerweise hohen Rechenanforderungen, die mit der Plasmamodellierung einhergehen, werden elektrische Antriebssysteme oft auf Basis empirischer Modelle und experimenteller Daten entwickelt. Der Fokus der vorliegenden Arbeit liegt auf den oben beschriebenen Herausforderungen und den dazugehörigen Forschungsfeldern: der Untersuchung verdünnter Gaszustände in transsonischen Strömungen sowie der Entwicklung numerischer Modellierungsansätze zur Beschreibung des Plasmaverhaltens innerhalb elektrischer Antriebssysteme. New trends regarding fundamental design approaches of orbital spacecraft have been developing in the space industry in recent years. They include an increased interest in miniaturized satellites as well as a general rise in the use of electric propulsion systems for orbit and attitude control. The successful implementation of miniaturized satellites requires the use of propulsion devices able to provide small and precise thrust and impulse levels. One technical solution able to meet the requirements of both standard-sized as well as miniaturized spacecraft involves the use of highly efficient and precise electric propulsion systems. In the particular case of miniaturized satellites, the propulsion requirements are often associated with low propellant mass flow rates and small characteristic geometrical lengths, potentially leading to the appearance of rarefied conditions inside the nozzles of the propulsion devices. Because of the high complexity of the plasma phenomena taking place inside such systems and the usually very high computational requirements associated with their numerical modelling, electric propulsion systems for space applications are usually designed based on empirical models and experimental data. The present work focuses on two key aspects outlined above: rarefied gas conditions in transonic micronozzle flows as well as the numerical modelling of plasma phenomena inside electric propulsion systems.
Computational Science – ICCS 2009
Author: Gabrielle Allen
Publisher: Springer Science & Business Media
ISBN: 3642019692
Category : Computers
Languages : en
Pages : 1047
Book Description
“There is something fascinating about science. One gets such wholesale returns of conjecture out of such a tri?ing investment of fact. ” Mark Twain, Life on the Mississippi The challenges in succeeding with computational science are numerous and deeply a?ect all disciplines. NSF’s 2006 Blue Ribbon Panel of Simulation-Based 1 Engineering Science (SBES) states ‘researchers and educators [agree]: com- tational and simulation engineering sciences are fundamental to the security and welfare of the United States. . . We must overcome di?culties inherent in multiscale modeling, the development of next-generation algorithms, and the design. . . of dynamic data-driven application systems. . . We must determine better ways to integrate data-intensive computing, visualization, and simulation. - portantly,wemustoverhauloureducationalsystemtofostertheinterdisciplinary study. . . The payo?sformeeting these challengesareprofound. ’The International Conference on Computational Science 2009 (ICCS 2009) explored how com- tational sciences are not only advancing the traditional hard science disciplines, but also stretching beyond, with applications in the arts, humanities, media and all aspects of research. This interdisciplinary conference drew academic and industry leaders from a variety of ?elds, including physics, astronomy, mat- matics,music,digitalmedia,biologyandengineering. Theconferencealsohosted computer and computational scientists who are designing and building the - ber infrastructure necessary for next-generation computing. Discussions focused on innovative ways to collaborate and how computational science is changing the future of research. ICCS 2009: ‘Compute. Discover. Innovate. ’ was hosted by the Center for Computation and Technology at Louisiana State University in Baton Rouge.
Publisher: Springer Science & Business Media
ISBN: 3642019692
Category : Computers
Languages : en
Pages : 1047
Book Description
“There is something fascinating about science. One gets such wholesale returns of conjecture out of such a tri?ing investment of fact. ” Mark Twain, Life on the Mississippi The challenges in succeeding with computational science are numerous and deeply a?ect all disciplines. NSF’s 2006 Blue Ribbon Panel of Simulation-Based 1 Engineering Science (SBES) states ‘researchers and educators [agree]: com- tational and simulation engineering sciences are fundamental to the security and welfare of the United States. . . We must overcome di?culties inherent in multiscale modeling, the development of next-generation algorithms, and the design. . . of dynamic data-driven application systems. . . We must determine better ways to integrate data-intensive computing, visualization, and simulation. - portantly,wemustoverhauloureducationalsystemtofostertheinterdisciplinary study. . . The payo?sformeeting these challengesareprofound. ’The International Conference on Computational Science 2009 (ICCS 2009) explored how com- tational sciences are not only advancing the traditional hard science disciplines, but also stretching beyond, with applications in the arts, humanities, media and all aspects of research. This interdisciplinary conference drew academic and industry leaders from a variety of ?elds, including physics, astronomy, mat- matics,music,digitalmedia,biologyandengineering. Theconferencealsohosted computer and computational scientists who are designing and building the - ber infrastructure necessary for next-generation computing. Discussions focused on innovative ways to collaborate and how computational science is changing the future of research. ICCS 2009: ‘Compute. Discover. Innovate. ’ was hosted by the Center for Computation and Technology at Louisiana State University in Baton Rouge.
