The Experts below are selected from a list of 219 Experts worldwide ranked by ideXlab platform

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

  • Classical Hydrodynamics for analogue space times open channel flows and thin films
    Philosophical Transactions of the Royal Society A, 2020
    Co-Authors: Germain Rousseaux, Hamid Kellay
    Abstract:

    Here we review the way to build analogue space-times in open channel flows by looking at the flow phase diagram and the corresponding analogue experiments performed during the last years in the associated flow regimes. Thin films like the circular jump with different dispersive properties are discussed with the introduction of a brand new system for the next generation of analogue gravity experiments: flowing soap films with their capillary/elastic waves. This article is part of a discussion meeting issue 'The next generation of analogue gravity experiments'.

  • Classical Hydrodynamics for Analogue Spacetimes: Open Channel Flows and Thin Films
    PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 2020
    Co-Authors: Germain Rousseaux, Hamid Kellay
    Abstract:

    Here we review the way to build analogue spacetimes in open channel flows by looking at the flow phase diagram and the corresponding analogue experiments performed during the last years in the associated flow regimes. Thin films like the circular jump with different dispersive properties are discussed with the introduction of a brand new system for the next generation of analogue gravity experiments: flowing soap films with their capillary/elastic waves.

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

  • Classical Hydrodynamics for analogue space times open channel flows and thin films
    Philosophical Transactions of the Royal Society A, 2020
    Co-Authors: Germain Rousseaux, Hamid Kellay
    Abstract:

    Here we review the way to build analogue space-times in open channel flows by looking at the flow phase diagram and the corresponding analogue experiments performed during the last years in the associated flow regimes. Thin films like the circular jump with different dispersive properties are discussed with the introduction of a brand new system for the next generation of analogue gravity experiments: flowing soap films with their capillary/elastic waves. This article is part of a discussion meeting issue 'The next generation of analogue gravity experiments'.

  • Classical Hydrodynamics for Analogue Spacetimes: Open Channel Flows and Thin Films
    PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 2020
    Co-Authors: Germain Rousseaux, Hamid Kellay
    Abstract:

    Here we review the way to build analogue spacetimes in open channel flows by looking at the flow phase diagram and the corresponding analogue experiments performed during the last years in the associated flow regimes. Thin films like the circular jump with different dispersive properties are discussed with the introduction of a brand new system for the next generation of analogue gravity experiments: flowing soap films with their capillary/elastic waves.

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

  • Detection of Kardar–Parisi–Zhang Hydrodynamics in a quantum Heisenberg spin-1/2 chain
    Nature Physics, 2021
    Co-Authors: A. Scheie, Ne Sherman, Se Nagler, Mb Stone, Ge Granroth, Je Moore, M. Dupont, Da Tennant
    Abstract:

    Quantum systems possessing conserved quantities are expected to show quantum fluid properties governed by hydrodynamic equations. This behaviour is now evidenced in a neutron scattering study on the one-dimensional Heisenberg antiferromagnet KCuF_3. Classical Hydrodynamics is a remarkably versatile description of the coarse-grained behaviour of many-particle systems once local equilibrium has been established^ 1 . The form of the hydrodynamical equations is determined primarily by the conserved quantities present in a system. Some quantum spin chains are known to possess, even in the simplest cases, a greatly expanded set of conservation laws, and recent work suggests that these laws strongly modify collective spin dynamics, even at high temperature^ 2 , 3 . Here, by probing the dynamical exponent of the one-dimensional Heisenberg antiferromagnet KCuF_3 with neutron scattering, we find evidence that the spin dynamics are well described by the dynamical exponent z  = 3/2, which is consistent with the recent theoretical conjecture that the dynamics of this quantum system are described by the Kardar–Parisi–Zhang universality class^ 4 , 5 . This observation shows that low-energy inelastic neutron scattering at moderate temperatures can reveal the details of emergent quantum fluid properties like those arising in non-Fermi liquids in higher dimensions.

