Two-phase flow pattern map for R170 in a horizontal smooth tube

An experimental investigation of two-phase flow patterns and their transitions for R170 in a horizontal smooth tube was presented. The tests were conducted at various saturation pressures from 1.5 MPa to 2.5 MPa for different mass fluxes from 100 kg m−2 s−1 to 250 kg m−2 s−1 over the entire vapor quality range. The effects of mass flux and saturation pressure on two-phase flow pattern transitions were investigated and analyzed. The physical properties of velocity, viscosity and surface tension are important to the flow pattern transition criteria under our experimental conditions. Several two-phase flow pattern maps in horizontal tubes were compared with the experimental data. Finally, a new flow pattern map for R170 in a horizontal tube based on the Kim et al. (2012) map was carried out.