Laser Wakefield Electron Acceleration
Author: Karl Schmid
Publisher: Springer Science & Business Media
ISBN: 364219950X
Category : Science
Languages : en
Pages : 169
Book Description
This thesis covers the few-cycle laser-driven acceleration of electrons in a laser-generated plasma. This process, known as laser wakefield acceleration (LWFA), relies on strongly driven plasma waves for the generation of accelerating gradients in the vicinity of several 100 GV/m, a value four orders of magnitude larger than that attainable by conventional accelerators. This thesis demonstrates that laser pulses with an ultrashort duration of 8 fs and a peak power of 6 TW allow the production of electron energies up to 50 MeV via LWFA. The special properties of laser accelerated electron pulses, namely the ultrashort pulse duration, the high brilliance, and the high charge density, open up new possibilities in many applications of these electron beams.
Publisher: Springer Science & Business Media
ISBN: 364219950X
Category : Science
Languages : en
Pages : 169
Book Description
This thesis covers the few-cycle laser-driven acceleration of electrons in a laser-generated plasma. This process, known as laser wakefield acceleration (LWFA), relies on strongly driven plasma waves for the generation of accelerating gradients in the vicinity of several 100 GV/m, a value four orders of magnitude larger than that attainable by conventional accelerators. This thesis demonstrates that laser pulses with an ultrashort duration of 8 fs and a peak power of 6 TW allow the production of electron energies up to 50 MeV via LWFA. The special properties of laser accelerated electron pulses, namely the ultrashort pulse duration, the high brilliance, and the high charge density, open up new possibilities in many applications of these electron beams.
Gas Flows in Microsystems
Author: Lucien Baldas
Publisher: MDPI
ISBN: 3039215426
Category : Technology & Engineering
Languages : en
Pages : 220
Book Description
The last two decades have witnessed a rapid development of microelectromechanical systems (MEMS) involving gas microflows in various technical fields. Gas microflows can, for example, be observed in microheat exchangers designed for chemical applications or for cooling of electronic components, in fluidic microactuators developed for active flow control purposes, in micronozzles used for the micropropulsion of nano and picosats, in microgas chromatographs, analyzers or separators, in vacuum generators and in Knudsen micropumps, as well as in some organs-on-a-chip, such as artificial lungs. These flows are rarefied due to the small MEMS dimensions, and the rarefaction can be increased by low-pressure conditions. The flows relate to the slip flow, transition or free molecular regimes and can involve monatomic or polyatomic gases and gas mixtures. Hydrodynamics and heat and mass transfer are strongly impacted by rarefaction effects, and temperature-driven microflows offer new opportunities for designing original MEMS for gas pumping or separation. Accordingly, this Special Issue seeks to showcase research papers, short communications, and review articles that focus on novel theoretical and numerical models or data, as well as on new experimental results and technics, for improving knowledge on heat and mass transfer in gas microflows. Papers dealing with the development of original gas MEMS are also welcome.
Publisher: MDPI
ISBN: 3039215426
Category : Technology & Engineering
Languages : en
Pages : 220
Book Description
The last two decades have witnessed a rapid development of microelectromechanical systems (MEMS) involving gas microflows in various technical fields. Gas microflows can, for example, be observed in microheat exchangers designed for chemical applications or for cooling of electronic components, in fluidic microactuators developed for active flow control purposes, in micronozzles used for the micropropulsion of nano and picosats, in microgas chromatographs, analyzers or separators, in vacuum generators and in Knudsen micropumps, as well as in some organs-on-a-chip, such as artificial lungs. These flows are rarefied due to the small MEMS dimensions, and the rarefaction can be increased by low-pressure conditions. The flows relate to the slip flow, transition or free molecular regimes and can involve monatomic or polyatomic gases and gas mixtures. Hydrodynamics and heat and mass transfer are strongly impacted by rarefaction effects, and temperature-driven microflows offer new opportunities for designing original MEMS for gas pumping or separation. Accordingly, this Special Issue seeks to showcase research papers, short communications, and review articles that focus on novel theoretical and numerical models or data, as well as on new experimental results and technics, for improving knowledge on heat and mass transfer in gas microflows. Papers dealing with the development of original gas MEMS are also welcome.
