CU Boulder MCC Lab | Multiphase Flows

JUNE 2011 - MAY 2012

I examined the flow patterns in a Micro Cryogenic Cooler and developed an algorithm to analyze and understand the flow patterns. The phase map generated by my work was used to evaluate the efficiency of the valves on the cooler. Capture and analysis of multiphase flow patterns in a micro cryogenic cooler

To move towards maximum efficiency of a Micro Cryogenic Cooler, it is critical that the flow regimes achieved during use are understood. This cooler used a mixed refrigerant optimized to attain maximum cooling power. This means that inside of the cooler, there is a two-phase (gas-liquid) flow.

I designed a system consisting of a high-speed camera and a microscope to capture images and video of the visible flows inside of the cooler. After capturing this data for different configurations of the cooler, I wrote a script in MatLAB to determine the amount of liquid and amount of gas present in the Joule-Thompson Valve (the blue square on the left side of the video) at a given moment. Using this information in conjunction with data regarding flow rate, temperature differential, and pressure differential across the valve, it will be possible to determine the efficiency of the cooler in a given flow regime.