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Vicky Kalogera - One of the best experts on this subject based on the ideXlab platform.
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angular Momentum Exchange in white dwarf binaries accreting through direct impact
The Astrophysical Journal, 2014Co-Authors: Jeremy Sepinsky, Vicky KalogeraAbstract:We examine the Exchange of angular Momentum between the component spins and the orbit in semi-detached double white dwarf binaries undergoing mass transfer through direct impact of the transfer stream. We approximate the stream as a series of discrete massive particles ejected in the ballistic limit at the inner Lagrangian point of the donor toward the accretor. This work improves upon similar earlier studies in a number of ways. First, we self-consistently calculate the total angular Momentum of the orbit at all times. This includes changes in the orbital angular Momentum during the ballistic trajectory of the ejected mass, as well as changes during the ejection/accretion due to the radial component of the particle's velocity. Second, we calculate the particle's ballistic trajectory for each system, which allows us to determine the precise position and velocity of the particle upon accretion. We can then include specific information about the radius of the accretor as well as the angle of impact. Finally, we ensure that the total angular Momentum is conserved, which requires the donor star spin to vary self-consistently. With these improvements, we calculate the angular Momentum change of the orbit and each binary component across the entire parameter space of direct impact double white dwarf binary systems. We find a significant decrease in the amount of angular Momentum removed from the orbit during mass transfer, as well as cases where this process increases the angular Momentum of the orbit at the expense of the spin angular Momentum of the donor. We conclude that, unlike earlier claims in the literature, mass transfer through direct impact need not destabilize the binary and that the quantity and sign of the orbital angular Momentum transfer depends on the binary properties, particularly the masses of the double white dwarf binary component stars. This stabilization may significantly impact the population synthesis calculations of the expected numbers of events/systems for which double white dwarfs may be a progenitor, e.g., Type Ia supernovae, Type.Ia supernovae, and AM CVn.
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angular Momentum Exchange in white dwarf binaries accreting through direct impact
arXiv: Solar and Stellar Astrophysics, 2014Co-Authors: Jeremy Sepinsky, Vicky KalogeraAbstract:We examine the Exchange of angular Momentum between the component spins and the orbit in semi-detached double white dwarf binaries undergoing mass transfer through direct impact of the transfer stream. We approximate the stream as a series of discrete massive particles ejected in the ballistic limit at the inner Lagrangian point of the donor toward the accretor. This work improves upon similar earlier studies in a number of ways. First, we self-consistently calculate the total angular Momentum of the orbit at all times. This includes changes in the orbital angular Momentum during the ballistic trajectory of the ejected mass, as well as changes during the ejection/accretion due to the radial component of the particle's velocity. Second, we calculate the particle's ballistic trajectory for each system, which allows us to determine the precise position and velocity of the particle upon accretion. We can then include specific information about the radius of the accretor as well as the angle of impact. Finally, we ensure that the total angular Momentum is conserved, which requires the donor star spin to vary self-consistently. We calculate the angular Momentum change of the orbit and each binary component across the entire parameter space of direct impact double white dwarf binaries. We find a significant decrease in the amount of angular Momentum removed from the orbit during mass transfer, as well as cases where this process increases the angular Momentum of the orbit at the expense of the spin angular Momentum of the donor. We conclude that, unlike earlier claims in the literature, mass transfer through direct impact need not destabilize the binary and that the quantity and sign of the orbital angular Momentum transfer depends on the binary properties. This stabilization may significantly impact the population synthesis calculations of double white dwarf progenitors.
Nathaniel J Fisch - One of the best experts on this subject based on the ideXlab platform.
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magnetogenesis by wave driven Momentum Exchange
The Astrophysical Journal, 2020Co-Authors: Ian Ochs, Nathaniel J FischAbstract:When multiple species interact with an electrostatic ion acoustic wave, they can Exchange Momentum, despite the lack of Momentum in the field itself. The resulting force on the electrons can have a curl, and thus give rise to compensating electric fields with curl on magnetohydrodynamic timescales. As a result, a magnetic field can be generated. Surprisingly, in some astrophysical settings, this mechanism can seed magnetic fields with growth rates even larger than through the traditional Biermann battery.
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Momentum Exchange current drive by electrostatic waves in an unmagnetized collisionless plasma
Physics of Plasmas, 2020Co-Authors: Ian Ochs, Nathaniel J FischAbstract:For a planar electrostatic wave interacting with a single species in a collisionless plasma, Momentum conservation implies current conservation. However, when multiple species interact with the wave, they can Exchange Momentum, leading to current drive. A simple, general formula for this driven current is derived. As examples, we show how currents can be driven for Langmuir waves in electron–positron–ion plasmas, and for ion-acoustic waves in electron–ion plasmas.