Encyclopedia of Microfluidics and Nanofluidics
Author: Dongqing Li
Publisher: Springer Science & Business Media
ISBN: 0387324682
Category : Technology & Engineering
Languages : en
Pages : 2242
Book Description
Covering all aspects of transport phenomena on the nano- and micro-scale, this encyclopedia features over 750 entries in three alphabetically-arranged volumes including the most up-to-date research, insights, and applied techniques across all areas. Coverage includes electrical double-layers, optofluidics, DNC lab-on-a-chip, nanosensors, and more.
Publisher: Springer Science & Business Media
ISBN: 0387324682
Category : Technology & Engineering
Languages : en
Pages : 2242
Book Description
Covering all aspects of transport phenomena on the nano- and micro-scale, this encyclopedia features over 750 entries in three alphabetically-arranged volumes including the most up-to-date research, insights, and applied techniques across all areas. Coverage includes electrical double-layers, optofluidics, DNC lab-on-a-chip, nanosensors, and more.
Recent Advances in Theoretical, Applied, Computational and Experimental Mechanics
Author: B. N. Singh
Publisher: Springer Nature
ISBN: 9811511896
Category : Technology & Engineering
Languages : en
Pages : 454
Book Description
This volume contains selected papers presented at the 7th International Conference on Theoretical, Applied, Computational and Experimental Mechanics. The papers come from diverse disciplines, such as aerospace, civil, mechanical, and reliability engineering, physics, and navel architecture. The contents of this volume focus on different aspects of mechanics, namely, fluid mechanics, solid mechanics, flight mechanics, control, and propulsion. This volume will be of use to researchers interested in the study of mechanics across disciplines.
Publisher: Springer Nature
ISBN: 9811511896
Category : Technology & Engineering
Languages : en
Pages : 454
Book Description
This volume contains selected papers presented at the 7th International Conference on Theoretical, Applied, Computational and Experimental Mechanics. The papers come from diverse disciplines, such as aerospace, civil, mechanical, and reliability engineering, physics, and navel architecture. The contents of this volume focus on different aspects of mechanics, namely, fluid mechanics, solid mechanics, flight mechanics, control, and propulsion. This volume will be of use to researchers interested in the study of mechanics across disciplines.
Microscale and Nanoscale Heat Transfer
Author: Mourad Rebay
Publisher: CRC Press
ISBN: 1498736319
Category : Science
Languages : en
Pages : 499
Book Description
Microscale and Nanoscale Heat Transfer: Analysis, Design, and Applications features contributions from prominent researchers in the field of micro- and nanoscale heat transfer and associated technologies and offers a complete understanding of thermal transport in nano-materials and devices. Nanofluids can be used as working fluids in thermal system
Publisher: CRC Press
ISBN: 1498736319
Category : Science
Languages : en
Pages : 499
Book Description
Microscale and Nanoscale Heat Transfer: Analysis, Design, and Applications features contributions from prominent researchers in the field of micro- and nanoscale heat transfer and associated technologies and offers a complete understanding of thermal transport in nano-materials and devices. Nanofluids can be used as working fluids in thermal system
Micropropulsion for Small Spacecraft
Author: Michael Matthew Micci
Publisher: AIAA
ISBN: 9781600864391
Category : Microspacecraft
Languages : en
Pages : 520
Book Description
Publisher: AIAA
ISBN: 9781600864391
Category : Microspacecraft
Languages : en
Pages : 520
Book Description
Selected Papers from the ISTEGIM'19
Author: Lucien Baldas
Publisher: MDPI
ISBN: 3036501002
Category : Science
Languages : en
Pages : 180
Book Description
This Special Issue compiles 11 scientific works that were presented during the International Symposium on Thermal Effects in Gas Flow in Microscale, ISTEGIM 2019, held in Ettlingen, Germany, in October 2019. This symposium was organized in the framework of the MIGRATE Network, an H2020 Marie Skłodowska-Curie European Training Network that ran from November 2015 to October 2019 (www.migrate2015.eu). MIGRATE intends to address some of the current challenges in innovation that face the European industry with regard to heat and mass transfer in gas-based microscale processes. The papers collected in this book focus on fundamental issues that are encountered in microfluidic systems involving gases, such as the analysis of gas–surface interactions under rarefied conditions, the development of innovative integrated microsensors for airborne pollutants, new experimental techniques for the measurement of local quantities in miniaturized devices and heat transfer issues inside microchannels. The variety of topics addressed in this book emphasizes that multi-disciplinarity is the real common thread of the current applied research in microfluidics. We hope that this book will help to stimulate early-stage researchers who are working in microfluidics all around the world. This book is dedicated to them!
