The Experts below are selected from a list of 11868 Experts worldwide ranked by ideXlab platform

Cal, Raúl Bayoán - One of the best experts on this subject based on the ideXlab platform.

  • Lagrangian diffusion properties of a free shear turbulent jet
    'Cambridge University Press (CUP)', 2021
    Co-Authors: Viggiano Bianca, Basset Thomas, Solovitz Stephen, Barois Thomas, Gibert Mathieu, Mordant Nicolas, Chevillard Laurent, Volk Romain, Bourgoin Mickaël, Cal, Raúl Bayoán
    Abstract:

    International audienceA Lagrangian experimental study of an axisymmetric turbulent water jet is performed to investigate the highly anisotropic and inhomogeneous flow field. Measurements are conducted within a Lagrangian exploration module, an icosahedron apparatus, to facilitate optical access of three cameras. Stereoscopic particle tracking velocimetry results in three-component tracks of position, velocity and acceleration of the tracer particles within the vertically oriented jet with a Taylor-based Reynolds number Reλ≃230. Analysis is performed at seven locations from 15 diameters up to 45 diameters downstream. Eulerian Analysis is first carried out to obtain critical parameters of the jet and relevant scales, namely the Kolmogorov and large (integral) scales as well as the energy dissipation rate. Lagrangian statistical Analysis is then performed on velocity components stationarised following methods inspired by Batchelor (J. Fluid Mech., vol. 3, 1957, pp. 67–80), which aim to extend stationary Lagrangian theory of turbulent diffusion by Taylor to the case of self-similar flows. The evolution of typical Lagrangian scaling parameters as a function of the developing jet is explored and results show validation of the proposed stationarisation. The universal scaling constant C0 (for the Lagrangian second-order structure function), as well as Eulerian and Lagrangian integral time scales, are discussed in this context. Constant C0 is found to converge to a constant value (of the order of C0=3) within 30 diameters downstream of the nozzle. Finally, the occurrence of finite particle size effects is investigated through consideration of acceleration-dependent quantitie

  • Lagrangian Diffusion Properties of a Free Shear Turbulent Jet
    PDXScholar, 2021
    Co-Authors: Viggiano, Bianca F., Basset Thomas, Solovitz Stephen, Barois Thomas, Gibert Mathieu, Mordant Nicolas, Chevillard Laurent, Volk Romain, Bourgoin Mickaël, Cal, Raúl Bayoán
    Abstract:

    A Lagrangian experimental study of an axisymmetric turbulent water jet is performed to investigate the highly anisotropic and inhomogeneous flow field. Measurements are conducted within a Lagrangian exploration module, an icosahedron apparatus, to facilitate optical access of three cameras. Stereoscopic particle tracking velocimetry results in three-component tracks of position, velocity and acceleration of the tracer particles within the vertically oriented jet with a Taylor-based Reynolds number Reλ≃230. Analysis is performed at seven locations from 15 diameters up to 45 diameters downstream. Eulerian Analysis is first carried out to obtain critical parameters of the jet and relevant scales, namely the Kolmogorov and large (integral) scales as well as the energy dissipation rate. Lagrangian statistical Analysis is then performed on velocity components stationarised following methods inspired by Batchelor (J. Fluid Mech., vol. 3, 1957, pp. 67–80), which aim to extend stationary Lagrangian theory of turbulent diffusion by Taylor to the case of self-similar flows. The evolution of typical Lagrangian scaling parameters as a function of the developing jet is explored and results show validation of the proposed stationarisation. The universal scaling constant C0 (for the Lagrangian second-order structure function), as well as Eulerian and Lagrangian integral time scales, are discussed in this context. Constant C0 is found to converge to a constant value (of the order of C0=3) within 30 diameters downstream of the nozzle. Finally, the occurrence of finite particle size effects is investigated through consideration of acceleration-dependent quantities

  • Lagrangian diffusion properties of a free shear turbulent jet
    2021
    Co-Authors: Viggiano Bianca, Basset Thomas, Solovitz Stephen, Barois Thomas, Gibert Mathieu, Mordant Nicolas, Chevillard Laurent, Volk Romain, Bourgoin Mickaël, Cal, Raúl Bayoán
    Abstract:

