Abstract
Qualitative two-phase flow regime data are obtained from high-speed visualization of condensing flows of R-134a at mass fluxes from 75 to 150 kg m−2 s−1 and quality from 0.1 to 0.8 in square microchannels (DH = 0.84 mm) cooled from a single side. Superheated R-134a is distributed into multiple parallel microchannels and then partially condensed, using a counterflow water loop, to the desired quality prior to the inlet of a visualization section. This experimental arrangement mitigates the potential for flow maldistribution. Despite very small heat duties, a low uncertainty in the quality in the visualization section is maintained by enforcing a large temperature difference on the water-side (ΔT > 10 K). For all conditions, annular or annular/wavy type flow were observed, with no distinct intermittent flow. Data are compared with flow macro and mini/microchannel maps, which are shown to over predict the occurrence of intermittent or wavy flow.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
