This award will support collaborative work between Professor Mihir Sen of the University of Notre Dame and Professor Eduardo Ramos of the Solar Energy Laboratory in Temixco, Mexico. The researchers intend to study nucleate boiling from single-and multiple capillary sites. Variable heat flux will be used as a control parameter to analyze the sequence of bifurcations leading from periodic boiling up to chaos. In order to assess the contribution of phase change to the observed phenomena, a similar study without phase change, but with the controlled injection of an inert gas, will also be carried out. In this case the mass flow rate of the inert gas will be the relevant bifurcation parameter. The bulk of the phase change work will be done in the U.S., while most of the inert gas studies will be in Mexico. One part of the work will consist of extensive observation and interpretation of an experimental nature. Another will be the development of a suitable analytical model for the processes which can qualitatively explain the observed phenomena. Though the cylindrical capillary structure chosen for study is the simplest geometry from a basic point of view, results from this study are expected to advance our fundamental understanding of boiling. As such the proposed work has potential application to the design of thermal equipment operating under boiling conditions and to the preparation of structured surfaces for enhanced heat transfer.
