The Experts below are selected from a list of 20472 Experts worldwide ranked by ideXlab platform

Seji Hata - One of the best experts on this subject based on the ideXlab platform.

  • A conceptual design of vectored water-Jet Propulsion system
    2009 IEEE International Conference on Mechatronics and Automation, ICMA 2009, 2009
    Co-Authors: Shuxiang Guo, Xichuan Lin, Seji Hata
    Abstract:

    This paper presents a novel vectored water-Jet Propulsion system which is supposed to be used on a spherical underwater vehicle. This system uses water-Jet as its Propulsion method and by using servo motors, the direction of output force can be regulated for different Propulsion tasks. This paper mainly focuses on the conceptual design of the system. To testify the availability of this design, a physical-based vectored water-Jet Propulsion system is developed using MATLAB/Simscape. Firstly, the servo motors module and flow rate control module are discussed respectively including modeling and simulation, and then a combined simulation of them is performed.

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

  • Jet Propulsion Laboratory: Outsider or insider?
    2019
    Co-Authors: Nasa
    Abstract:

    The working relationship between NASA and the Jet Propulsion Laboratory is examined in a historical context. The problems which developed due to the facility's close university association are addressed.

  • Publications of the Jet Propulsion Laboratory, 1992
    2019
    Co-Authors: Nasa
    Abstract:

    JPL Bibliography 39-33 describes and indexes by primary author the externally distributed technical reporting, released during calendar year 1992, that resulted from scientific and engineering work performed or managed by the Jet Propulsion Laboratory. Three classes of publications are included: (1) JPL Publication (92-series) in which the information is complete for a specific accomplishment; (2) articles from the quarterly Telecommunications and Data Acquisition (TDA) Progress Report (42-series) (each collection of articles in this class of publication presents a periodic survey of current accomplishments by the Deep Space Network as well as other developments in Earth-based radio technology); and (3) articles published in the open literature.

  • Publications of the Jet Propulsion Laboratory: 1990 and 1991
    2019
    Co-Authors: Nasa
    Abstract:

    JPL Bibliography 39-32 describes and indexes by primary author the externally distributed technical reporting, released during calendar years 1990 and 1991, that resulted from scientific and engineering work performed or managed by the Jet Propulsion Laboratory (JPL). Three classes of publications are included: (1) JPL publications (90- and 91-series) in which the information is complete for a specific accomplishment; (2) articles from the quarterly Telecommunications and Data Acquisition (TDA) Progress Report (42-series); and (3) articles published in the open literature.

  • Publications of the Jet Propulsion Laboratory 1983
    2013
    Co-Authors: Nasa
    Abstract:

    The Jet Propulsion Laboratory (JPL) bibliography describes and indexes by primary author the externally distributed technical reporting, released during calendar year 1983, that resulted from scientific and engineering work performed, or managed, by the Jet Propulsion Laboratory. Three classes of publications are included. JPL Publication (81-,82-,83-series, etc.), in which the information is complete for a specific accomplishment, articles published in the open literature, and articles from the quarterly telecommunications and Data Acquisition (TDA) Progress Report (42-series) are included. Each collection of articles in this class of publication presents a periodic survey of current accomplishments by the Deep Space Network as well as other developments in Earth-based radio technology.

  • Activities of the Jet Propulsion Laboratory
    2013
    Co-Authors: Nasa
    Abstract:

    Work accomplished by the Jet Propulsion Laboratory (JPL) under contract to NASA in 1985 is described. The work took place in the areas of flight projects, space science, geodynamics, materials science, advanced technology, defense and civil programs, telecommunications systems, and institutional activities.

Shuxiang Guo - One of the best experts on this subject based on the ideXlab platform.

  • A conceptual design of vectored water-Jet Propulsion system
    2009 IEEE International Conference on Mechatronics and Automation, ICMA 2009, 2009
    Co-Authors: Shuxiang Guo, Xichuan Lin, Seji Hata
    Abstract:

    This paper presents a novel vectored water-Jet Propulsion system which is supposed to be used on a spherical underwater vehicle. This system uses water-Jet as its Propulsion method and by using servo motors, the direction of output force can be regulated for different Propulsion tasks. This paper mainly focuses on the conceptual design of the system. To testify the availability of this design, a physical-based vectored water-Jet Propulsion system is developed using MATLAB/Simscape. Firstly, the servo motors module and flow rate control module are discussed respectively including modeling and simulation, and then a combined simulation of them is performed.

Xichuan Lin - One of the best experts on this subject based on the ideXlab platform.