    A Lagrangian experimental study of an axisymmetric turbulent water jet is performed to investigate the highly anisotropic and inhomogeneous flow field. The measurements were conducted within a Lagrangian exploration module, an icosahedron apparatus, to facilitate optical access of three cameras. The stereoscopic particle tracking velocimetry results in three component tracks of position, velocity and acceleration of the tracer particles within the vertically-oriented jet with a Taylor-based Reynolds number $\mathcal R_\lambda \simeq 230$. Analysis is performed at seven locations from 15 diameters up to 45 diameters downstream. Eulerian Analysis is first carried out to obtain critical parameters of the jet and relevant scales, namely the Kolmogorov and large turnover (integral) scales as well as the energy dissipation rate. Lagrangian statistical Analysis is then performed on velocity components stationarised following methods inspired by Batchelor (\textit{J. Fluid Mech.}, vol. 3, 1957, pp. 67-80) which aim to extend stationary Lagrangian theory of turbulent diffusion by Taylor to the case of self-similar flows. The evolution of typical Lagrangian scaling parameters as a function of the developing jet is explored and results show validation of the proposed stationarisation. The universal scaling constant $C_0$ (for the Lagrangian second-order structure function), as well as Eulerian and Lagrangian integral time scales are discussed in this context. $C_0$ is found to converge to a constant value (of the order of $C_0 = 3$) within 30 diameters downstream of the nozzle. Finally, the existence of finite particle size effects are investigated through consideration of acceleration dependent quantities

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

  • nonlinear analytic solution of Eulerian beam wave interaction theory considering harmonic interaction of traveling wave tube amplifiers
    IEEE Transactions on Microwave Theory and Techniques, 2019
    Co-Authors: Yulu Hu, Quan Hu, Bin Li
    Abstract:

    In this paper, a novel Eulerian nonlinear beam-wave interaction (BWI) theory considering harmonic interaction of a helix traveling-wave tube (TWT) is developed. Derived from this Eulerian model, the novel Eulerian nonlinear analytic solutions (the fourth-order analytic solution of fundamental and the second-order analytic solution of harmonic) are first obtained by the method of successive approximation. The analytic relationships between electric fields of fundamental/harmonic frequencies and electron phases are also found. Then, the Eulerian nonlinear analytic solutions and Eulerian nonlinear BWI theory are compared to a Lagrangian theory. C-band and Ku-band helix TWTs based on a single pitch section are included in the simulation. It is found that the Eulerian nonlinear analytic solutions and Eulerian nonlinear BWI theory agree well with the Lagrangian theory at 1-dB gain compression point. Interestingly, the saturation effects caused by electron overtaking cannot be found by the traditional Eulerian Analysis but can be described by the Eulerian nonlinear analytic solutions and Eulerian nonlinear BWI theory. Moreover, Eulerian nonlinear analytic solutions are simpler and more accurately than existing approaches and, thus, allow analytical progress. This paper confirms that the Eulerian nonlinear analytic solutions can outperform the previous proposals.

Thomas J Hanratty - One of the best experts on this subject based on the ideXlab platform.

  • concentration profiles in a turbulent suspension when gravity is not affecting deposition
    International Journal of Multiphase Flow, 2004
    Co-Authors: Yoichi Mito, Thomas J Hanratty
    Abstract:

    Abstract An idealized representation of the dispersed flow in a fully-developed annular pattern is considered for the case of zero gravitational effects. The walls of a two-dimensional channel are represented as presenting arrays of infinitesimal particle sources. The behavior of a single source is described by modeling the fluid turbulence seen by the particles with a modified Langevin equation. By carrying out the calculations over a wide range of dimensionless time constants the deposition process could be followed, as the controlling mechanism changed from Brownian diffusion, to turbulent diffusion, to free-flight, to unidirectional non-turbulent trajectories. The calculation of local mean particle accelerations allowed a direct evaluation of the turbophoretic velocity. A consideration of the concentration profiles indicates that a Boussinesq representation of turbulent mixing is not valid in an Eulerian Analysis.

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

  • Lagrangian diffusion properties of a free shear turbulent jet
    'Cambridge University Press (CUP)', 2021
    Co-Authors: Viggiano Bianca, Basset Thomas, Solovitz Stephen, Barois Thomas, Gibert Mathieu, Mordant Nicolas, Chevillard Laurent, Volk Romain, Bourgoin Mickaël, Cal, Raúl Bayoán
    Abstract:

    International audienceA Lagrangian experimental study of an axisymmetric turbulent water jet is performed to investigate the highly anisotropic and inhomogeneous flow field. Measurements are conducted within a Lagrangian exploration module, an icosahedron apparatus, to facilitate optical access of three cameras. Stereoscopic particle tracking velocimetry results in three-component tracks of position, velocity and acceleration of the tracer particles within the vertically oriented jet with a Taylor-based Reynolds number Reλ≃230. Analysis is performed at seven locations from 15 diameters up to 45 diameters downstream. Eulerian Analysis is first carried out to obtain critical parameters of the jet and relevant scales, namely the Kolmogorov and large (integral) scales as well as the energy dissipation rate. Lagrangian statistical Analysis is then performed on velocity components stationarised following methods inspired by Batchelor (J. Fluid Mech., vol. 3, 1957, pp. 67–80), which aim to extend stationary Lagrangian theory of turbulent diffusion by Taylor to the case of self-similar flows. The evolution of typical Lagrangian scaling parameters as a function of the developing jet is explored and results show validation of the proposed stationarisation. The universal scaling constant C0 (for the Lagrangian second-order structure function), as well as Eulerian and Lagrangian integral time scales, are discussed in this context. Constant C0 is found to converge to a constant value (of the order of C0=3) within 30 diameters downstream of the nozzle. Finally, the occurrence of finite particle size effects is investigated through consideration of acceleration-dependent quantitie

