Pressure Drop Characteristics of R134a Two-Phase Flow in a Horizontal Rectangular Microchannel

Adiabatic two-phase flow pressure drop of R134a have been investigated experimentally in a rectangular channel with hydraulic diameter of 0.14 mm. Single-phase flow experiments were also conducted with liquid and vapor R134a, and an empirical correlation was developed for the turbulent flow regime. The parameter ranges examined for two-phase flow are: mass flux from 158 to 785 kg m⁻² s⁻¹; vapor quality from 0.01 to 0.95; and saturation temperature at about 24 ~ 32°C. The experimental data were compared with twelve existing correlations. The homogeneous model and the Mishima and Hibiki (1996) correlation give better predictions than any other correlations.