Experimental investigation on frictional pressure drop of water in vertical rectangular channel

Experimental investigation on saturated flow boiling frictional pressure drop was made during a phase-change process with water. The outlet pressure ranged from 12.1 to 16.1 MPa, mass fluxes from 500 to 1501 kg/(m2 s), heat flux from 737 to 1211 kW/m2, and average quality in test section from 0.05 to 0.38. The rectangular channel had the following dimensions: gap size 2 mm, width 40 mm, and heated length 1000 mm. The experiments were performed with the channel oriented uprightly. is of the experimental data showed that the effects of pressure, mass flux, and quality on frictional pressure drop agreed with those of a conventional channel. Seven state-of-the-art correlations for conventional channel or rectangular channel were evaluated, but they failed to predict the experimental data. According to the results, the quality was an important parameter on predicting frictional pressure drop for steam–water fluid. The Nconf ( N conf = ( 1 / D h ) ( 4 σ / ( g ( ρ l − ρ g ) ) ) could not offer any advantage for the present experiment condition. A new correlation for two-phase frictional pressure drop in rectangular channel was developed on the basis of C coefficient method, all the data were within ±15% of error of prediction. The mean deviation was 3.4%.