Temperature fluctuations in a liquid metal MHD-flow in a horizontal inhomogeneously heated tube

Belyaev, I. A.; Ivochkin, Yu. P.; Listratov, Yaroslav; Razuvanov, N. G.; Sviridov, V. G.

doi:10.1134/s0018151x15050041

Cited by 21 publications

(27 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Zikanov et al [27] studied MHD flow in a pipe with the lower half of the wall heated and subjected to a transverse magnetic field. Linear stability analysis and direct numerical simulations confirm the existence of convection structures at high H. This verifies experimental observations of temperature fluctuations being suppressed as H is increased, but re-emerging as H is further increased due to secondary flows [28,29]. These results are not limited to the pipe geometry as they have also been detected in duct flows (e.g.…”

Section: Introductionsupporting

confidence: 85%

“…Indeed the H values corresponding to the vertical neutral curves are precisely the critical values found in the Ra-H regime for Re = 0 (see figure 3b). Additionally, the diagram shows that for an appropriate Re, increasing H can cause the flow to transition through both stable and unstable states, as has been observed in previous studies [27][28][29]. The corresponding k c curves are shown in figure 12(b).…”

Section: Critical Reynolds Number At Finite Rayleigh Numberssupporting

confidence: 72%

See 1 more Smart Citation

Linear stability of horizontal, laminar fully developed, quasi-two-dimensional liquid metal duct flow under a transverse magnetic field and heated from below

Pothérat

Sheard

2017

Phys. Rev. Fluids

View full text Add to dashboard Cite

This study considers the linear stability of Poiseuille-Rayleigh-Bénard flows, subjected to a transverse magnetic field to understand the instabilities that arise from the complex interaction between the effects of shear, thermal stratification and magnetic damping. This fundamental study is motivated in part by the desire to enhance heat transfer in the blanket ducts of nuclear fusion reactors. In pure MHD flows, the imposed transverse magnetic field causes the flow to become quasi-two-dimensional and exhibit disturbances that are localised to the horizontal walls. However, the vertical temperature stratification in Rayleigh-Bénard flows feature convection cells that occupy the interior region and therefore the addition of this aspect provides an interesting point for investigation.The linearised governing equations are described by the quasi-two-dimensional model proposed by Sommeria and Moreau [1] which incorporates a Hartmann friction term, and the base flows are considered fully developed and one-dimensional. The neutral stability curves for critical Reynolds and Rayleigh numbers, Rec and Rac, respectively, as functions of Hartmann friction parameter H have been obtained over 10 −2 ≤ H ≤ 10 4 . Asymptotic trends are observed as H → ∞ following Rec ∝ H 1/2 and Rac ∝ H. The linear stability analysis reveals multiple instabilities which alter the flow both within the Shercliff boundary layers and the interior flow, with structures consistent with features from plane Poiseuille and Rayleigh-Bénard flows.

show abstract

Section: Introductionsupporting

confidence: 85%

Section: Critical Reynolds Number At Finite Rayleigh Numberssupporting

confidence: 72%

Linear stability of horizontal, laminar fully developed, quasi-two-dimensional liquid metal duct flow under a transverse magnetic field and heated from below

Pothérat

Sheard

2017

Phys. Rev. Fluids

View full text Add to dashboard Cite

show abstract

“…Similar systems for either ducts or round pipes have been studied experimentally (Genin et al 2011;Belyaev et al 2015;Sahu et al 2020) and numerically (Zikanov et al 2013;Zhang & Zikanov 2014;Vo et al 2017;Listratov et al 2018). The flow is controlled by four dimensionless parameters: the Reynolds, Prandtl, Grashof and Hartmann numbers,…”

Section: Introductionmentioning

confidence: 91%

Magnetoconvection in a horizontal duct flow at very high Hartmann and Grashof numbers