Publisher: MDPI
ISBN: 3036501002
Category : Science
Languages : en
Pages : 180
Book Description
This Special Issue compiles 11 scientific works that were presented during the International Symposium on Thermal Effects in Gas Flow in Microscale, ISTEGIM 2019, held in Ettlingen, Germany, in October 2019. This symposium was organized in the framework of the MIGRATE Network, an H2020 Marie Skłodowska-Curie European Training Network that ran from November 2015 to October 2019 (www.migrate2015.eu). MIGRATE intends to address some of the current challenges in innovation that face the European industry with regard to heat and mass transfer in gas-based microscale processes. The papers collected in this book focus on fundamental issues that are encountered in microfluidic systems involving gases, such as the analysis of gas–surface interactions under rarefied conditions, the development of innovative integrated microsensors for airborne pollutants, new experimental techniques for the measurement of local quantities in miniaturized devices and heat transfer issues inside microchannels. The variety of topics addressed in this book emphasizes that multi-disciplinarity is the real common thread of the current applied research in microfluidics. We hope that this book will help to stimulate early-stage researchers who are working in microfluidics all around the world. This book is dedicated to them!
Micro- and Nanoflows
Author: Valery Ya. Rudyak
Publisher: Springer
ISBN: 3319755234
Category : Science
Languages : en
Pages : 258
Book Description
This book describes physical, mathematical and experimental methods to model flows in micro- and nanofluidic devices. It takes in consideration flows in channels with a characteristic size between several hundreds of micrometers to several nanometers. Methods based on solving kinetic equations, coupled kinetic-hydrodynamic description, and molecular dynamics method are used. Based on detailed measurements of pressure distributions along the straight and bent microchannels, the hydraulic resistance coefficients are refined. Flows of disperse fluids (including disperse nanofluids) are considered in detail. Results of hydrodynamic modeling of the simplest micromixers are reported. Mixing of fluids in a Y-type and T-type micromixers is considered. The authors present a systematic study of jet flows, jets structure and laminar-turbulent transition. The influence of sound on the microjet structure is considered. New phenomena associated with turbulization and relaminarization of the mixing layer of microjets are discussed. Based on the conducted experimental investigations, the authors propose a chart of microjet flow regimes. When addressing the modeling of microflows of nanofluids, the authors show where conventional hydrodynamic approaches can be applied and where more complicated models are needed, and they analyze the hydrodynamic stability of the nanofluid flows. The last part of the book is devoted the statistical theory of the transport processes in fluids under confined conditions. The authors present the constitutive relations and the formulas for transport coefficients. In conclusion the authors present a rigorous analysis of the viscosity and diffusion in nanochannels and in porous media.
Publisher: Springer
ISBN: 3319755234
Category : Science
Languages : en
Pages : 258
Book Description
This book describes physical, mathematical and experimental methods to model flows in micro- and nanofluidic devices. It takes in consideration flows in channels with a characteristic size between several hundreds of micrometers to several nanometers. Methods based on solving kinetic equations, coupled kinetic-hydrodynamic description, and molecular dynamics method are used. Based on detailed measurements of pressure distributions along the straight and bent microchannels, the hydraulic resistance coefficients are refined. Flows of disperse fluids (including disperse nanofluids) are considered in detail. Results of hydrodynamic modeling of the simplest micromixers are reported. Mixing of fluids in a Y-type and T-type micromixers is considered. The authors present a systematic study of jet flows, jets structure and laminar-turbulent transition. The influence of sound on the microjet structure is considered. New phenomena associated with turbulization and relaminarization of the mixing layer of microjets are discussed. Based on the conducted experimental investigations, the authors propose a chart of microjet flow regimes. When addressing the modeling of microflows of nanofluids, the authors show where conventional hydrodynamic approaches can be applied and where more complicated models are needed, and they analyze the hydrodynamic stability of the nanofluid flows. The last part of the book is devoted the statistical theory of the transport processes in fluids under confined conditions. The authors present the constitutive relations and the formulas for transport coefficients. In conclusion the authors present a rigorous analysis of the viscosity and diffusion in nanochannels and in porous media.