Experimental evaluation of pressure drop elements and fabricated nucleation sites for stabilizing flow boiling in minichannels and microchannels

Satish Kandlikar
Daniel Willistein
John Borrelli

Third international conference on microchannels and minichannels, June 13-15, 2005. The complete proceeding is available at www.asme.org . Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works in February 2014.


The flow boiling process suffers from severe instabilities induced due to nucleation of vapor bubbles in a minichannel or a microchannel in a superheated liquid environment. In an effort to improve the flow boiling stability, several modifications are introduced and experiments are performed on 1054 x 197 μm microchannels with water as the working fluid. The cavity sizes and local liquid and wall conditions required at the onset of nucleation are analyzed. The effects of an inlet pressure restrictor and fabricated nucleation sites are evaluated as a means of stabilizing the flow boiling process and avoiding the backflow phenomena. The results are compared with the unrestricted flow configurations in smooth channels.