Jeremy Sepinsky - One of the best experts on this subject based on the ideXlab platform.
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angular Momentum Exchange in white dwarf binaries accreting through direct impact
The Astrophysical Journal, 2014Co-Authors: Jeremy Sepinsky, Vicky KalogeraAbstract:We examine the Exchange of angular Momentum between the component spins and the orbit in semi-detached double white dwarf binaries undergoing mass transfer through direct impact of the transfer stream. We approximate the stream as a series of discrete massive particles ejected in the ballistic limit at the inner Lagrangian point of the donor toward the accretor. This work improves upon similar earlier studies in a number of ways. First, we self-consistently calculate the total angular Momentum of the orbit at all times. This includes changes in the orbital angular Momentum during the ballistic trajectory of the ejected mass, as well as changes during the ejection/accretion due to the radial component of the particle's velocity. Second, we calculate the particle's ballistic trajectory for each system, which allows us to determine the precise position and velocity of the particle upon accretion. We can then include specific information about the radius of the accretor as well as the angle of impact. Finally, we ensure that the total angular Momentum is conserved, which requires the donor star spin to vary self-consistently. With these improvements, we calculate the angular Momentum change of the orbit and each binary component across the entire parameter space of direct impact double white dwarf binary systems. We find a significant decrease in the amount of angular Momentum removed from the orbit during mass transfer, as well as cases where this process increases the angular Momentum of the orbit at the expense of the spin angular Momentum of the donor. We conclude that, unlike earlier claims in the literature, mass transfer through direct impact need not destabilize the binary and that the quantity and sign of the orbital angular Momentum transfer depends on the binary properties, particularly the masses of the double white dwarf binary component stars. This stabilization may significantly impact the population synthesis calculations of the expected numbers of events/systems for which double white dwarfs may be a progenitor, e.g., Type Ia supernovae, Type.Ia supernovae, and AM CVn.
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angular Momentum Exchange in white dwarf binaries accreting through direct impact
arXiv: Solar and Stellar Astrophysics, 2014Co-Authors: Jeremy Sepinsky, Vicky KalogeraAbstract:We examine the Exchange of angular Momentum between the component spins and the orbit in semi-detached double white dwarf binaries undergoing mass transfer through direct impact of the transfer stream. We approximate the stream as a series of discrete massive particles ejected in the ballistic limit at the inner Lagrangian point of the donor toward the accretor. This work improves upon similar earlier studies in a number of ways. First, we self-consistently calculate the total angular Momentum of the orbit at all times. This includes changes in the orbital angular Momentum during the ballistic trajectory of the ejected mass, as well as changes during the ejection/accretion due to the radial component of the particle's velocity. Second, we calculate the particle's ballistic trajectory for each system, which allows us to determine the precise position and velocity of the particle upon accretion. We can then include specific information about the radius of the accretor as well as the angle of impact. Finally, we ensure that the total angular Momentum is conserved, which requires the donor star spin to vary self-consistently. We calculate the angular Momentum change of the orbit and each binary component across the entire parameter space of direct impact double white dwarf binaries. We find a significant decrease in the amount of angular Momentum removed from the orbit during mass transfer, as well as cases where this process increases the angular Momentum of the orbit at the expense of the spin angular Momentum of the donor. We conclude that, unlike earlier claims in the literature, mass transfer through direct impact need not destabilize the binary and that the quantity and sign of the orbital angular Momentum transfer depends on the binary properties. This stabilization may significantly impact the population synthesis calculations of double white dwarf progenitors.
Ian Ochs - One of the best experts on this subject based on the ideXlab platform.
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magnetogenesis by wave driven Momentum Exchange
The Astrophysical Journal, 2020Co-Authors: Ian Ochs, Nathaniel J FischAbstract:When multiple species interact with an electrostatic ion acoustic wave, they can Exchange Momentum, despite the lack of Momentum in the field itself. The resulting force on the electrons can have a curl, and thus give rise to compensating electric fields with curl on magnetohydrodynamic timescales. As a result, a magnetic field can be generated. Surprisingly, in some astrophysical settings, this mechanism can seed magnetic fields with growth rates even larger than through the traditional Biermann battery.
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Momentum Exchange current drive by electrostatic waves in an unmagnetized collisionless plasma
Physics of Plasmas, 2020Co-Authors: Ian Ochs, Nathaniel J FischAbstract:For a planar electrostatic wave interacting with a single species in a collisionless plasma, Momentum conservation implies current conservation. However, when multiple species interact with the wave, they can Exchange Momentum, leading to current drive. A simple, general formula for this driven current is derived. As examples, we show how currents can be driven for Langmuir waves in electron–positron–ion plasmas, and for ion-acoustic waves in electron–ion plasmas.
