Projects & Programs
Visualization of Phase Change Phenomena in Microstructures
Microchannel devices such as micro heat exchangers have a wide variety of applications. There is a need to optimize their performances. This is not a simple problem because it requires a good understanding of the correlation of the pressure drop and the flow regime in these devices, and published data only apply to channel sizes of 0.3 mm or greater. Existing correlations, therefore, may not apply in microchannels. An important step to solve this problem is to study how the phase change in the two-phase flow in these microchannel devices affects the pressure drop. PNNL Scientist David Pfund has developed a technique to visualize the phase change phenomena in these channels that may lead to new data for the optimization of micro-heat exchanger design.