Energy spectra and turbulence generation in the wake of magnetic obstacles

Numerical simulations and analysis of flow and heat transfer of an electrically conducting fluid past magnetic obstacles are reported. We studied the channel flow configuration with electrically and thermally insulated horizontal walls containing a single or multiple (two or three) magnetic dipoles. Different values of the interactive parameter 0 ? N ? 50 and with a fixed value of Re = 103 are simulated. Detailed insights into energy spectra and turbulence generation in the wake of magnetic obstacles are provided. Although the temperature is a passive scalar, strong dissimilarities between mechanisms of production of the turbulent kinetic energy and temperature variance are observed. The long-term averaged second moments of velocity and temperature revealed the presence of anisotropic turbulence and countergradient diffusion of turbulent heat fluxes. It is concluded that configurations with multiple magnetic dipoles can be utilized in practical applications where the local generation of turbulence and intensification of mixing and heat transfer are required.ChemE/Chemical EngineeringApplied Science