Magnetoconvection in a horizontal duct flow — A parametric study

Akhmedagaev, Ruslan; Zikanov, Oleg; Belyaev, Ivan; Listratov, Yaroslav

doi:10.1016/j.ijthermalsci.2023.108576

Cited by 4 publications

(1 citation statement)

References 20 publications

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“…The experimental results of Khanal and Lei [24] clearly show that reverse flow can occur at the outlet due to buoyancy effects. Akhmedagaev et al [25] numerically analyzed the mixed convective flow in a horizontal duct with a heated bottom wall and a horizontal transverse magnetic field. The effects of the Reynolds number, Hartmann number, and Grashof number on the flow characteristics were investigated.…”

Section: Introductionmentioning

confidence: 99%

Unsteady Mixed Convection Flows in a Rectangular Duct and Dynamical Behaviors of Flow Channel Insert

Liu,

Wang,

et al. 2024

International Journal of Energy Research

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Buoyancy-assisted upward MHD flows and dynamical behaviors of flow channel insert (FCI) in the dual-coolant lead-lithium (DCLL) blanket are studied numerically. Based on our internally developed and validated solver, the dynamical behaviors of magneto-thermo-fluid-structure coupled multiphysical field are investigated. A large amplitude, low frequency, and quasiperiodic unsteady reverse flow at high Re (31000), high Gr (3.5×1011), and moderate magnetic field (0.7~1.7T) is found in the DCLL blanket. This intricate phenomenon has been discovered for the first time, representing a combination of separate experimental results from Melnikov et al. (2016) and Khanal and Lei (2012). In our study of this large amplitude, low frequency, and quasiperiodic unsteady reverse flows, the importance of the cold helium gas to the instability of fluid flow in the bulk region and the thermal conductivity of the FCI to convection structure and instability are first found and recognized. Additionally, we take into account the effects of the temperature field and flow field on structural deformation and mechanical behavior of FCI, and we have discovered several intriguing phenomena, such as (1) the stability of fluid flow in the bulk region depends on the strength of the heat source, the magnitude of the magnetic field, and thermal conductivity of FCI; (2) the instability and periodicity of the fluid flow are primarily related to the unsteady reverse flow, which rises up and falls down periodically in the bulk region; (3) the physical mechanism of unsteady flow influenced by reverse flow, pressure drop, and Lorentz force has been concluded. It has been discovered that the breakdown of a reverse flow vortex causes a rapid reduction in pressure drop. (4) To avoid this phenomenon in engineering, a phase map of unsteady and steady flows in the DCLL blanket has been created. (5) The quasiperiodic characteristics of solid (flow channel insert) affected by flow are found and analyzed.

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Section: Introductionmentioning

confidence: 99%

Unsteady Mixed Convection Flows in a Rectangular Duct and Dynamical Behaviors of Flow Channel Insert

Liu,

Wang,

et al. 2024

International Journal of Energy Research

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A finite volume and machine learning based investigation of flow dynamics in a vertical duct heated by the sunlight

Leng,

Li,

Al Mesfer

et al. 2024

International Communications in Heat and Mass Transfer

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Experimental research on heat transfer enhancement by a wall-proximity circular cylinder under an axial magnetic field

Wang,

Zhang,

Yang

et al. 2024

Physics of Fluids

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This work experimentally investigates the flow and heat transfer of liquid metal around a cylinder in a rectangular channel with a heated bottom wall under an axial magnetic field. Wall electrical potential probes measure the streamwise and vertical velocity components, while an immersed array probe measures the temperature distribution in the vertical profile. The coupling effects of the gap ratio (ratio of the distance between the center of the cylinder and the wall to the diameter of the cylinder) and the magnetic field on heat transfer enhancement are studied. The experimental results suggest that the Lorentz force suppresses the wall recirculation zone from shedding secondary vortices and alters the trajectory of the vortex street, affecting the thermal boundary layer. The probability density function of temperature indicates that the magnetohydrodynamics effect causes a bimodal distribution due to a quasi-two-dimensional vortex street and a trimodal distribution due to additional secondary vortices. The vortex street notably reduces the thermal boundary layer thickness and the local temperature of the heated wall. The analysis of the correlation coefficients between velocity and temperature fluctuations and the frequency spectrum reveals the physical mechanism enhancing heat transfer. The wall-proximity effect and buoyancy strengthen flow fluctuations and enhance heat transfer. For Ha (Hartmann number) ranging from 161.6 to 646.4, optimal heat transfer occurs at G/d = 1.0, whereas for 808 ≤ Ha ≤ 1131.2, optimal heat transfer is achieved at G/d = 0.5, which is attributed to the coupling effect of the magnetic field and gap flow on vortex dynamics.

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Magnetoconvection in a horizontal duct flow — A parametric study

Cited by 4 publications

References 20 publications

Unsteady Mixed Convection Flows in a Rectangular Duct and Dynamical Behaviors of Flow Channel Insert

Unsteady Mixed Convection Flows in a Rectangular Duct and Dynamical Behaviors of Flow Channel Insert

A finite volume and machine learning based investigation of flow dynamics in a vertical duct heated by the sunlight

Experimental research on heat transfer enhancement by a wall-proximity circular cylinder under an axial magnetic field

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