The 27th Heat Transfer Photogallery was sponsored by the K-22 Heat Transfer Visualization Committee for the 2019 ASME Summer Heat Transfer Conference (SHTC) held in Seattle, WA on July 14–17, 2019, as well as the sixth ASME International Conference of Micro/Nanoscale Heat and Mass Transfer (MNHMT) held in Dalian, China on July 8–10, 2019. Twelve entries were submitted into the Photogallery sessions, and the peer-reviewed evaluation conducted by both the participants and selected HTD K-22 Technical Committee members has identified the six final entries for publication in this ASME Journal of Heat Transfer March issue of 2020.
The purpose of publishing these entries is to draw attention to the innovative features of visualization techniques and esthetic qualities of heat and mass transport phenomena. This Photogallery issue covers multiscale visualizations of mass transport in heat pipes, droplet coalescence, condensation, and boiling heat transfer. To focus on visualization images and schematics for each entry, the text is kept to a minimum and further details should be found directly from the authors. Our wish is that the journal readers enjoy viewing these collections, acquire knowledge of the state-of-the-art visualization techniques, and also promote their participation in the future Photogallery sessions in the SHTC and IMECE conferences.