Global-symmetry breaking of turbulent puffs in rectangular duct flow

2020 ◽  
Vol 2020 (0) ◽  
pp. OS02-04
Author(s):  
Akito KUNIHIRO ◽  
Masaki SHIMIZU ◽  
Genta KAWAHARA
Keyword(s):  
Symmetry Breaking ◽  
Global Symmetry ◽  
Duct Flow ◽  
Rectangular Duct

scholarly journals Effects of small boundary perturbation on the MHD duct flow

2017 ◽  
Vol 44 (1) ◽  
pp. 83-101 ◽  
Author(s):  
Ulavathi Mahabaleshwar ◽  
Igor Pazanin ◽  
Marko Radulovic ◽  
Francisco Suárez-Grau
Keyword(s):  
Magnetic Field ◽  
Asymptotic Solution ◽  
Asymptotic Analysis ◽  
Cross Section ◽  
Transverse Magnetic ◽  
Boundary Perturbation ◽  
Duct Flow ◽  
Rectangular Duct ◽  
Induced Magnetic Field ◽  
Explicit Formulae

In this paper, we investigate the effects of small boundary perturbation on the laminar motion of a conducting fluid in a rectangular duct under applied transverse magnetic field. A small boundary perturbation of magnitude ? is applied on cross-section of the duct. Using the asymptotic analysis with respect to ?, we derive the effective model given by the explicit formulae for the velocity and induced magnetic field. Numerical results are provided confirming that the considered perturbation has nonlocal impact on the asymptotic solution.

scholarly journals Modified boundary integral method for pressure driven MHD duct flow

1989 ◽  
Vol 12 (1) ◽  
pp. 159-174
Author(s):  
B. D. Aggarwala ◽  
P. D. Ariel
Keyword(s):  
Magnetic Field ◽  
Integral Method ◽  
Boundary Integral ◽  
Boundary Integral Method ◽  
Duct Flow ◽  
Rectangular Duct ◽  
Computationally Efficient ◽  
Electrically Conducting ◽  
Flow Through ◽  
The Magnetic Field

In this paper, we investigate the flow of a viscous, Incompressible, electrically conducting fluid through a rectangular duct in the presence of a magnetic field, when one of the boundaries perpedicular to the magnetic field is partly conducting and partly Insulating, by a modified Boundary Integral Method.Three problems are considered (i) flow through an infinite channel, (ii) flow through a rectangular duct when the conducting part is symmetrically situated, and (iii) flow through a rectangular duct when the conducting part is arbltrarily positioned.Such problems have been studied before by asymptotic means for large values of M, the Hartmann number. Hoverer, the present modification of the Boundary Integral Method renders the problem computationally efficient and provides a reliable numerical solution for all values of M. For large M, our coputation time decreases significantly.

scholarly journals Kaonic Atoms to Investigate Global Symmetry Breaking

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 547 ◽  
Author(s):  
Catalina Curceanu ◽  
Carlo Guaraldo ◽  
Diana Sirghi ◽  
Aidin Amirkhani ◽  
Ata Baniahmad ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Precise Measurement ◽  
Relative Energy ◽  
Kaonic Hydrogen ◽  
Global Symmetry ◽  
Nucleus Interaction ◽  
Kaonic Atoms ◽  
Kaonic Deuterium ◽  
Energy Quantum ◽  
Scattering Lengths

Kaonic atoms measure the antikaon-nucleus interaction at almost zero relative energy, allowing one to determine basic low-energy quantum chromodynamics (QCD) quantities, namely, the antikaon-nucleon ( K ¯ N) scattering lengths. The latter are important for extracting the sigma terms which are built on the symmetry breaking part of the Hamiltonian, thereby providing a measure of chiral and SU(3) symmetries breaking. After discussing the sigma terms and their relations to the kaonic atoms, we describe the most precise measurement in the literature of kaonic hydrogen, performed at LNF-INFN by the SIDDHARTA experiment. Kaonic deuterium is still to be measured, and two experiments are planned. The first, SIDDHARTA-2 at LNF-INFN was installed on DA Φ NE in spring 2019 and will collect data in 2020. The second, E57 at J-PARC, will become operative in 2021.

A Reynolds Stress Model for Turbulent Corner Flows—Part II: Comparisons Between Theory and Experiment

1976 ◽  
Vol 98 (2) ◽  
pp. 269-276 ◽  
Author(s):  
F. B. Gessner ◽  
J. K. Po
Keyword(s):  
Reynolds Stress ◽  
Reynolds Stress Model ◽  
Length Variation ◽  
Stress Model ◽  
Duct Flow ◽  
Rectangular Duct ◽  
Proposed Model ◽  
Alternate Model ◽  
Corner Flows ◽  
Good Agreement

The applicability of the Reynolds stress model developed in Part I to fully developed rectangular duct flow is investigated. Two sets of experimental data are analyzed in order to prescribe a representative mixing length variation and appropriate values for the constants in the model. Predicted Reynolds stress values are in good agreement with their experimental counterparts for both sets of data. These results are compared with predictions referred to an alternate model in order to explain discrepancies observed in a previous study. Possible extensions of the proposed model to increase its flexibility are discussed.

