要約

The paper presents simulations of the lower part of a subchannel featuring characteristics of a PWR reactor. The flow is single-phase, incompressible and of high Reynolds number, but low Richardson number. It is computed by Large Eddy Simulation to focus on the secondary flow and its enhancement by swirl to improve the heat transfer. Three computations are presented, one being the reference and two others with different swirl forcing. The analysis highlights the differences in the structure of the mean flow, the turbulent fluctuations, and their impact on the heat transfer in terms of Nusselt number and turbulent heat fluxes inside the flow.