Topic
Hartmann number
About: Hartmann number is a research topic. Over the lifetime, 2593 publications have been published within this topic receiving 61342 citations.
Papers published on a yearly basis
Papers
More filters
••
TL;DR: In this paper, a layered channel with porous and nanofluid (CNT-water) layers with sudden area expansion under the magnetic field effects was numerically examined for convective heat transfer.
38 citations
••
TL;DR: In this paper, the authors investigated the effects of an inclined magnetic field on the mixed convection heat transfer characteristics and entropy generation in a nanofluid-filled lid-driven cavity with a wavy surface.
38 citations
••
TL;DR: Ni et al. as mentioned in this paper presented numerical simulations without modeling of an incompressible, laminar, unidirectional circular pipe flow of an electrically conducting fluid under the influence of a uniform transverse magnetic field.
Abstract: We present numerical simulations without modeling of an incompressible, laminar, unidirectional circular pipe flow of an electrically conducting fluid under the influence of a uniform transverse magnetic field. Our computations are performed using a finite-volume code that uses a charge-conserving formulation [called current-conservative formulation in references (Ni et al J Comput Phys 221(1):174–204, 2007, Ni et al J Comput Phys 227(1):205–228, 2007)]. Using high resolution unstructured meshes, we consider Hartmann numbers up to 3000 and various values of the wall conductance ratio c. In the limit $${c{\ll}{\rm Ha}^{-1}}$$
(insulating wall), our results are in excellent agreement with the so-called asymptotic solution (Shercliff J Fluid Mech 1:644–666, 1956). For higher values of the wall conductance ratio, a discrepancy with the asymptotic solution is observed and we exhibit regions of velocity overspeed in the Roberts layers. We characterise these overspeed regions as a function of the wall conductance ratio and the Hartmann number; a set of scaling laws is derived that is coherent with existing asymptotic analysis.
38 citations
••
TL;DR: In this article, the analytical expressions for the developing temperature and local Nusselt number in the entrance region are obtained in the general case, and the associated eigenvalues problem is solved analytically to obtain explicit forms of the eigenfunctions, which correspond to Mathieu's functions.
38 citations
••
TL;DR: In this article, a numerical study is made on the entropy generation and magnetohydrodynamics natural convection of water non-homogeneous nanofluid inside a square enclosure equipped with a heated trapezoidal body.
Abstract: A numerical study is made on the entropy generation and magnetohydrodynamics natural convection of $$\hbox {Al}_{2}\hbox {O}_3$$
-water non-homogeneous nanofluid inside a square enclosure equipped with a heated trapezoidal body. The Galerkin weighted residual finite element method is applied to solve the dimensionless governing equations within the utilized computational domain along with the algorithm of Newton–Raphson iteration that is used for simplifying the nonlinear terms in the equations. The characteristics of fluid flow fields, temperature distributions and entropy generation are studied for an enormous range of the Rayleigh number $$(10^{3}\le Ra \le 10^{6})$$
, volume fraction of nanoparticles (
$$0\le \phi \le 0.04$$
), Hartmann number $$(0\le Ha \le 50)$$
, thermal conductivity of the trapezoidal solid body (
$$k_{\mathrm{w}}=0.5$$
, 0.76, 1.95, 7 and 16) and the height of the trapezoidal solid body (
$$0.15 \le D \le 0.45$$
). It is shown that the streamlines pattern is more sensitive to the increase in the Hartmann number in comparison with the augmentation of the volume fraction of nanoparticles. Also, for a more thermodynamically optimized system, the higher Hartmann number at a higher solid volume fraction of nanofluid is recommended as they show less entropy generation.
38 citations