  • Lagrangian Diffusion Properties of a Free Shear Turbulent Jet
    PDXScholar, 2021
    Co-Authors: Viggiano, Bianca F., Basset Thomas, Solovitz Stephen, Barois Thomas, Gibert Mathieu, Mordant Nicolas, Chevillard Laurent, Volk Romain, Bourgoin Mickaël, Cal, Raúl Bayoán
    Abstract:

    A Lagrangian experimental study of an axisymmetric turbulent water jet is performed to investigate the highly anisotropic and inhomogeneous flow field. Measurements are conducted within a Lagrangian exploration module, an icosahedron apparatus, to facilitate optical access of three cameras. Stereoscopic particle tracking velocimetry results in three-component tracks of position, velocity and acceleration of the tracer particles within the vertically oriented jet with a Taylor-based Reynolds number Reλ≃230. Analysis is performed at seven locations from 15 diameters up to 45 diameters downstream. Eulerian Analysis is first carried out to obtain critical parameters of the jet and relevant scales, namely the Kolmogorov and large (integral) scales as well as the energy dissipation rate. Lagrangian statistical Analysis is then performed on velocity components stationarised following methods inspired by Batchelor (J. Fluid Mech., vol. 3, 1957, pp. 67–80), which aim to extend stationary Lagrangian theory of turbulent diffusion by Taylor to the case of self-similar flows. The evolution of typical Lagrangian scaling parameters as a function of the developing jet is explored and results show validation of the proposed stationarisation. The universal scaling constant C0 (for the Lagrangian second-order structure function), as well as Eulerian and Lagrangian integral time scales, are discussed in this context. Constant C0 is found to converge to a constant value (of the order of C0=3) within 30 diameters downstream of the nozzle. Finally, the occurrence of finite particle size effects is investigated through consideration of acceleration-dependent quantities

  • Lagrangian diffusion properties of a free shear turbulent jet
    2021
    Co-Authors: Viggiano Bianca, Basset Thomas, Solovitz Stephen, Barois Thomas, Gibert Mathieu, Mordant Nicolas, Chevillard Laurent, Volk Romain, Bourgoin Mickaël, Cal, Raúl Bayoán
    Abstract:

    A Lagrangian experimental study of an axisymmetric turbulent water jet is performed to investigate the highly anisotropic and inhomogeneous flow field. The measurements were conducted within a Lagrangian exploration module, an icosahedron apparatus, to facilitate optical access of three cameras. The stereoscopic particle tracking velocimetry results in three component tracks of position, velocity and acceleration of the tracer particles within the vertically-oriented jet with a Taylor-based Reynolds number $\mathcal R_\lambda \simeq 230$. Analysis is performed at seven locations from 15 diameters up to 45 diameters downstream. Eulerian Analysis is first carried out to obtain critical parameters of the jet and relevant scales, namely the Kolmogorov and large turnover (integral) scales as well as the energy dissipation rate. Lagrangian statistical Analysis is then performed on velocity components stationarised following methods inspired by Batchelor (\textit{J. Fluid Mech.}, vol. 3, 1957, pp. 67-80) which aim to extend stationary Lagrangian theory of turbulent diffusion by Taylor to the case of self-similar flows. The evolution of typical Lagrangian scaling parameters as a function of the developing jet is explored and results show validation of the proposed stationarisation. The universal scaling constant $C_0$ (for the Lagrangian second-order structure function), as well as Eulerian and Lagrangian integral time scales are discussed in this context. $C_0$ is found to converge to a constant value (of the order of $C_0 = 3$) within 30 diameters downstream of the nozzle. Finally, the existence of finite particle size effects are investigated through consideration of acceleration dependent quantities

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

  • Lagrangian diffusion properties of a free shear turbulent jet
    'Cambridge University Press (CUP)', 2021
    Co-Authors: Viggiano Bianca, Basset Thomas, Solovitz Stephen, Barois Thomas, Gibert Mathieu, Mordant Nicolas, Chevillard Laurent, Volk Romain, Bourgoin Mickaël, Cal, Raúl Bayoán
    Abstract:

    International audienceA Lagrangian experimental study of an axisymmetric turbulent water jet is performed to investigate the highly anisotropic and inhomogeneous flow field. Measurements are conducted within a Lagrangian exploration module, an icosahedron apparatus, to facilitate optical access of three cameras. Stereoscopic particle tracking velocimetry results in three-component tracks of position, velocity and acceleration of the tracer particles within the vertically oriented jet with a Taylor-based Reynolds number Reλ≃230. Analysis is performed at seven locations from 15 diameters up to 45 diameters downstream. Eulerian Analysis is first carried out to obtain critical parameters of the jet and relevant scales, namely the Kolmogorov and large (integral) scales as well as the energy dissipation rate. Lagrangian statistical Analysis is then performed on velocity components stationarised following methods inspired by Batchelor (J. Fluid Mech., vol. 3, 1957, pp. 67–80), which aim to extend stationary Lagrangian theory of turbulent diffusion by Taylor to the case of self-similar flows. The evolution of typical Lagrangian scaling parameters as a function of the developing jet is explored and results show validation of the proposed stationarisation. The universal scaling constant C0 (for the Lagrangian second-order structure function), as well as Eulerian and Lagrangian integral time scales, are discussed in this context. Constant C0 is found to converge to a constant value (of the order of C0=3) within 30 diameters downstream of the nozzle. Finally, the occurrence of finite particle size effects is investigated through consideration of acceleration-dependent quantitie

  • Lagrangian Diffusion Properties of a Free Shear Turbulent Jet
    PDXScholar, 2021
    Co-Authors: Viggiano, Bianca F., Basset Thomas, Solovitz Stephen, Barois Thomas, Gibert Mathieu, Mordant Nicolas, Chevillard Laurent, Volk Romain, Bourgoin Mickaël, Cal, Raúl Bayoán
    Abstract:

    A Lagrangian experimental study of an axisymmetric turbulent water jet is performed to investigate the highly anisotropic and inhomogeneous flow field. Measurements are conducted within a Lagrangian exploration module, an icosahedron apparatus, to facilitate optical access of three cameras. Stereoscopic particle tracking velocimetry results in three-component tracks of position, velocity and acceleration of the tracer particles within the vertically oriented jet with a Taylor-based Reynolds number Reλ≃230. Analysis is performed at seven locations from 15 diameters up to 45 diameters downstream. Eulerian Analysis is first carried out to obtain critical parameters of the jet and relevant scales, namely the Kolmogorov and large (integral) scales as well as the energy dissipation rate. Lagrangian statistical Analysis is then performed on velocity components stationarised following methods inspired by Batchelor (J. Fluid Mech., vol. 3, 1957, pp. 67–80), which aim to extend stationary Lagrangian theory of turbulent diffusion by Taylor to the case of self-similar flows. The evolution of typical Lagrangian scaling parameters as a function of the developing jet is explored and results show validation of the proposed stationarisation. The universal scaling constant C0 (for the Lagrangian second-order structure function), as well as Eulerian and Lagrangian integral time scales, are discussed in this context. Constant C0 is found to converge to a constant value (of the order of C0=3) within 30 diameters downstream of the nozzle. Finally, the occurrence of finite particle size effects is investigated through consideration of acceleration-dependent quantities

  • Lagrangian diffusion properties of a free shear turbulent jet
    2021
    Co-Authors: Viggiano Bianca, Basset Thomas, Solovitz Stephen, Barois Thomas, Gibert Mathieu, Mordant Nicolas, Chevillard Laurent, Volk Romain, Bourgoin Mickaël, Cal, Raúl Bayoán
    Abstract:

    A Lagrangian experimental study of an axisymmetric turbulent water jet is performed to investigate the highly anisotropic and inhomogeneous flow field. The measurements were conducted within a Lagrangian exploration module, an icosahedron apparatus, to facilitate optical access of three cameras. The stereoscopic particle tracking velocimetry results in three component tracks of position, velocity and acceleration of the tracer particles within the vertically-oriented jet with a Taylor-based Reynolds number $\mathcal R_\lambda \simeq 230$. Analysis is performed at seven locations from 15 diameters up to 45 diameters downstream. Eulerian Analysis is first carried out to obtain critical parameters of the jet and relevant scales, namely the Kolmogorov and large turnover (integral) scales as well as the energy dissipation rate. Lagrangian statistical Analysis is then performed on velocity components stationarised following methods inspired by Batchelor (\textit{J. Fluid Mech.}, vol. 3, 1957, pp. 67-80) which aim to extend stationary Lagrangian theory of turbulent diffusion by Taylor to the case of self-similar flows. The evolution of typical Lagrangian scaling parameters as a function of the developing jet is explored and results show validation of the proposed stationarisation. The universal scaling constant $C_0$ (for the Lagrangian second-order structure function), as well as Eulerian and Lagrangian integral time scales are discussed in this context. $C_0$ is found to converge to a constant value (of the order of $C_0 = 3$) within 30 diameters downstream of the nozzle. Finally, the existence of finite particle size effects are investigated through consideration of acceleration dependent quantities