Numerical Simulation of MHD Rectangular Duct Flow with FCI Based on Magnetic Induction Method

2012 ◽  
Vol 452-453 ◽  
pp. 344-347
Author(s):  
Tian Neng Xu ◽  
Jie Mao ◽  
Hua Chen Pan
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Liquid Metal ◽  
Magnetic Induction ◽  
Metal Flow ◽  
Duct Flow ◽  
Rectangular Duct ◽  
Induction Method ◽  
Pressure Equalization ◽  
Liquid Metal Flow

In dual-coolant and self-cooled blanket concepts, the magnetohydrodynamic (MHD) pressure drop is a key point that should be considered. In order to reduce the high MHD drop, it requires an understanding of the liquid metal flow in rectangular duct with FCI. In this paper, two cases that have different pressure equalization slot widths were simulated based on MHD module of FLUENT. It is found that with different widths of pressure equalization slot, velocity distribution and pressure drop changes a lot.

Measurements of Developing and Fully Developed Heat Transfer Coefficients along a Periodically Interrupted Surface

1979 ◽  
Vol 101 (2) ◽  
pp. 211-216 ◽  
Author(s):  
N. Cur ◽  
E. M. Sparrow
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Pressure Drop ◽  
Plate Thickness ◽  
Turbulent Regime ◽  
Duct Flow ◽  
Rectangular Duct ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Interrupted Surface

The heat transfer and pressure drop characteristics for an array of colinear, equally spaced plates aligned parallel to the flow in a flat rectangular duct have been studied experimentally. The periodic interruptions (i.e., the gaps between the plates) preclude the attainment of hydrodynamic and thermal development of the type that is encountered in conventional duct flows, but a periodic fully developed regime can exist. Measurements of the heat transfer coefficients for the successive plates of the array affirmed the periodically developed regime and demonstrated the developmental pattern leading to its attainment. The thickness of the plates in the array was varied parametrically. In general, the Nusselt number increases with plate thickness. Thickness-related increases in the fully developed Nusselt number of up to 65 percent were encountered. The presence of the interruptions serves to augment the heat transfer coefficients. In the fully turbulent regime, the heat transfer coefficients are on the order of twice those for a conventional duct flow. The pressure drop also increases with the plate thickness.

The effects of wall conductivity in magnetohydrodynamic duct flow at high Hartmann numbers

1971 ◽  
Vol 69 (2) ◽  
pp. 337-351 ◽  
Author(s):  
D. J. Temperley ◽  
L. Todd
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Applied Magnetic Field ◽  
Hartmann Number ◽  
Classical Model ◽  
Critical Discussion ◽  
Duct Flow ◽  
Rectangular Duct ◽  
Wall Conductivity ◽  
Expansion Procedure

AbstractLaminar motion of a conducting fluid in a rectangular duct is discussed. The applied magnetic field is uniform and parallel to one pair of sides of the duct. Classical theory is used and it is shown that the two successive limiting processes, lim (σwall → ∞; hσ wall → a finite, constant limit) and lim (M → ∞) are not always freely interchangeable; M being the Hartmann number, σwall the electrical conductivity of the duct wall and h the typical ratio of (wall thickness/duct width). A general expansion procedure for M ≫ 1, valid for all types of wall conductivities, is devised. A critical discussion of the deficiencies in the classical model is given.

scholarly journals Stable Spatially Localized Configurations in a Simple Structure—A Global Symmetry-Breaking Approach

2020 ◽  
Vol 142 (1) ◽  
pp. 163-199
Author(s):  
Shrinidhi S. Pandurangi ◽  
Ryan S. Elliott ◽  
Timothy J. Healey ◽  
Nicolas Triantafyllidis
Keyword(s):  
Symmetry Breaking ◽  
Simple Structure ◽  
Global Symmetry

Quantum chromodynamics

2018 ◽  
Author(s):  
Marcos Marino
Keyword(s):  
Symmetry Breaking ◽  
Dirac Operator ◽  
Global Symmetries ◽  
Quantum Chromodynamics ◽  
Random Matrix Theory ◽  
Random Matrix ◽  
Degrees Of Freedom ◽  
Chemical Potential ◽  
Matrix Theory ◽  
Global Symmetry

This article focuses on chiral random matrix theories with the global symmetries of quantum chromodynamics (QCD). In particular, it explains how random matrix theory (RMT) can be applied to the spectra of the Dirac operator both at zero chemical potential, when the Dirac operator is Hermitian, and at non-zero chemical potential, when the Dirac operator is non-Hermitian. Before discussing the spectra of these Dirac operators at non-zero chemical potential, the article considers spontaneous symmetry breaking in RMT and the QCD partition function. It then examines the global symmetries of QCD, taking into account the Dirac operator for a finite chiral basis, as well as the global symmetry breaking pattern and the Goldstone manifold in chiral random matrix theory (chRMT). It also describes the generating function for the Dirac spectrum and applications of chRMT to QCD to gauge degrees of freedom.

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