Direct numerical simulation was performed for a spatially advancing turbulent flow in a two-dimensional curved channel. The radius ratio of the curved part, α , was set at 0.92, the same as Kobayashi et al.'s experiment. And the friction Reynolds number, Re τ0 , was set at 550. Numerically solved mean velocity field showed trends consistent with the experiment. As a result, the validity of the simulation was confirmed. Instantaneous flow field implied that micro-scale structures near the outer wall were related to the birth and growth of large-scale vortices.

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Solar thermochemical energy storage systems, utilize the entire spectrum of solar radiation to drive endothermic chemical reactions, have received great interest in concentrated solar power applications during the past years. Storing solar radiation as chemical energy during the day can be utilized at night times and cloudy days. In these solar thermochemical processes, chemically reactive and radiatively participating multiphase flows in various regimes are frequently encountered. Numerical modeling of multiphase flows assists to optimize the processes of solar thermochemical reactors by reducing the time-consuming experimental testing and cost. In this study, an Euler-Euler two phase model has been developed to investigate the fluidization behavior of 2:1 ironmanganese oxide redox and spinel particles for thermochemical and sensible heat storage systems respectively. In order to validate the model, a pseudo 2D experimental set up has been made. Experimental and numerical results have been compared for various conditions. The effect of gas flow rate on the fluidization behavior has been analyzed.

Direct numerical simulation (DNS) was performed for a turbulent channel flow with the time‐mean temperature linearly varying in the spanwise direction. Spanwise heat transfer in wall turbulence was explored in this simple case where the turbulent heat flux has only a spanwise component. The computed flow field was confirmed to be in good agreement with the DNS database constructed by Kasagi and colleagues (1992). The general trend of the presently calculated spanwise eddy diffusivity of heat is similar to the experimental data reported by Maekawa and colleagues (1991). However, there is a considerable discrepancy between their results in the vicinity of the wall. The numerical results demonstrate that the spanwise turbulent heat flux is nearly in local equilibrium over the whole channel width excluding the viscous sublayer. © 1999 Scripta Technica, Heat Trans Asian Res, 28(8): 675–686, 1999

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