Ruslan¹,

Zikanov²,

Listratov³

2021

Preprint

View full text Add to dashboard Cite

Direct numerical simulations and linear stability analysis are carried out to study mixed convection in a horizontal duct with constant-rate heating applied at the bottom and imposed transverse horizontal magnetic field. A two-dimensional approximation corresponding to the asymptotic limit of very strong magnetic field effect is validated and applied, together with full three-dimensional analysis, to investigate the flow's behaviour in the previously unexplored range of control parameters corresponding to typical conditions of a liquid metal blanket of a nuclear fusion reactor. It is found that the instability to quasi-two-dimensional rolls parallel to the magnetic field discovered at smaller Hartmann and Grashof numbers in earlier studies also occurs in this parameter range. Transport of the rolls by the mean flow leads to magnetoconvective temperature fluctuations of exceptionally high amplitudes. It is also demonstrated that quasi-twodimensional structure of flows at very high Hartmann numbers does not guarantee accuracy of the classical two-dimensional approximation. The accuracy deteriorates at the highest Grashof numbers considered in the study.

show abstract

“…The presence of MCFs in a horizontal round pipe with a lower half of the wall heated was detected in experiments (Genin et al 2011;Belyaev et al 2015) and explained in the linear stability analysis and direct numerical simulations (DNS) by Zikanov et al (2013). Flows of mercury with Pr ≈ 0.022, Re up to 10 5 , Gr up to 10 8 and Ha up to 500 were investigated.…”

Section: Introductionmentioning

confidence: 94%

“…It is also important as an archetypal system, in which the MCFs were first identified (in Genin et al 2011 andZikanov et al 2013, where they were named anomalous fluctuations) and explained. Similar systems for either ducts or round pipes have been studied experimentally (Genin et al 2011;Belyaev et al 2015;Sahu et al 2020) and numerically (Zikanov et al 2013;Zhang & Zikanov 2014;Vo, Pothérat & Sheard 2017;Listratov et al 2018). The flow is controlled by four dimensionless parameters: the Reynolds, Prandtl, Grashof and Hartmann numbers,…”

Section: Introductionmentioning

confidence: 99%

Magnetoconvection in a horizontal duct flow at very high Hartmann and Grashof numbers

2021

View full text Add to dashboard Cite

Direct numerical simulations and linear stability analysis are carried out to study mixed convection in a horizontal duct with constant-rate heating applied at the bottom and an imposed transverse horizontal magnetic field. A two-dimensional approximation corresponding to the asymptotic limit of a very strong magnetic field effect is validated and applied, together with full three-dimensional analysis, to investigate the flow's behaviour in the previously unexplored range of control parameters corresponding to typical conditions of a liquid metal blanket of a nuclear fusion reactor (Hartmann numbers up to $10^4$ and Grashof numbers up to $10^{10}$ ). It is found that the instability to quasi-two-dimensional rolls parallel to the magnetic field discovered at smaller Hartmann and Grashof numbers in earlier studies also occurs in this parameter range. Transport of the rolls by the mean flow leads to magnetoconvective temperature fluctuations of exceptionally high amplitudes. It is also demonstrated that quasi-two-dimensional structure of flows at very high Hartmann numbers does not guarantee accuracy of the classical two-dimensional approximation. The accuracy deteriorates at the highest Grashof numbers considered in the study.

show abstract

Temperature fluctuations in a liquid metal MHD-flow in a horizontal inhomogeneously heated tube

Cited by 21 publications

References 12 publications

Linear stability of horizontal, laminar fully developed, quasi-two-dimensional liquid metal duct flow under a transverse magnetic field and heated from below

Linear stability of horizontal, laminar fully developed, quasi-two-dimensional liquid metal duct flow under a transverse magnetic field and heated from below

Magnetoconvection in a horizontal duct flow at very high Hartmann and Grashof numbers

Magnetoconvection in a horizontal duct flow at very high Hartmann and Grashof numbers

Contact Info

Product

Resources

About