  • A conceptual design of vectored water-Jet Propulsion system
    2009 IEEE International Conference on Mechatronics and Automation, ICMA 2009, 2009
    Co-Authors: Shuxiang Guo, Xichuan Lin, Seji Hata
    Abstract:

    This paper presents a novel vectored water-Jet Propulsion system which is supposed to be used on a spherical underwater vehicle. This system uses water-Jet as its Propulsion method and by using servo motors, the direction of output force can be regulated for different Propulsion tasks. This paper mainly focuses on the conceptual design of the system. To testify the availability of this design, a physical-based vectored water-Jet Propulsion system is developed using MATLAB/Simscape. Firstly, the servo motors module and flow rate control module are discussed respectively including modeling and simulation, and then a combined simulation of them is performed.

Laura Miller - One of the best experts on this subject based on the ideXlab platform.

  • Reynolds number limits for Jet Propulsion: a numerical study of simplified jellyfish.
    Journal of Theoretical Biology, 2011
    Co-Authors: Gregory Herschlag, Laura Miller
    Abstract:

    Abstract The Scallop theorem states that reciprocal methods of locomotion, such as Jet Propulsion or paddling, will not work in Stokes flow (Reynolds number=0). In nature the effective limit of Jet Propulsion is still in the range where inertial forces are significant. It appears that almost all animals that use Jet Propulsion swim at Reynolds numbers (Re) of about 5 or more. Juvenile squid and octopods hatch from the egg already swimming in this inertial regime. Juvenile jellyfish, or ephyrae, break off from polyps swimming at Re greater than 5. Many other organisms, such as scallops, rarely swim at Re less than 100. The limitations of Jet Propulsion at intermediate Re is explored here using the immersed boundary method to solve the 2D Navier–Stokes equations coupled to the motion of a simplified jellyfish. The contraction and expansion kinematics are prescribed, but the forward and backward swimming motions of the idealized jellyfish are emergent properties determined by the resulting fluid dynamics. Simulations are performed for both an oblate bell shape using a paddling mode of swimming and a prolate bell shape using Jet Propulsion. Average forward velocities and work put into the system are calculated for Re between 1 and 320. The results show that forward velocities rapidly decay with decreasing Re for all bell shapes when Re 10 . Similarly, the work required to generate the pulsing motion increases significantly for Re 10 . When compared to actual organisms, the swimming velocities and vortex separation patterns for the model prolate agree with those observed in Nemopsis bachei. The forward swimming velocities of the model oblate jellyfish after two pulse cycles are comparable to those reported for Aurelia aurita, but discrepancies are observed in the vortex dynamics between when the 2D model oblate jellyfish and the organism. This discrepancy is likely due to a combination of the differences between the 3D reality of the jellyfish and the 2D simplification, as well as the rigidity of the time varying geometry imposed by the idealized model.

  • Reynolds number limits for Jet Propulsion: A numerical study of simplified jellyfish
    arXiv: Fluid Dynamics, 2010
    Co-Authors: Gregory Herschlag, Laura Miller
    Abstract:

    The Scallop Theorem states that reciprocal methods of locomotion, such as Jet Propulsion or paddling, will not work in Stokes flow (Reynolds number = 0). In nature the effective limit of Jet Propulsion is still in the range where inertial forces are significant. It appears that almost all animals that use Jet Propulsion swim at Reynolds numbers (Re) of about 5 or more. Juvenile squid and octopods hatch from the egg already swimming in this inertial regime. The limitations of Jet Propulsion at intermediate Re is explored here using the immersed boundary method to solve the two-dimensional Navier Stokes equations coupled to the motion of a simplified jellyfish. The contraction and expansion kinematics are prescribed, but the forward and backward swimming motions of the idealized jellyfish are emergent properties determined by the resulting fluid dynamics. Simulations are performed for both an oblate bell shape using a paddling mode of swimming and a prolate bell shape using Jet Propulsion. Average forward velocities and work put into the system are calculated for Reynolds numbers between 1 and 320. The results show that forward velocities rapidly decay with decreasing Re for all bell shapes when Re < 10. Similarly, the work required to generate the pulsing motion increases significantly for Re < 10. When compared actual organisms, the swimming velocities and vortex separation patterns for the model prolate agree with those observed in Nemopsis bachei. The forward swimming velocities of the model oblate jellyfish after two pulse cycles are comparable to those reported for Aurelia aurita, but discrepancies are observed in the vortex dynamics between when the 2D model oblate jellyfish and the organism.