Pressure drop correlation for a PWR fuel assembly with mixing vane

A pressure drop correlation is developed to estimate the pressure drop across a PWR fuel grid spacer with the mixing vane using a simplified computational fluid dynamics (CFD) analysis. The pressure loss at the mixing-vane spacer was assessed to largely depend on the relative plugging of the flow cross section by the fuel support elements and the mixing vane and the flow acceleration. The correlation coefficients were detemined from the experimental data and the increase of fluid velocity from the CFD analysis. The CFD analysis simulated the spacer and mixing vanes as infinite thin surfaces, and neglected the fuel support elements. The measured loss coefficient for the split-vane spacer was reproduced by new correlation well and showed good agreement with the estimated one from the CFD calculation. the correlation loss coefficients for other mixing-vane spacers are also in good agreement with those that are directly estimated from the predicted pressure drops