flow boiling, heat transer, rectangular tube, correlation
This work is focused on the saturated flow boiling refrigerants in horizontal square tubes. The relevance and novelty of the study is established in literature review. The experimental apparatus, methods, and data interpretation are described in detail. Experimental data from flow boiling experiments performed in a square tube having 7 mm x 7 mm cross section are presented, for R134a at mass fluxes ranging from 100 to 250kg/(m2s), and a controlled inlet quality from 0 to 90%. The system pressure was maintained at about 500 kPa for these experiments. The experimental data are compared to correlations available in literature. The departure of the experimental data from these correlations suggests the need for developing similar correlations for tubes having rectangular cross sections.