Effect of magnetic field on near-wall coherent structures and heat transfer in magnetohydrodynamic turbulent channel flow of low Prandtl number fluids

Turbulence and transport of passive scalar in magnetohydrodynamic channel flows with different orientations of magnetic field

“…The diffusion boundary layer becomes wider and the decrease of mean scalar within it becomes smaller. The effect was earlier reported for the wall-normal magnetic field (Yamamoto et al, 2008;Dritselis and Vlachos, 2011). Wee see that it also exists in the cases of spanwise and, to a smaller degree at the same Ha, streamwise field.…”

“…In the case of the MHD channel flow, the structure anisotropy is created by the magnetic field, which transforms flow structures so that they are elongated along the magnetic field lines, and by the mean shear, which stretches the structures in the streamwise direction. One can use different measures of the structure anisotropy, such as two-point correlations (Krasnov et al, 2008), conditional averaging of coherent structures (Dritselis and Vlachos, 2011), or one-point structure tensors (Kassinos et al, 2006;Kassinos et al, 2007). We follow the version of the last approach that uses the anisotropy coefficients…”

“…The effect of the magnetic field on scalar transport in a turbulent channel flow was studied experimentally in Takahashi (1998) and Nakaharai et al (2007) and computationally in Yamamoto et al (2008);; Dritselis and Vlachos (2011). The case of a uniform wall-normal magnetic field was considered.…”

Modeling of MHD turbulent heat transfer in channel flows imposed wall-normal magnetic fields under the various Prandtl number fluids

“…To predict heat transfer degradation during the design process, we attach much value to Reynolds-averaged Navier-Stokes simulation (RANS) [3][4][5]. From this viewpoint, high accuracy models [6,7] of MHD source terms appearing in both the transport equations of turbulent kinetic energy and the turbulent energy dissipation rate have been proposed and passive scalar transport in MHD channel flows of low-Prandlt (Pr) number fluids have been investigated [8,9] by means of Direct numerical simulation (DNS). However, a turbulent heat transfer model under the MHD effects for the high-Pr fluid such as FLiBe has been an unexamined issue until now.…”

Entropy Generation Study of MHD Thermosolutal Convection in a Square Cavity for Different Prandtl Numbers

“…Dritselis and Vlachos. [3] are numerically studied the magnetic field effects on the coherent structures and the associated heat transfer in a turbulent channel flow with constant temperature at the bottom (cold) and top (hot) walls. Two fluids with Prandtl numbers of 0.01 and 0.71 are studied.…”