Lovely Son - One of the best experts on this subject based on the ideXlab platform.
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A Novel Boat Shock Vibration Control using Momentum Exchange Principle with Pre-Straining Spring Mechanism
International Journal of Automotive and Mechanical Engineering, 2020Co-Authors: Lovely Son, J. Malta, Eko Satria, B. Yuliandra, Hirohide MatsuhisaAbstract:This research proposes a new method for boat impact vibration attenuation using the Exchange of Momentum principle with a pre-straining spring mechanism. The boat dynamic is modeled using a hinged-supported beam structure. The wave excitation on the boat hull is expressed using one degree of freedom spring-mass system. The simulation study is performed to evaluate the impact damper performance in reducing the boat shock response. Two kinds of Momentum Exchange impact damper i.e., without and with pre-straining spring mechanism, are evaluated. The simulation results show that the impact damper with pre-straining spring mechanism (PSMEID) is better than the passive Momentum Exchange impact damper (PMEID) in reducing the boat shock vibration response
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A new concept for UAV landing gear shock vibration control using pre-straining spring Momentum Exchange impact damper
Journal of Vibration and Control, 2016Co-Authors: Lovely Son, Mulyadi Bur, Meifal RusliAbstract:This study proposes a new method for reducing the shock vibration response of an Unmanned Aerial Vehicle (UAV) during the landing process by means of the Momentum Exchange principle (MEID). The per...
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experiment of shock vibration control using active Momentum Exchange impact damper
Journal of Vibration and Control, 2010Co-Authors: Lovely Son, Susumu Hara, Keisuke Yamada, Hiroshi MatsuhisaAbstract:In the authors’ previous study, we proposed a novel shock vibration control method using the active Momentum Exchange impact damper (AMEID). By using this method, the shock vibration of the vibratory system is greatly reduced by transferring part of its Momentum to the damper mass. This feature is effective for suppressing the first large peak value of the acceleration response due to a shock load. However, the validity of AMEID for actual implementations has not yet been investigated. In this paper, the active control of shock vibration using AMEID under real conditions is evaluated by simulation and experiment. A one-degree-of-freedom vibratory system is used as the controlled object. The controller is designed using the linear quadratic regulator optimal control theory. Reductions in the acceleration response and transmitted force to the base are investigated using simulations. Experiments are carried out to verify the simulation results.
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energy transfer in a three body Momentum Exchange impact damper
Journal of System Design and Dynamics, 2008Co-Authors: Lovely Son, Hiroshi Matsuhisa, Hideo UtsunoAbstract:Impact vibration such as a floor vibration caused by jumping of children or vibration of a press machine is very important engineering problem. The Momentum Exchange impact damper has been proposed to solve these problems. The basic principle of this damper is based on the energy transfer on collision of three body systems. However energy or Momentum transfer at the impact is not explained theoretically. This paper considers the energy transfer incurred during collisions in three body systems. The three body systems considered herein consists of an impact mass, a main body and an absorber mass. When the impact mass collides with the main body, part of its kinetic energy is transferred to the main body. When the main body simultaneously collides with the absorber mass, part of the kinetic energy of the main body is transferred to the absorber mass. Consequently, the main body receives a small amount of shock and it is possible to keep the main body nearly stationary. In this study, the influence of contact frequency and natural frequency of the system on the energy transfer during collision is analyzed. A theoretical model is developed to analyze the effect of various system parameters. It is shown that the maximum transfer of energy that can be obtained occurs when the contact frequencies are the same. The theoretical analysis is validated with experimental results.
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reduction of floor shock vibration by active Momentum Exchange impact damper
Journal of System Design and Dynamics, 2008Co-Authors: Lovely Son, Susumu Hara, Keisuke Yamada, Hideo Utsuno, Hiroshi MatsuhisaAbstract:This paper proposes an active control type of Momentum Exchange impact damper (AMEID) and its application to reducing shock vibration of the floor. The floor is modeled as a one-degree-of-freedom system. The active component of AMEID is realized by using a linear motor. The controller design of AMEID is based on the LQR optimal control theory. The simulation results show that the performance of AMEID is not affected by the mass ratio. In addition, the performance of AMEID is compared with the conventional passive Momentum Exchange impact damper (PMEID), the active mass damper (AMD) and the conventional active control method in reducing the floor shock vibration. It is shown that the shock reduction performance obtained by AMEID is larger than that obtained by PMEID. The power consumption and the stroke of the actuator for AMEID are lower than those of AMD. Furthermore, the transmitted force obtained by AMEID is smaller than that of the conventional active control.
