Multiphase heat transfer is an important mechanism across wide variety of engineering disciplines. The prediction of the heat transfer rate as a function of flow conditions and temperature has been based almost exclusively on experimentally derived correlations. The quality of these correlations depends on the accuracy and resolution of the measurement technique. In addition to the complexities of flow boiling phenomenon in earth gravity, engineering design of space systems requires knowledge of any gravity dependence for heat transfer characteristics.

Current research has shown significant variation in the heat transfer characteristics during pool boiling as a function of gravity magnitude. Research into flow boiling in variable gravity environments is extremely limited at this time, but necessary before multiphase systems can be designed for space.

The objective of this study is to develop, validate, and use a unique infrared thermometry method to quantify the heat transfer characteristics of flow boiling in earth gravity, prior to use of the apparatus in variable gravity environments. This new method allows high spatial and temporal resolution measurements, while simultaneously visualizing the flow phenomenon. Validation of this technique will be demonstrated by comparison to accepted correlations for single and multiphase heat transfer in earth gravity environments.