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The main objective of the present study is to perform an experimental evaluation of five existing correlations for the subchannel pressure drop analysis of a wire-wrapped fuel assembly. For this purpose, a series of water experiments have been performed using a helical wire-wrapped 19-pin fuel assembly for various test parameters. For different test sections with different pitch to rod diameter ratios (P/D) and wire lead length to rod diameter ratios (H/D) have been fabricated. A series of pressure drop measurements were made to obtain friction factors for these four test sections. The new data along with existing data are used to evaluate existing correlations. Both the original and the simplified Cheng and Todreas correlations give the best agreement with experimental data for all flow regions.

A study on the use of momentum interpolation method and higher-order bounded convection schemes for simulation of oscillatory natural convection of liquid metal in a square cavity is presented. The original Rhie and Chow scheme is modified for unsteady flows to obtain the converged solutions which are independent of the time step size. Two higher-order bounded convection schemes, SOUCUP and COPLA are evaluated, together with HYBRID and QUICK, to test their capability for predicting the oscillatory natural convection. The calculations are performed forG r=107, Pr=0.005 employing 42x42 and 82x82 nonuniform grids. The COPLA and QUICK schemes have shown the capability of predicting the oscillatory motion while the HYBRID and SOUCUP schemes have not.