  • Detection of Kardar–Parisi–Zhang Hydrodynamics in a quantum Heisenberg spin-1/2 chain
    eScholarship University of California, 2021
    Co-Authors: Scheie A, Ne Sherman, Dupont M, Se Nagler, Mb Stone, Ge Granroth, Je Moore, Da Tennant
    Abstract:

    Classical Hydrodynamics is a remarkably versatile description of the coarse-grained behaviour of many-particle systems once local equilibrium has been established . The form of the hydrodynamical equations is determined primarily by the conserved quantities present in a system. Some quantum spin chains are known to possess, even in the simplest cases, a greatly expanded set of conservation laws, and recent work suggests that these laws strongly modify collective spin dynamics, even at high temperature . Here, by probing the dynamical exponent of the one-dimensional Heisenberg antiferromagnet KCuF with neutron scattering, we find evidence that the spin dynamics are well described by the dynamical exponent z = 3/2, which is consistent with the recent theoretical conjecture that the dynamics of this quantum system are described by the Kardar–Parisi–Zhang universality class . This observation shows that low-energy inelastic neutron scattering at moderate temperatures can reveal the details of emergent quantum fluid properties like those arising in non-Fermi liquids in higher dimensions. 1 2,3 4,5

Byung Chan Eu - One of the best experts on this subject based on the ideXlab platform.

  • Generalized hydrodynamic theory of shock waves in rigid diatomic gases.
    Physical Review E, 2001
    Co-Authors: Mazen Al-ghoul, Byung Chan Eu
    Abstract:

    Generalized hydrodynamic theory of shock waves is phenomenologically developed for rigid diatomic molecules. The generalized hydrodynamic equations developed are thermodynamically consistent, obeying the laws of thermodynamics. They reduce to the Navier-Stokes-Fourier theory of the Classical Hydrodynamics in the limit of low Mach number. The theory is applied to study the one-dimensional shock wave structure of nitrogen gas, which is treated as a rigid molecule. An excellent agreement with experiment is obtained for the inverse shock widths up to Mach number 10 reported in the literature. The theory is applicable to arbitrary dimension. On the basis of direction field singularities of the velocity and temperature evolution equations of the theory, it is possible to predict that the shock solutions exist for all Mach numbers in the case of one-dimensional shock waves studied.

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

  • an extended macroscopic transport model for rarefied gas flows in long capillaries with circular cross section
    Physics of Fluids, 2010
    Co-Authors: Peyman Taheri, Henning Struchtrup
    Abstract:

    Pressure-driven and thermally driven rarefied gas flows in long capillaries with circular cross sections are investigated. For both Poiseuille and thermal transpiration flows, a unified theoretical approach is presented based on the linear form of regularized 13-moment (R13) equations. The captured nonequilibrium effects in the processes are compared to available kinetic solutions, and the shortcomings of Classical Hydrodynamics, i.e., the Navier–Stokes–Fourier equations, are highlighted. Breakdown of Onsager’s symmetry is proposed as a criterion to determine the range of applicability of extended macroscopic models. Based on Onsager’s reciprocity relation it is shown that linearized R13 equations provide agreement with kinetic data for moderate Knudsen numbers, Kn≤0.25. Two-way flow pattern and thermomolecular pressure difference in simultaneous pressure-driven and temperature-driven flows are analyzed. Moreover, second-order boundary conditions for velocity slip and temperature jump are derived for the ...

  • effects of rarefaction in microflows between coaxial cylinders
    Physical Review E, 2009
    Co-Authors: Peyma Taheri, Henning Struchtrup
    Abstract:

    Microscale gas flows between two rotating coaxial circular cylinders of infinite length with different temperatures are investigated. Navier-Stokes-Fourier (NSF) and regularized 13-moment (R13) equations in their linear form are used to independently analyze velocity and temperature fields in shear-driven rotary flows, i.e., cylindrical Couette flows. Knudsen boundary layers, which present non-Newtonian stress and non-Fourier heat flow, are predicted as the dominant rarefaction effects in the linear theory. We show that the R13 system yields more accurate results for this boundary value problem by predicting the Knudsen boundary layers, which are not accessible for NSF equations. Furthermore, a set of second-order boundary conditions for velocity slip and temperature jump are derived for the NSF system. It is shown that the proposed boundary conditions effectively improve the Classical Hydrodynamics. The accuracy of NSF and R13 equations is discussed based on their comparison with available direct simulation Monte Carlo data.