Pressure drop characteristics of two-phase flow in a vertical rod bundle with support plates

Experiments have been conducted for single-phase water and two-phase air-water flow in a vertical seven-rod bundle with support plates. Measurements were made for two-phase pressure drops under conditions of total mass velocity from 200 to 850 kg m^-2s^-1, quality from 9 × 10^-4 to 0.27 and pressure from 110 to 230 kPa. Single-phase experimental results show that new developed correlations to obtain frictional factors in the vertical rod bundle and loss coefficients of support plates were in good agreement with experimental data. With respect to two-phase results, the homogeneous flow model dramatically overestimated two-phase friction multipliers in vertical rod bundles, while the new developed correlation presented good predictions. When calculating two-phase pressure drops in support plates, a new defined two-phase multiplier of local pressure drop in support plates was suggested. The two-phase multiplier data of support plates, in which an obvious mass velocity effect was observed, could be fit well in terms of Martinelli parameter and a dimensionless mass velocity. The new correlation developed for two-phase multipliers of support plates was successfully in predicting the experimental data.