Effects of RANS-type Turbulence Models on the Convective Heat Loss Computed by CFD in the Solar Two Power Tower

The effect of the choice of Reynolds-Averaged Navier-Stokes (RANS) type turbulence closure on the Computational Fluid Dynamics (CFD) prediction of convective heat losses from the Solar Two central receiver is considered in this paper for a simplified receiver geometry approximated by flat panels. Computed convective losses at steady state are ∼ 2-3% (1%) of the total power absorbed by the receiver, at high (low) wind speed, depending on the turbulence model chosen. The simulation results are consistent with those of available correlations for rough cylinders, if the macroscopic roughness due to the panel edges is accounted for, as well as with the low speed experimental results, within the respective error bars.